#include "http2/adapter/oghttp2_adapter.h"

#include <string>

#include "absl/strings/str_join.h"
#include "http2/adapter/http2_protocol.h"
#include "http2/adapter/http2_visitor_interface.h"
#include "http2/adapter/mock_http2_visitor.h"
#include "http2/adapter/oghttp2_util.h"
#include "http2/adapter/test_frame_sequence.h"
#include "http2/adapter/test_utils.h"
#include "common/platform/api/quiche_test.h"
#include "common/platform/api/quiche_test_helpers.h"

namespace http2 {
namespace adapter {
namespace test {
namespace {

using ConnectionError = Http2VisitorInterface::ConnectionError;

using spdy::SpdyFrameType;
using testing::_;

enum FrameType {
  DATA,
  HEADERS,
  PRIORITY,
  RST_STREAM,
  SETTINGS,
  PUSH_PROMISE,
  PING,
  GOAWAY,
  WINDOW_UPDATE,
  CONTINUATION,
};

// TODO(birenroy): replace numeric flag values with named constants
enum FrameFlag {
  END_STREAM = 0x01,
  ACK = END_STREAM,
  END_HEADERS = 0x04,
};

class OgHttp2AdapterTest : public testing::Test {
 protected:
  void SetUp() override {
    OgHttp2Adapter::Options options{.perspective = Perspective::kServer};
    adapter_ = OgHttp2Adapter::Create(http2_visitor_, options);
  }

  DataSavingVisitor http2_visitor_;
  std::unique_ptr<OgHttp2Adapter> adapter_;
};

TEST_F(OgHttp2AdapterTest, IsServerSession) {
  EXPECT_TRUE(adapter_->IsServerSession());
}

TEST_F(OgHttp2AdapterTest, ProcessBytes) {
  testing::InSequence seq;
  EXPECT_CALL(http2_visitor_, OnFrameHeader(0, 0, 4, 0));
  EXPECT_CALL(http2_visitor_, OnSettingsStart());
  EXPECT_CALL(http2_visitor_, OnSettingsEnd());
  EXPECT_CALL(http2_visitor_, OnFrameHeader(0, 8, 6, 0));
  EXPECT_CALL(http2_visitor_, OnPing(17, false));
  adapter_->ProcessBytes(
      TestFrameSequence().ClientPreface().Ping(17).Serialize());
}

TEST_F(OgHttp2AdapterTest, InitialSettingsNoExtendedConnect) {
  DataSavingVisitor client_visitor;
  OgHttp2Adapter::Options client_options{.perspective = Perspective::kClient,
                                         .max_header_list_bytes = 42,
                                         .allow_extended_connect = false};
  auto client_adapter = OgHttp2Adapter::Create(client_visitor, client_options);

  DataSavingVisitor server_visitor;
  OgHttp2Adapter::Options server_options{.perspective = Perspective::kServer,
                                         .allow_extended_connect = false};
  auto server_adapter = OgHttp2Adapter::Create(server_visitor, server_options);

  testing::InSequence s;

  // Client sends the connection preface, including the initial SETTINGS.
  EXPECT_CALL(client_visitor, OnBeforeFrameSent(SETTINGS, 0, 12, 0x0));
  EXPECT_CALL(client_visitor, OnFrameSent(SETTINGS, 0, 12, 0x0, 0));
  {
    int result = client_adapter->Send();
    EXPECT_EQ(0, result);
    absl::string_view data = client_visitor.data();
    EXPECT_THAT(data, testing::StartsWith(spdy::kHttp2ConnectionHeaderPrefix));
    data.remove_prefix(strlen(spdy::kHttp2ConnectionHeaderPrefix));
    EXPECT_THAT(data, EqualsFrames({SpdyFrameType::SETTINGS}));
  }

  // Server sends the connection preface, including the initial SETTINGS.
  EXPECT_CALL(server_visitor, OnBeforeFrameSent(SETTINGS, 0, 0, 0x0));
  EXPECT_CALL(server_visitor, OnFrameSent(SETTINGS, 0, 0, 0x0, 0));
  {
    int result = server_adapter->Send();
    EXPECT_EQ(0, result);
    absl::string_view data = server_visitor.data();
    EXPECT_THAT(data, EqualsFrames({SpdyFrameType::SETTINGS}));
  }

  // Client processes the server's initial bytes, including initial SETTINGS.
  EXPECT_CALL(client_visitor, OnFrameHeader(0, 0, SETTINGS, 0x0));
  EXPECT_CALL(client_visitor, OnSettingsStart());
  EXPECT_CALL(client_visitor, OnSettingsEnd());
  {
    const int64_t result = client_adapter->ProcessBytes(server_visitor.data());
    EXPECT_EQ(server_visitor.data().size(), static_cast<size_t>(result));
  }

  // Server processes the client's initial bytes, including initial SETTINGS.
  EXPECT_CALL(server_visitor, OnFrameHeader(0, 12, SETTINGS, 0x0));
  EXPECT_CALL(server_visitor, OnSettingsStart());
  EXPECT_CALL(server_visitor,
              OnSetting(Http2Setting{Http2KnownSettingsId::ENABLE_PUSH, 0u}))
      .Times(2);
  EXPECT_CALL(
      server_visitor,
      OnSetting(Http2Setting{Http2KnownSettingsId::MAX_HEADER_LIST_SIZE, 42u}))
      .Times(2);
  EXPECT_CALL(server_visitor, OnSettingsEnd());
  {
    const int64_t result = server_adapter->ProcessBytes(client_visitor.data());
    EXPECT_EQ(client_visitor.data().size(), static_cast<size_t>(result));
  }
}

TEST_F(OgHttp2AdapterTest, InitialSettings) {
  DataSavingVisitor client_visitor;
  OgHttp2Adapter::Options client_options{.perspective = Perspective::kClient,
                                         .max_header_list_bytes = 42};
  ASSERT_TRUE(client_options.allow_extended_connect);
  auto client_adapter = OgHttp2Adapter::Create(client_visitor, client_options);

  DataSavingVisitor server_visitor;
  OgHttp2Adapter::Options server_options{.perspective = Perspective::kServer};
  ASSERT_TRUE(server_options.allow_extended_connect);
  auto server_adapter = OgHttp2Adapter::Create(server_visitor, server_options);

  testing::InSequence s;

  // Client sends the connection preface, including the initial SETTINGS.
  EXPECT_CALL(client_visitor, OnBeforeFrameSent(SETTINGS, 0, 12, 0x0));
  EXPECT_CALL(client_visitor, OnFrameSent(SETTINGS, 0, 12, 0x0, 0));
  {
    int result = client_adapter->Send();
    EXPECT_EQ(0, result);
    absl::string_view data = client_visitor.data();
    EXPECT_THAT(data, testing::StartsWith(spdy::kHttp2ConnectionHeaderPrefix));
    data.remove_prefix(strlen(spdy::kHttp2ConnectionHeaderPrefix));
    EXPECT_THAT(data, EqualsFrames({SpdyFrameType::SETTINGS}));
  }

  // Server sends the connection preface, including the initial SETTINGS.
  EXPECT_CALL(server_visitor, OnBeforeFrameSent(SETTINGS, 0, 6, 0x0));
  EXPECT_CALL(server_visitor, OnFrameSent(SETTINGS, 0, 6, 0x0, 0));
  {
    int result = server_adapter->Send();
    EXPECT_EQ(0, result);
    absl::string_view data = server_visitor.data();
    EXPECT_THAT(data, EqualsFrames({SpdyFrameType::SETTINGS}));
  }

  // Client processes the server's initial bytes, including initial SETTINGS.
  EXPECT_CALL(client_visitor, OnFrameHeader(0, 6, SETTINGS, 0x0));
  EXPECT_CALL(client_visitor, OnSettingsStart());
  EXPECT_CALL(client_visitor,
              OnSetting(Http2Setting{
                  Http2KnownSettingsId::ENABLE_CONNECT_PROTOCOL, 1u}))
      .Times(2);
  EXPECT_CALL(client_visitor, OnSettingsEnd());
  {
    const int64_t result = client_adapter->ProcessBytes(server_visitor.data());
    EXPECT_EQ(server_visitor.data().size(), static_cast<size_t>(result));
  }

  // Server processes the client's initial bytes, including initial SETTINGS.
  EXPECT_CALL(server_visitor, OnFrameHeader(0, 12, SETTINGS, 0x0));
  EXPECT_CALL(server_visitor, OnSettingsStart());
  EXPECT_CALL(server_visitor,
              OnSetting(Http2Setting{Http2KnownSettingsId::ENABLE_PUSH, 0u}))
      .Times(2);
  EXPECT_CALL(
      server_visitor,
      OnSetting(Http2Setting{Http2KnownSettingsId::MAX_HEADER_LIST_SIZE, 42u}))
      .Times(2);
  EXPECT_CALL(server_visitor, OnSettingsEnd());
  {
    const int64_t result = server_adapter->ProcessBytes(client_visitor.data());
    EXPECT_EQ(client_visitor.data().size(), static_cast<size_t>(result));
  }
}

TEST_F(OgHttp2AdapterTest, AutomaticSettingsAndPingAcks) {
  const std::string frames =
      TestFrameSequence().ClientPreface().Ping(42).Serialize();
  testing::InSequence s;

  // Client preface (empty SETTINGS)
  EXPECT_CALL(http2_visitor_, OnFrameHeader(0, 0, SETTINGS, 0));
  EXPECT_CALL(http2_visitor_, OnSettingsStart());
  EXPECT_CALL(http2_visitor_, OnSettingsEnd());
  // PING
  EXPECT_CALL(http2_visitor_, OnFrameHeader(0, _, PING, 0));
  EXPECT_CALL(http2_visitor_, OnPing(42, false));

  const int64_t read_result = adapter_->ProcessBytes(frames);
  EXPECT_EQ(static_cast<size_t>(read_result), frames.size());

  EXPECT_TRUE(adapter_->want_write());

  // Server preface (SETTINGS)
  EXPECT_CALL(http2_visitor_, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(http2_visitor_, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  // SETTINGS ack
  EXPECT_CALL(http2_visitor_, OnBeforeFrameSent(SETTINGS, 0, 0, 0x1));
  EXPECT_CALL(http2_visitor_, OnFrameSent(SETTINGS, 0, 0, 0x1, 0));
  // PING ack
  EXPECT_CALL(http2_visitor_, OnBeforeFrameSent(PING, 0, _, 0x1));
  EXPECT_CALL(http2_visitor_, OnFrameSent(PING, 0, _, 0x1, 0));

  int send_result = adapter_->Send();
  EXPECT_EQ(0, send_result);
  EXPECT_THAT(http2_visitor_.data(),
              EqualsFrames({SpdyFrameType::SETTINGS, SpdyFrameType::SETTINGS,
                            SpdyFrameType::PING}));
}

TEST_F(OgHttp2AdapterTest, AutomaticPingAcksDisabled) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kServer,
                                  .auto_ping_ack = false};
  auto adapter = OgHttp2Adapter::Create(visitor, options);

  const std::string frames =
      TestFrameSequence().ClientPreface().Ping(42).Serialize();
  testing::InSequence s;

  // Client preface (empty SETTINGS)
  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor, OnSettingsEnd());
  // PING
  EXPECT_CALL(visitor, OnFrameHeader(0, _, PING, 0));
  EXPECT_CALL(visitor, OnPing(42, false));

  const int64_t read_result = adapter->ProcessBytes(frames);
  EXPECT_EQ(static_cast<size_t>(read_result), frames.size());

  EXPECT_TRUE(adapter->want_write());

  // Server preface (SETTINGS)
  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  // SETTINGS ack
  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, 0, 0x1));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, 0, 0x1, 0));
  // No PING ack expected because automatic PING acks are disabled.

  int send_result = adapter->Send();
  EXPECT_EQ(0, send_result);
  EXPECT_THAT(visitor.data(),
              EqualsFrames({SpdyFrameType::SETTINGS, SpdyFrameType::SETTINGS}));
}

TEST(OgHttp2AdapterClientTest, ClientHandles100Headers) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kClient};
  auto adapter = OgHttp2Adapter::Create(visitor, options);

  testing::InSequence s;

  const std::vector<Header> headers1 =
      ToHeaders({{":method", "GET"},
                 {":scheme", "http"},
                 {":authority", "example.com"},
                 {":path", "/this/is/request/one"}});

  const int32_t stream_id1 = adapter->SubmitRequest(headers1, nullptr, nullptr);
  ASSERT_GT(stream_id1, 0);
  QUICHE_LOG(INFO) << "Created stream: " << stream_id1;

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(HEADERS, stream_id1, _, 0x5));
  EXPECT_CALL(visitor, OnFrameSent(HEADERS, stream_id1, _, 0x5, 0));

  int result = adapter->Send();
  EXPECT_EQ(0, result);
  visitor.Clear();

  const std::string stream_frames =
      TestFrameSequence()
          .ServerPreface()
          .Headers(1, {{":status", "100"}},
                   /*fin=*/false)
          .Ping(101)
          .Headers(1,
                   {{":status", "200"},
                    {"server", "my-fake-server"},
                    {"date", "Tue, 6 Apr 2021 12:54:01 GMT"}},
                   /*fin=*/true)
          .Serialize();

  // Server preface (empty SETTINGS)
  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor, OnSettingsEnd());

  EXPECT_CALL(visitor, OnFrameHeader(1, _, HEADERS, 4));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(1));
  EXPECT_CALL(visitor, OnHeaderForStream(1, ":status", "100"));
  EXPECT_CALL(visitor, OnEndHeadersForStream(1));

  EXPECT_CALL(visitor, OnFrameHeader(0, 8, PING, 0));
  EXPECT_CALL(visitor, OnPing(101, false));

  EXPECT_CALL(visitor, OnFrameHeader(1, _, HEADERS, 5));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(1));
  EXPECT_CALL(visitor, OnHeaderForStream(1, ":status", "200"));
  EXPECT_CALL(visitor, OnHeaderForStream(1, "server", "my-fake-server"));
  EXPECT_CALL(visitor,
              OnHeaderForStream(1, "date", "Tue, 6 Apr 2021 12:54:01 GMT"));
  EXPECT_CALL(visitor, OnEndHeadersForStream(1));
  EXPECT_CALL(visitor, OnEndStream(1));
  EXPECT_CALL(visitor, OnCloseStream(1, Http2ErrorCode::HTTP2_NO_ERROR));

  const int64_t stream_result = adapter->ProcessBytes(stream_frames);
  EXPECT_EQ(stream_frames.size(), static_cast<size_t>(stream_result));

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x1));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x1, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(PING, 0, _, 0x1));
  EXPECT_CALL(visitor, OnFrameSent(PING, 0, _, 0x1, 0));

  EXPECT_TRUE(adapter->want_write());
  result = adapter->Send();
  EXPECT_EQ(0, result);
  EXPECT_THAT(visitor.data(),
              EqualsFrames({SpdyFrameType::SETTINGS, SpdyFrameType::PING}));
}

TEST(OgHttp2AdapterClientTest, ClientRejects100HeadersWithFin) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kClient};
  auto adapter = OgHttp2Adapter::Create(visitor, options);

  testing::InSequence s;

  const std::vector<Header> headers1 =
      ToHeaders({{":method", "GET"},
                 {":scheme", "http"},
                 {":authority", "example.com"},
                 {":path", "/this/is/request/one"}});

  const int32_t stream_id1 = adapter->SubmitRequest(headers1, nullptr, nullptr);
  ASSERT_GT(stream_id1, 0);
  QUICHE_LOG(INFO) << "Created stream: " << stream_id1;

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(HEADERS, stream_id1, _, 0x5));
  EXPECT_CALL(visitor, OnFrameSent(HEADERS, stream_id1, _, 0x5, 0));

  int result = adapter->Send();
  EXPECT_EQ(0, result);
  visitor.Clear();

  const std::string stream_frames =
      TestFrameSequence()
          .ServerPreface()
          .Headers(1, {{":status", "100"}}, /*fin=*/false)
          .Headers(1, {{":status", "100"}}, /*fin=*/true)
          .Serialize();

  // Server preface (empty SETTINGS)
  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor, OnSettingsEnd());

  EXPECT_CALL(visitor, OnFrameHeader(1, _, HEADERS, 4));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(1));
  EXPECT_CALL(visitor, OnHeaderForStream(1, ":status", "100"));
  EXPECT_CALL(visitor, OnEndHeadersForStream(1));

  EXPECT_CALL(visitor, OnFrameHeader(1, _, HEADERS, 5));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(1));
  EXPECT_CALL(visitor, OnHeaderForStream(1, ":status", "100"));
  EXPECT_CALL(visitor,
              OnInvalidFrame(
                  1, Http2VisitorInterface::InvalidFrameError::kHttpMessaging));

  const int64_t stream_result = adapter->ProcessBytes(stream_frames);
  EXPECT_EQ(stream_frames.size(), static_cast<size_t>(stream_result));

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x1));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x1, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(RST_STREAM, 1, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(RST_STREAM, 1, _, 0x0, 1));
  EXPECT_CALL(visitor, OnCloseStream(1, Http2ErrorCode::HTTP2_NO_ERROR));

  EXPECT_TRUE(adapter->want_write());
  result = adapter->Send();
  EXPECT_EQ(0, result);
  EXPECT_THAT(visitor.data(), EqualsFrames({SpdyFrameType::SETTINGS,
                                            SpdyFrameType::RST_STREAM}));
}

TEST(OgHttp2AdapterClientTest, ClientRejects100HeadersWithContent) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kClient};
  auto adapter = OgHttp2Adapter::Create(visitor, options);

  testing::InSequence s;

  const std::vector<Header> headers1 =
      ToHeaders({{":method", "GET"},
                 {":scheme", "http"},
                 {":authority", "example.com"},
                 {":path", "/this/is/request/one"}});

  const int32_t stream_id1 = adapter->SubmitRequest(headers1, nullptr, nullptr);
  ASSERT_GT(stream_id1, 0);

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(HEADERS, stream_id1, _, 0x5));
  EXPECT_CALL(visitor, OnFrameSent(HEADERS, stream_id1, _, 0x5, 0));

  int result = adapter->Send();
  EXPECT_EQ(0, result);
  visitor.Clear();

  const std::string stream_frames =
      TestFrameSequence()
          .ServerPreface()
          .Headers(1, {{":status", "100"}},
                   /*fin=*/false)
          .Data(1, "We needed the final headers before data, whoops")
          .Serialize();

  // Server preface (empty SETTINGS)
  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor, OnSettingsEnd());

  EXPECT_CALL(visitor, OnFrameHeader(1, _, HEADERS, 4));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(1));
  EXPECT_CALL(visitor, OnHeaderForStream(1, ":status", "100"));
  EXPECT_CALL(visitor, OnEndHeadersForStream(1));
  EXPECT_CALL(visitor, OnFrameHeader(1, _, DATA, 0));
  EXPECT_CALL(visitor, OnBeginDataForStream(1, _));

  const int64_t stream_result = adapter->ProcessBytes(stream_frames);
  EXPECT_EQ(stream_frames.size(), static_cast<size_t>(stream_result));

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x1));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x1, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(RST_STREAM, 1, _, 0x0));
  EXPECT_CALL(visitor,
              OnFrameSent(RST_STREAM, 1, _, 0x0,
                          static_cast<int>(Http2ErrorCode::PROTOCOL_ERROR)));
  EXPECT_CALL(visitor, OnCloseStream(1, Http2ErrorCode::HTTP2_NO_ERROR));

  EXPECT_TRUE(adapter->want_write());
  result = adapter->Send();
  EXPECT_EQ(0, result);
  EXPECT_THAT(visitor.data(), EqualsFrames({SpdyFrameType::SETTINGS,
                                            SpdyFrameType::RST_STREAM}));
}

TEST(OgHttp2AdapterClientTest, ClientRejects100HeadersWithContentLength) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kClient};
  auto adapter = OgHttp2Adapter::Create(visitor, options);

  testing::InSequence s;

  const std::vector<Header> headers1 =
      ToHeaders({{":method", "GET"},
                 {":scheme", "http"},
                 {":authority", "example.com"},
                 {":path", "/this/is/request/one"}});

  const int32_t stream_id1 = adapter->SubmitRequest(headers1, nullptr, nullptr);
  ASSERT_GT(stream_id1, 0);

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(HEADERS, stream_id1, _, 0x5));
  EXPECT_CALL(visitor, OnFrameSent(HEADERS, stream_id1, _, 0x5, 0));

  int result = adapter->Send();
  EXPECT_EQ(0, result);
  visitor.Clear();

  const std::string stream_frames =
      TestFrameSequence()
          .ServerPreface()
          .Headers(1, {{":status", "100"}, {"content-length", "42"}},
                   /*fin=*/false)
          .Headers(1,
                   {{":status", "200"},
                    {"server", "my-fake-server"},
                    {"date", "Tue, 6 Apr 2021 12:54:01 GMT"}},
                   /*fin=*/true)
          .Serialize();

  // Server preface (empty SETTINGS)
  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor, OnSettingsEnd());

  EXPECT_CALL(visitor, OnFrameHeader(1, _, HEADERS, 4));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(1));
  EXPECT_CALL(visitor, OnHeaderForStream(1, ":status", "100"));
  EXPECT_CALL(
      visitor,
      OnInvalidFrame(1, Http2VisitorInterface::InvalidFrameError::kHttpHeader));

  const int64_t stream_result = adapter->ProcessBytes(stream_frames);
  EXPECT_EQ(stream_frames.size(), static_cast<size_t>(stream_result));

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x1));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x1, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(RST_STREAM, 1, _, 0x0));
  EXPECT_CALL(visitor,
              OnFrameSent(RST_STREAM, 1, _, 0x0,
                          static_cast<int>(Http2ErrorCode::PROTOCOL_ERROR)));
  EXPECT_CALL(visitor, OnCloseStream(1, Http2ErrorCode::HTTP2_NO_ERROR));

  EXPECT_TRUE(adapter->want_write());
  result = adapter->Send();
  EXPECT_EQ(0, result);
  EXPECT_THAT(visitor.data(), EqualsFrames({SpdyFrameType::SETTINGS,
                                            SpdyFrameType::RST_STREAM}));
}

TEST(OgHttp2AdapterClientTest, ClientHandles204WithContent) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kClient};
  auto adapter = OgHttp2Adapter::Create(visitor, options);

  testing::InSequence s;

  const std::vector<Header> headers1 =
      ToHeaders({{":method", "GET"},
                 {":scheme", "http"},
                 {":authority", "example.com"},
                 {":path", "/this/is/request/one"}});

  const int32_t stream_id1 = adapter->SubmitRequest(headers1, nullptr, nullptr);
  ASSERT_GT(stream_id1, 0);

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(HEADERS, stream_id1, _, 0x5));
  EXPECT_CALL(visitor, OnFrameSent(HEADERS, stream_id1, _, 0x5, 0));

  int result = adapter->Send();
  EXPECT_EQ(0, result);
  visitor.Clear();

  const std::string stream_frames =
      TestFrameSequence()
          .ServerPreface()
          .Headers(1, {{":status", "204"}, {"content-length", "2"}},
                   /*fin=*/false)
          .Data(1, "hi")
          .Serialize();

  // Server preface (empty SETTINGS)
  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor, OnSettingsEnd());

  EXPECT_CALL(visitor, OnFrameHeader(1, _, HEADERS, 4));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(1));
  EXPECT_CALL(visitor, OnHeaderForStream(1, ":status", "204"));
  EXPECT_CALL(
      visitor,
      OnInvalidFrame(1, Http2VisitorInterface::InvalidFrameError::kHttpHeader));

  const int64_t stream_result = adapter->ProcessBytes(stream_frames);
  EXPECT_EQ(stream_frames.size(), static_cast<size_t>(stream_result));

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x1));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x1, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(RST_STREAM, 1, _, 0x0));
  EXPECT_CALL(visitor,
              OnFrameSent(RST_STREAM, 1, _, 0x0,
                          static_cast<int>(Http2ErrorCode::PROTOCOL_ERROR)));
  EXPECT_CALL(visitor, OnCloseStream(1, Http2ErrorCode::HTTP2_NO_ERROR));

  EXPECT_TRUE(adapter->want_write());
  result = adapter->Send();
  EXPECT_EQ(0, result);
  EXPECT_THAT(visitor.data(), EqualsFrames({SpdyFrameType::SETTINGS,
                                            SpdyFrameType::RST_STREAM}));
}

TEST(OgHttp2AdapterClientTest, ClientHandles304WithContent) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kClient};
  auto adapter = OgHttp2Adapter::Create(visitor, options);

  testing::InSequence s;

  const std::vector<Header> headers1 =
      ToHeaders({{":method", "GET"},
                 {":scheme", "http"},
                 {":authority", "example.com"},
                 {":path", "/this/is/request/one"}});

  const int32_t stream_id1 = adapter->SubmitRequest(headers1, nullptr, nullptr);
  ASSERT_GT(stream_id1, 0);

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(HEADERS, stream_id1, _, 0x5));
  EXPECT_CALL(visitor, OnFrameSent(HEADERS, stream_id1, _, 0x5, 0));

  int result = adapter->Send();
  EXPECT_EQ(0, result);
  visitor.Clear();

  const std::string stream_frames =
      TestFrameSequence()
          .ServerPreface()
          .Headers(1, {{":status", "304"}, {"content-length", "2"}},
                   /*fin=*/false)
          .Data(1, "hi")
          .Serialize();

  // Server preface (empty SETTINGS)
  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor, OnSettingsEnd());

  EXPECT_CALL(visitor, OnFrameHeader(1, _, HEADERS, 4));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(1));
  EXPECT_CALL(visitor, OnHeaderForStream(1, ":status", "304"));
  EXPECT_CALL(visitor, OnHeaderForStream(1, "content-length", "2"));
  EXPECT_CALL(visitor, OnEndHeadersForStream(1));
  EXPECT_CALL(visitor, OnFrameHeader(1, _, DATA, 0));
  EXPECT_CALL(visitor, OnBeginDataForStream(1, 2));

  const int64_t stream_result = adapter->ProcessBytes(stream_frames);
  EXPECT_EQ(stream_frames.size(), static_cast<size_t>(stream_result));

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x1));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x1, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(RST_STREAM, 1, _, 0x0));
  EXPECT_CALL(visitor,
              OnFrameSent(RST_STREAM, 1, _, 0x0,
                          static_cast<int>(Http2ErrorCode::PROTOCOL_ERROR)));
  EXPECT_CALL(visitor, OnCloseStream(1, Http2ErrorCode::HTTP2_NO_ERROR));

  EXPECT_TRUE(adapter->want_write());
  result = adapter->Send();
  EXPECT_EQ(0, result);
  EXPECT_THAT(visitor.data(), EqualsFrames({SpdyFrameType::SETTINGS,
                                            SpdyFrameType::RST_STREAM}));
}

TEST(OgHttp2AdapterClientTest, ClientHandles304WithContentLength) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kClient};
  auto adapter = OgHttp2Adapter::Create(visitor, options);

  testing::InSequence s;

  const std::vector<Header> headers =
      ToHeaders({{":method", "GET"},
                 {":scheme", "http"},
                 {":authority", "example.com"},
                 {":path", "/this/is/request/one"}});

  const int32_t stream_id = adapter->SubmitRequest(headers, nullptr, nullptr);
  ASSERT_GT(stream_id, 0);

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(HEADERS, stream_id, _, 0x5));
  EXPECT_CALL(visitor, OnFrameSent(HEADERS, stream_id, _, 0x5, 0));

  int result = adapter->Send();
  EXPECT_EQ(0, result);
  visitor.Clear();

  const std::string stream_frames =
      TestFrameSequence()
          .ServerPreface()
          .Headers(1, {{":status", "304"}, {"content-length", "2"}},
                   /*fin=*/true)
          .Serialize();

  // Server preface (empty SETTINGS)
  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor, OnSettingsEnd());

  EXPECT_CALL(visitor, OnFrameHeader(1, _, HEADERS, 5));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(1));
  EXPECT_CALL(visitor, OnHeaderForStream(1, ":status", "304"));
  EXPECT_CALL(visitor, OnHeaderForStream(1, "content-length", "2"));
  EXPECT_CALL(visitor, OnEndHeadersForStream(1));
  EXPECT_CALL(visitor, OnEndStream(1));
  EXPECT_CALL(visitor, OnCloseStream(1, Http2ErrorCode::HTTP2_NO_ERROR));

  const int64_t stream_result = adapter->ProcessBytes(stream_frames);
  EXPECT_EQ(stream_frames.size(), static_cast<size_t>(stream_result));

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x1));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x1, 0));

  EXPECT_TRUE(adapter->want_write());
  result = adapter->Send();
  EXPECT_EQ(0, result);
  EXPECT_THAT(visitor.data(), EqualsFrames({SpdyFrameType::SETTINGS}));
}

TEST(OgHttp2AdapterClientTest, ClientHandlesTrailers) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kClient};
  auto adapter = OgHttp2Adapter::Create(visitor, options);

  testing::InSequence s;

  const std::vector<Header> headers1 =
      ToHeaders({{":method", "GET"},
                 {":scheme", "http"},
                 {":authority", "example.com"},
                 {":path", "/this/is/request/one"}});

  const char* kSentinel1 = "arbitrary pointer 1";
  const int32_t stream_id1 =
      adapter->SubmitRequest(headers1, nullptr, const_cast<char*>(kSentinel1));
  ASSERT_GT(stream_id1, 0);
  QUICHE_LOG(INFO) << "Created stream: " << stream_id1;

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(HEADERS, stream_id1, _, 0x5));
  EXPECT_CALL(visitor, OnFrameSent(HEADERS, stream_id1, _, 0x5, 0));

  int result = adapter->Send();
  EXPECT_EQ(0, result);
  absl::string_view data = visitor.data();
  EXPECT_THAT(data, testing::StartsWith(spdy::kHttp2ConnectionHeaderPrefix));
  data.remove_prefix(strlen(spdy::kHttp2ConnectionHeaderPrefix));
  EXPECT_THAT(data,
              EqualsFrames({SpdyFrameType::SETTINGS, SpdyFrameType::HEADERS}));
  visitor.Clear();

  const std::string stream_frames =
      TestFrameSequence()
          .ServerPreface()
          .Headers(1,
                   {{":status", "200"},
                    {"server", "my-fake-server"},
                    {"date", "Tue, 6 Apr 2021 12:54:01 GMT"}},
                   /*fin=*/false)
          .Data(1, "This is the response body.")
          .Headers(1, {{"final-status", "A-OK"}},
                   /*fin=*/true)
          .Serialize();

  // Server preface (empty SETTINGS)
  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor, OnSettingsEnd());

  EXPECT_CALL(visitor, OnFrameHeader(1, _, HEADERS, 4));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(1));
  EXPECT_CALL(visitor, OnHeaderForStream(1, ":status", "200"));
  EXPECT_CALL(visitor, OnHeaderForStream(1, "server", "my-fake-server"));
  EXPECT_CALL(visitor,
              OnHeaderForStream(1, "date", "Tue, 6 Apr 2021 12:54:01 GMT"));
  EXPECT_CALL(visitor, OnEndHeadersForStream(1));
  EXPECT_CALL(visitor, OnFrameHeader(1, 26, DATA, 0));
  EXPECT_CALL(visitor, OnBeginDataForStream(1, 26));
  EXPECT_CALL(visitor, OnDataForStream(1, "This is the response body."));
  EXPECT_CALL(visitor, OnFrameHeader(1, _, HEADERS, 5));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(1));
  EXPECT_CALL(visitor, OnHeaderForStream(1, "final-status", "A-OK"));
  EXPECT_CALL(visitor, OnEndHeadersForStream(1));
  EXPECT_CALL(visitor, OnEndStream(1));
  EXPECT_CALL(visitor, OnCloseStream(1, Http2ErrorCode::HTTP2_NO_ERROR));

  const int64_t stream_result = adapter->ProcessBytes(stream_frames);
  EXPECT_EQ(stream_frames.size(), static_cast<size_t>(stream_result));

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x1));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x1, 0));

  EXPECT_TRUE(adapter->want_write());
  result = adapter->Send();
  EXPECT_EQ(0, result);
  EXPECT_THAT(visitor.data(), EqualsFrames({SpdyFrameType::SETTINGS}));
}

TEST(OgHttp2AdapterClientTest, ClientSendsTrailers) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kClient};
  auto adapter = OgHttp2Adapter::Create(visitor, options);

  testing::InSequence s;

  const std::vector<Header> headers1 =
      ToHeaders({{":method", "GET"},
                 {":scheme", "http"},
                 {":authority", "example.com"},
                 {":path", "/this/is/request/one"}});

  const std::string kBody = "This is an example request body.";
  auto body1 = absl::make_unique<TestDataFrameSource>(visitor, false);
  body1->AppendPayload(kBody);
  body1->EndData();

  const int32_t stream_id1 =
      adapter->SubmitRequest(headers1, std::move(body1), nullptr);
  ASSERT_GT(stream_id1, 0);

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(HEADERS, stream_id1, _, 0x4));
  EXPECT_CALL(visitor, OnFrameSent(HEADERS, stream_id1, _, 0x4, 0));
  EXPECT_CALL(visitor, OnFrameSent(DATA, stream_id1, _, 0x0, 0));

  int result = adapter->Send();
  EXPECT_EQ(0, result);
  absl::string_view data = visitor.data();
  EXPECT_THAT(data, testing::StartsWith(spdy::kHttp2ConnectionHeaderPrefix));
  data.remove_prefix(strlen(spdy::kHttp2ConnectionHeaderPrefix));
  EXPECT_THAT(data,
              EqualsFrames({SpdyFrameType::SETTINGS, SpdyFrameType::HEADERS,
                            SpdyFrameType::DATA}));
  visitor.Clear();

  const std::vector<Header> trailers1 =
      ToHeaders({{"extra-info", "Trailers are weird but good?"}});
  adapter->SubmitTrailer(stream_id1, trailers1);

  EXPECT_CALL(visitor, OnBeforeFrameSent(HEADERS, stream_id1, _, 0x5));
  EXPECT_CALL(visitor, OnFrameSent(HEADERS, stream_id1, _, 0x5, 0));

  result = adapter->Send();
  EXPECT_EQ(0, result);
  data = visitor.data();
  EXPECT_THAT(data, EqualsFrames({SpdyFrameType::HEADERS}));
}

TEST(OgHttp2AdapterClientTest, ClientHandlesMetadata) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kClient};
  auto adapter = OgHttp2Adapter::Create(visitor, options);

  testing::InSequence s;

  const std::vector<Header> headers1 =
      ToHeaders({{":method", "GET"},
                 {":scheme", "http"},
                 {":authority", "example.com"},
                 {":path", "/this/is/request/one"}});

  const char* kSentinel1 = "arbitrary pointer 1";
  const int32_t stream_id1 =
      adapter->SubmitRequest(headers1, nullptr, const_cast<char*>(kSentinel1));
  ASSERT_GT(stream_id1, 0);
  QUICHE_LOG(INFO) << "Created stream: " << stream_id1;

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(HEADERS, stream_id1, _, 0x5));
  EXPECT_CALL(visitor, OnFrameSent(HEADERS, stream_id1, _, 0x5, 0));

  int result = adapter->Send();
  EXPECT_EQ(0, result);
  absl::string_view data = visitor.data();
  EXPECT_THAT(data, testing::StartsWith(spdy::kHttp2ConnectionHeaderPrefix));
  data.remove_prefix(strlen(spdy::kHttp2ConnectionHeaderPrefix));
  EXPECT_THAT(data,
              EqualsFrames({SpdyFrameType::SETTINGS, SpdyFrameType::HEADERS}));
  visitor.Clear();

  const std::string stream_frames =
      TestFrameSequence()
          .ServerPreface()
          .Metadata(0, "Example connection metadata")
          .Headers(1,
                   {{":status", "200"},
                    {"server", "my-fake-server"},
                    {"date", "Tue, 6 Apr 2021 12:54:01 GMT"}},
                   /*fin=*/false)
          .Metadata(1, "Example stream metadata")
          .Data(1, "This is the response body.", true)
          .Serialize();

  // Server preface (empty SETTINGS)
  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor, OnSettingsEnd());

  EXPECT_CALL(visitor, OnFrameHeader(0, _, kMetadataFrameType, 4));
  EXPECT_CALL(visitor, OnBeginMetadataForStream(0, _));
  EXPECT_CALL(visitor, OnMetadataForStream(0, _));
  EXPECT_CALL(visitor, OnMetadataEndForStream(0));
  EXPECT_CALL(visitor, OnFrameHeader(1, _, HEADERS, 4));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(1));
  EXPECT_CALL(visitor, OnHeaderForStream(1, ":status", "200"));
  EXPECT_CALL(visitor, OnHeaderForStream(1, "server", "my-fake-server"));
  EXPECT_CALL(visitor,
              OnHeaderForStream(1, "date", "Tue, 6 Apr 2021 12:54:01 GMT"));
  EXPECT_CALL(visitor, OnEndHeadersForStream(1));
  EXPECT_CALL(visitor, OnFrameHeader(1, _, kMetadataFrameType, 4));
  EXPECT_CALL(visitor, OnBeginMetadataForStream(1, _));
  EXPECT_CALL(visitor, OnMetadataForStream(1, _));
  EXPECT_CALL(visitor, OnMetadataEndForStream(1));
  EXPECT_CALL(visitor, OnFrameHeader(1, 26, DATA, 1));
  EXPECT_CALL(visitor, OnBeginDataForStream(1, 26));
  EXPECT_CALL(visitor, OnDataForStream(1, "This is the response body."));
  EXPECT_CALL(visitor, OnEndStream(1));
  EXPECT_CALL(visitor, OnCloseStream(1, Http2ErrorCode::HTTP2_NO_ERROR));

  const int64_t stream_result = adapter->ProcessBytes(stream_frames);
  EXPECT_EQ(stream_frames.size(), static_cast<size_t>(stream_result));

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x1));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x1, 0));

  EXPECT_TRUE(adapter->want_write());
  result = adapter->Send();
  EXPECT_EQ(0, result);
  EXPECT_THAT(visitor.data(), EqualsFrames({SpdyFrameType::SETTINGS}));
}

TEST(OgHttp2AdapterClientTest, ClientHandlesMetadataWithEmptyPayload) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kClient};
  auto adapter = OgHttp2Adapter::Create(visitor, options);

  testing::InSequence s;

  const std::vector<Header> headers1 =
      ToHeaders({{":method", "GET"},
                 {":scheme", "http"},
                 {":authority", "example.com"},
                 {":path", "/this/is/request/one"}});

  const int32_t stream_id = adapter->SubmitRequest(headers1, nullptr, nullptr);
  ASSERT_GT(stream_id, 0);

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(HEADERS, stream_id, _, 0x5));
  EXPECT_CALL(visitor, OnFrameSent(HEADERS, stream_id, _, 0x5, 0));

  int result = adapter->Send();
  EXPECT_EQ(0, result);
  absl::string_view data = visitor.data();
  EXPECT_THAT(data, testing::StartsWith(spdy::kHttp2ConnectionHeaderPrefix));
  data.remove_prefix(strlen(spdy::kHttp2ConnectionHeaderPrefix));
  EXPECT_THAT(data,
              EqualsFrames({SpdyFrameType::SETTINGS, SpdyFrameType::HEADERS}));
  visitor.Clear();

  const std::string stream_frames =
      TestFrameSequence()
          .ServerPreface()
          .Headers(1,
                   {{":status", "200"},
                    {"server", "my-fake-server"},
                    {"date", "Tue, 6 Apr 2021 12:54:01 GMT"}},
                   /*fin=*/false)
          .Metadata(1, "")
          .Data(1, "This is the response body.", true)
          .Serialize();

  // Server preface (empty SETTINGS)
  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor, OnSettingsEnd());

  EXPECT_CALL(visitor, OnFrameHeader(1, _, HEADERS, 4));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(1));
  EXPECT_CALL(visitor, OnHeaderForStream(1, _, _)).Times(3);
  EXPECT_CALL(visitor, OnEndHeadersForStream(1));
  EXPECT_CALL(visitor, OnFrameHeader(1, _, kMetadataFrameType, 4));
  EXPECT_CALL(visitor, OnBeginMetadataForStream(1, _));
  EXPECT_CALL(visitor, OnMetadataEndForStream(1));
  EXPECT_CALL(visitor, OnFrameHeader(1, _, DATA, 1));
  EXPECT_CALL(visitor, OnBeginDataForStream(1, _));
  EXPECT_CALL(visitor, OnDataForStream(1, "This is the response body."));
  EXPECT_CALL(visitor, OnEndStream(1));
  EXPECT_CALL(visitor, OnCloseStream(1, Http2ErrorCode::HTTP2_NO_ERROR));

  const int64_t stream_result = adapter->ProcessBytes(stream_frames);
  EXPECT_EQ(stream_frames.size(), static_cast<size_t>(stream_result));
}

TEST(OgHttp2AdapterClientTest, ClientHandlesMetadataWithPayloadError) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kClient};
  auto adapter = OgHttp2Adapter::Create(visitor, options);

  testing::InSequence s;

  const std::vector<Header> headers =
      ToHeaders({{":method", "GET"},
                 {":scheme", "http"},
                 {":authority", "example.com"},
                 {":path", "/this/is/request/one"}});

  const int32_t stream_id = adapter->SubmitRequest(headers, nullptr, nullptr);
  ASSERT_GT(stream_id, 0);

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(HEADERS, stream_id, _, 0x5));
  EXPECT_CALL(visitor, OnFrameSent(HEADERS, stream_id, _, 0x5, 0));

  int result = adapter->Send();
  EXPECT_EQ(0, result);
  visitor.Clear();

  const std::string stream_frames =
      TestFrameSequence()
          .ServerPreface()
          .Metadata(0, "Example connection metadata")
          .Headers(stream_id,
                   {{":status", "200"},
                    {"server", "my-fake-server"},
                    {"date", "Tue, 6 Apr 2021 12:54:01 GMT"}},
                   /*fin=*/false)
          .Metadata(stream_id, "Example stream metadata")
          .Data(stream_id, "This is the response body.", true)
          .Serialize();

  // Server preface (empty SETTINGS)
  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor, OnSettingsEnd());

  EXPECT_CALL(visitor, OnFrameHeader(0, _, kMetadataFrameType, 4));
  EXPECT_CALL(visitor, OnBeginMetadataForStream(0, _));
  EXPECT_CALL(visitor, OnMetadataForStream(0, _));
  EXPECT_CALL(visitor, OnMetadataEndForStream(0));
  EXPECT_CALL(visitor, OnFrameHeader(stream_id, _, HEADERS, 4));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(stream_id));
  EXPECT_CALL(visitor, OnHeaderForStream(stream_id, _, _)).Times(3);
  EXPECT_CALL(visitor, OnEndHeadersForStream(stream_id));
  EXPECT_CALL(visitor, OnFrameHeader(stream_id, _, kMetadataFrameType, 4));
  EXPECT_CALL(visitor, OnBeginMetadataForStream(stream_id, _));
  EXPECT_CALL(visitor, OnMetadataForStream(stream_id, _))
      .WillOnce(testing::Return(false));
  // Remaining frames are not processed due to the error.
  EXPECT_CALL(visitor, OnConnectionError(ConnectionError::kParseError));

  const int64_t stream_result = adapter->ProcessBytes(stream_frames);
  // Negative integer returned to indicate an error.
  EXPECT_LT(stream_result, 0);

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x1));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x1, 0));

  EXPECT_FALSE(adapter->want_read());
  EXPECT_TRUE(adapter->want_write());
  result = adapter->Send();
  EXPECT_EQ(0, result);
  EXPECT_THAT(visitor.data(), EqualsFrames({SpdyFrameType::SETTINGS}));
}

TEST(OgHttp2AdapterClientTest, ClientHandlesMetadataWithCompletionError) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kClient};
  auto adapter = OgHttp2Adapter::Create(visitor, options);

  testing::InSequence s;

  const std::vector<Header> headers =
      ToHeaders({{":method", "GET"},
                 {":scheme", "http"},
                 {":authority", "example.com"},
                 {":path", "/this/is/request/one"}});

  const int32_t stream_id = adapter->SubmitRequest(headers, nullptr, nullptr);
  ASSERT_GT(stream_id, 0);

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(HEADERS, stream_id, _, 0x5));
  EXPECT_CALL(visitor, OnFrameSent(HEADERS, stream_id, _, 0x5, 0));

  int result = adapter->Send();
  EXPECT_EQ(0, result);
  visitor.Clear();

  const std::string stream_frames =
      TestFrameSequence()
          .ServerPreface()
          .Metadata(0, "Example connection metadata")
          .Headers(stream_id,
                   {{":status", "200"},
                    {"server", "my-fake-server"},
                    {"date", "Tue, 6 Apr 2021 12:54:01 GMT"}},
                   /*fin=*/false)
          .Metadata(stream_id, "Example stream metadata")
          .Data(stream_id, "This is the response body.", true)
          .Serialize();

  // Server preface (empty SETTINGS)
  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor, OnSettingsEnd());

  EXPECT_CALL(visitor, OnFrameHeader(0, _, kMetadataFrameType, 4));
  EXPECT_CALL(visitor, OnBeginMetadataForStream(0, _));
  EXPECT_CALL(visitor, OnMetadataForStream(0, _));
  EXPECT_CALL(visitor, OnMetadataEndForStream(0));
  EXPECT_CALL(visitor, OnFrameHeader(stream_id, _, HEADERS, 4));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(stream_id));
  EXPECT_CALL(visitor, OnHeaderForStream(stream_id, _, _)).Times(3);
  EXPECT_CALL(visitor, OnEndHeadersForStream(stream_id));
  EXPECT_CALL(visitor, OnFrameHeader(stream_id, _, kMetadataFrameType, 4));
  EXPECT_CALL(visitor, OnBeginMetadataForStream(stream_id, _));
  EXPECT_CALL(visitor, OnMetadataForStream(stream_id, _));
  EXPECT_CALL(visitor, OnMetadataEndForStream(stream_id))
      .WillOnce(testing::Return(false));
  // Remaining frames are not processed due to the error.
  EXPECT_CALL(visitor, OnConnectionError(ConnectionError::kParseError));

  const int64_t stream_result = adapter->ProcessBytes(stream_frames);
  // Negative integer returned to indicate an error.
  EXPECT_LT(stream_result, 0);

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x1));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x1, 0));

  EXPECT_FALSE(adapter->want_read());
  EXPECT_TRUE(adapter->want_write());
  result = adapter->Send();
  EXPECT_EQ(0, result);
  EXPECT_THAT(visitor.data(), EqualsFrames({SpdyFrameType::SETTINGS}));
}

TEST(OgHttp2AdapterClientTest, ClientRstStreamWhileHandlingHeaders) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kClient};
  auto adapter = OgHttp2Adapter::Create(visitor, options);

  testing::InSequence s;

  const std::vector<Header> headers1 =
      ToHeaders({{":method", "GET"},
                 {":scheme", "http"},
                 {":authority", "example.com"},
                 {":path", "/this/is/request/one"}});

  const char* kSentinel1 = "arbitrary pointer 1";
  const int32_t stream_id1 =
      adapter->SubmitRequest(headers1, nullptr, const_cast<char*>(kSentinel1));
  ASSERT_GT(stream_id1, 0);
  QUICHE_LOG(INFO) << "Created stream: " << stream_id1;

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(HEADERS, stream_id1, _, 0x5));
  EXPECT_CALL(visitor, OnFrameSent(HEADERS, stream_id1, _, 0x5, 0));

  int result = adapter->Send();
  EXPECT_EQ(0, result);
  absl::string_view data = visitor.data();
  EXPECT_THAT(data, testing::StartsWith(spdy::kHttp2ConnectionHeaderPrefix));
  data.remove_prefix(strlen(spdy::kHttp2ConnectionHeaderPrefix));
  EXPECT_THAT(data,
              EqualsFrames({SpdyFrameType::SETTINGS, SpdyFrameType::HEADERS}));
  visitor.Clear();

  const std::string stream_frames =
      TestFrameSequence()
          .ServerPreface()
          .Headers(1,
                   {{":status", "200"},
                    {"server", "my-fake-server"},
                    {"date", "Tue, 6 Apr 2021 12:54:01 GMT"}},
                   /*fin=*/false)
          .Data(1, "This is the response body.")
          .Serialize();

  // Server preface (empty SETTINGS)
  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor, OnSettingsEnd());

  EXPECT_CALL(visitor, OnFrameHeader(1, _, HEADERS, 4));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(1));
  EXPECT_CALL(visitor, OnHeaderForStream(1, ":status", "200"));
  EXPECT_CALL(visitor, OnHeaderForStream(1, "server", "my-fake-server"));
  EXPECT_CALL(visitor,
              OnHeaderForStream(1, "date", "Tue, 6 Apr 2021 12:54:01 GMT"))
      .WillOnce(testing::DoAll(
          testing::InvokeWithoutArgs([&adapter]() {
            adapter->SubmitRst(1, Http2ErrorCode::REFUSED_STREAM);
          }),
          testing::Return(Http2VisitorInterface::HEADER_RST_STREAM)));

  const int64_t stream_result = adapter->ProcessBytes(stream_frames);
  EXPECT_EQ(stream_frames.size(), static_cast<size_t>(stream_result));

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, 0, 0x1));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, 0, 0x1, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(RST_STREAM, stream_id1, 4, 0x0));
  EXPECT_CALL(visitor,
              OnFrameSent(RST_STREAM, stream_id1, 4, 0x0,
                          static_cast<int>(Http2ErrorCode::REFUSED_STREAM)));
  EXPECT_CALL(visitor, OnCloseStream(1, Http2ErrorCode::HTTP2_NO_ERROR));

  EXPECT_TRUE(adapter->want_write());
  result = adapter->Send();
  EXPECT_EQ(0, result);
  EXPECT_THAT(visitor.data(), EqualsFrames({SpdyFrameType::SETTINGS,
                                            SpdyFrameType::RST_STREAM}));
}

TEST(OgHttp2AdapterClientTest, ClientConnectionErrorWhileHandlingHeaders) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kClient};
  auto adapter = OgHttp2Adapter::Create(visitor, options);

  testing::InSequence s;

  const std::vector<Header> headers1 =
      ToHeaders({{":method", "GET"},
                 {":scheme", "http"},
                 {":authority", "example.com"},
                 {":path", "/this/is/request/one"}});

  const char* kSentinel1 = "arbitrary pointer 1";
  const int32_t stream_id1 =
      adapter->SubmitRequest(headers1, nullptr, const_cast<char*>(kSentinel1));
  ASSERT_GT(stream_id1, 0);
  QUICHE_LOG(INFO) << "Created stream: " << stream_id1;

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(HEADERS, stream_id1, _, 0x5));
  EXPECT_CALL(visitor, OnFrameSent(HEADERS, stream_id1, _, 0x5, 0));

  int result = adapter->Send();
  EXPECT_EQ(0, result);
  absl::string_view data = visitor.data();
  EXPECT_THAT(data, testing::StartsWith(spdy::kHttp2ConnectionHeaderPrefix));
  data.remove_prefix(strlen(spdy::kHttp2ConnectionHeaderPrefix));
  EXPECT_THAT(data,
              EqualsFrames({SpdyFrameType::SETTINGS, SpdyFrameType::HEADERS}));
  visitor.Clear();

  const std::string stream_frames =
      TestFrameSequence()
          .ServerPreface()
          .Headers(1,
                   {{":status", "200"},
                    {"server", "my-fake-server"},
                    {"date", "Tue, 6 Apr 2021 12:54:01 GMT"}},
                   /*fin=*/false)
          .Data(1, "This is the response body.")
          .Serialize();

  // Server preface (empty SETTINGS)
  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor, OnSettingsEnd());

  EXPECT_CALL(visitor, OnFrameHeader(1, _, HEADERS, 4));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(1));
  EXPECT_CALL(visitor, OnHeaderForStream(1, ":status", "200"));
  EXPECT_CALL(visitor, OnHeaderForStream(1, "server", "my-fake-server"));
  EXPECT_CALL(visitor,
              OnHeaderForStream(1, "date", "Tue, 6 Apr 2021 12:54:01 GMT"))
      .WillOnce(
          testing::Return(Http2VisitorInterface::HEADER_CONNECTION_ERROR));
  EXPECT_CALL(visitor, OnConnectionError(ConnectionError::kHeaderError));

  const int64_t stream_result = adapter->ProcessBytes(stream_frames);
  EXPECT_LT(stream_result, 0);

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, 0, 0x1));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, 0, 0x1, 0));

  EXPECT_TRUE(adapter->want_write());
  result = adapter->Send();
  EXPECT_EQ(0, result);
  EXPECT_THAT(visitor.data(), EqualsFrames({SpdyFrameType::SETTINGS}));
}

TEST(OgHttp2AdapterClientTest, ClientConnectionErrorWhileHandlingHeadersOnly) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kClient};
  auto adapter = OgHttp2Adapter::Create(visitor, options);

  testing::InSequence s;

  const std::vector<Header> headers1 =
      ToHeaders({{":method", "GET"},
                 {":scheme", "http"},
                 {":authority", "example.com"},
                 {":path", "/this/is/request/one"}});

  const char* kSentinel1 = "arbitrary pointer 1";
  const int32_t stream_id1 =
      adapter->SubmitRequest(headers1, nullptr, const_cast<char*>(kSentinel1));
  ASSERT_GT(stream_id1, 0);
  QUICHE_LOG(INFO) << "Created stream: " << stream_id1;

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(HEADERS, stream_id1, _, 0x5));
  EXPECT_CALL(visitor, OnFrameSent(HEADERS, stream_id1, _, 0x5, 0));

  int result = adapter->Send();
  EXPECT_EQ(0, result);
  absl::string_view data = visitor.data();
  EXPECT_THAT(data, testing::StartsWith(spdy::kHttp2ConnectionHeaderPrefix));
  data.remove_prefix(strlen(spdy::kHttp2ConnectionHeaderPrefix));
  EXPECT_THAT(data,
              EqualsFrames({SpdyFrameType::SETTINGS, SpdyFrameType::HEADERS}));
  visitor.Clear();

  const std::string stream_frames =
      TestFrameSequence()
          .ServerPreface()
          .Headers(1,
                   {{":status", "200"},
                    {"server", "my-fake-server"},
                    {"date", "Tue, 6 Apr 2021 12:54:01 GMT"}},
                   /*fin=*/true)
          .Serialize();

  // Server preface (empty SETTINGS)
  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor, OnSettingsEnd());

  EXPECT_CALL(visitor, OnFrameHeader(1, _, HEADERS, 5));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(1));
  EXPECT_CALL(visitor, OnHeaderForStream(1, ":status", "200"));
  EXPECT_CALL(visitor, OnHeaderForStream(1, "server", "my-fake-server"));
  EXPECT_CALL(visitor,
              OnHeaderForStream(1, "date", "Tue, 6 Apr 2021 12:54:01 GMT"))
      .WillOnce(
          testing::Return(Http2VisitorInterface::HEADER_CONNECTION_ERROR));
  EXPECT_CALL(visitor, OnConnectionError(ConnectionError::kHeaderError));

  const int64_t stream_result = adapter->ProcessBytes(stream_frames);
  EXPECT_LT(stream_result, 0);

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, 0, 0x1));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, 0, 0x1, 0));

  EXPECT_TRUE(adapter->want_write());
  result = adapter->Send();
  EXPECT_EQ(0, result);
  EXPECT_THAT(visitor.data(), EqualsFrames({SpdyFrameType::SETTINGS}));
}

TEST(OgHttp2AdapterClientTest, ClientRejectsHeaders) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kClient};
  auto adapter = OgHttp2Adapter::Create(visitor, options);

  testing::InSequence s;

  const std::vector<Header> headers1 =
      ToHeaders({{":method", "GET"},
                 {":scheme", "http"},
                 {":authority", "example.com"},
                 {":path", "/this/is/request/one"}});

  const char* kSentinel1 = "arbitrary pointer 1";
  const int32_t stream_id1 =
      adapter->SubmitRequest(headers1, nullptr, const_cast<char*>(kSentinel1));
  ASSERT_GT(stream_id1, 0);
  QUICHE_LOG(INFO) << "Created stream: " << stream_id1;

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(HEADERS, stream_id1, _, 0x5));
  EXPECT_CALL(visitor, OnFrameSent(HEADERS, stream_id1, _, 0x5, 0));

  int result = adapter->Send();
  EXPECT_EQ(0, result);
  absl::string_view data = visitor.data();
  EXPECT_THAT(data, testing::StartsWith(spdy::kHttp2ConnectionHeaderPrefix));
  data.remove_prefix(strlen(spdy::kHttp2ConnectionHeaderPrefix));
  EXPECT_THAT(data,
              EqualsFrames({SpdyFrameType::SETTINGS, SpdyFrameType::HEADERS}));
  visitor.Clear();

  const std::string stream_frames =
      TestFrameSequence()
          .ServerPreface()
          .Headers(1,
                   {{":status", "200"},
                    {"server", "my-fake-server"},
                    {"date", "Tue, 6 Apr 2021 12:54:01 GMT"}},
                   /*fin=*/false)
          .Data(1, "This is the response body.")
          .Serialize();

  // Server preface (empty SETTINGS)
  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor, OnSettingsEnd());

  EXPECT_CALL(visitor, OnFrameHeader(1, _, HEADERS, 4));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(1))
      .WillOnce(testing::Return(false));
  // Rejecting headers leads to a connection error.
  EXPECT_CALL(visitor, OnConnectionError(ConnectionError::kHeaderError));

  const int64_t stream_result = adapter->ProcessBytes(stream_frames);
  EXPECT_LT(stream_result, 0);

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, 0, 0x1));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, 0, 0x1, 0));

  EXPECT_TRUE(adapter->want_write());
  result = adapter->Send();
  EXPECT_EQ(0, result);
  EXPECT_THAT(visitor.data(), EqualsFrames({SpdyFrameType::SETTINGS}));
}

TEST(OgHttp2AdapterClientTest, ClientHandlesSmallerHpackHeaderTableSetting) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kClient};
  auto adapter = OgHttp2Adapter::Create(visitor, options);

  testing::InSequence s;

  const std::vector<Header> headers1 = ToHeaders({
      {":method", "GET"},
      {":scheme", "http"},
      {":authority", "example.com"},
      {":path", "/this/is/request/one"},
      {"x-i-do-not-like", "green eggs and ham"},
      {"x-i-will-not-eat-them", "here or there, in a box, with a fox"},
      {"x-like-them-in-a-house", "no"},
      {"x-like-them-with-a-mouse", "no"},
  });

  const int32_t stream_id1 = adapter->SubmitRequest(headers1, nullptr, nullptr);
  ASSERT_GT(stream_id1, 0);

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(HEADERS, stream_id1, _, 0x5));
  EXPECT_CALL(visitor, OnFrameSent(HEADERS, stream_id1, _, 0x5, 0));

  int result = adapter->Send();
  EXPECT_EQ(0, result);
  visitor.Clear();

  EXPECT_GT(adapter->GetHpackEncoderDynamicTableSize(), 100);

  const std::string stream_frames =
      TestFrameSequence().Settings({{HEADER_TABLE_SIZE, 100u}}).Serialize();
  // Server preface (SETTINGS)
  EXPECT_CALL(visitor, OnFrameHeader(0, 6, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor, OnSetting(Http2Setting{HEADER_TABLE_SIZE, 100u}));
  // Duplicate setting callback due to the way extensions work.
  EXPECT_CALL(visitor, OnSetting(Http2Setting{HEADER_TABLE_SIZE, 100u}));
  EXPECT_CALL(visitor, OnSettingsEnd());

  const int64_t stream_result = adapter->ProcessBytes(stream_frames);
  EXPECT_EQ(stream_frames.size(), static_cast<size_t>(stream_result));

  EXPECT_EQ(adapter->GetHpackEncoderDynamicTableCapacity(), 100);
  EXPECT_LE(adapter->GetHpackEncoderDynamicTableSize(), 100);
}

TEST(OgHttp2AdapterClientTest, ClientHandlesLargerHpackHeaderTableSetting) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kClient};
  auto adapter = OgHttp2Adapter::Create(visitor, options);

  testing::InSequence s;

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));

  int result = adapter->Send();
  EXPECT_EQ(0, result);
  visitor.Clear();

  EXPECT_EQ(adapter->GetHpackEncoderDynamicTableCapacity(), 4096);

  const std::string stream_frames =
      TestFrameSequence().Settings({{HEADER_TABLE_SIZE, 40960u}}).Serialize();
  // Server preface (SETTINGS)
  EXPECT_CALL(visitor, OnFrameHeader(0, 6, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor, OnSetting(Http2Setting{HEADER_TABLE_SIZE, 40960u}));
  // Duplicate setting callback due to the way extensions work.
  EXPECT_CALL(visitor, OnSetting(Http2Setting{HEADER_TABLE_SIZE, 40960u}));
  EXPECT_CALL(visitor, OnSettingsEnd());

  const int64_t stream_result = adapter->ProcessBytes(stream_frames);
  EXPECT_EQ(stream_frames.size(), static_cast<size_t>(stream_result));

  // The increased capacity will not be applied until a SETTINGS ack is
  // serialized.
  EXPECT_EQ(adapter->GetHpackEncoderDynamicTableCapacity(), 4096);

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x1));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x1, 0));

  result = adapter->Send();
  EXPECT_EQ(0, result);
  visitor.Clear();

  EXPECT_EQ(adapter->GetHpackEncoderDynamicTableCapacity(), 40960);
}

TEST(OgHttp2AdapterClientTest, ClientSendsHpackHeaderTableSetting) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kClient};
  auto adapter = OgHttp2Adapter::Create(visitor, options);

  testing::InSequence s;

  const std::vector<Header> headers1 = ToHeaders({
      {":method", "GET"},
      {":scheme", "http"},
      {":authority", "example.com"},
      {":path", "/this/is/request/one"},
  });

  const int32_t stream_id1 = adapter->SubmitRequest(headers1, nullptr, nullptr);
  ASSERT_GT(stream_id1, 0);

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(HEADERS, stream_id1, _, 0x5));
  EXPECT_CALL(visitor, OnFrameSent(HEADERS, stream_id1, _, 0x5, 0));

  int result = adapter->Send();
  EXPECT_EQ(0, result);
  visitor.Clear();

  const std::string stream_frames =
      TestFrameSequence()
          .ServerPreface()
          .SettingsAck()
          .Headers(
              1,
              {{":status", "200"},
               {"server", "my-fake-server"},
               {"date", "Tue, 6 Apr 2021 12:54:01 GMT"},
               {"x-i-do-not-like", "green eggs and ham"},
               {"x-i-will-not-eat-them", "here or there, in a box, with a fox"},
               {"x-like-them-in-a-house", "no"},
               {"x-like-them-with-a-mouse", "no"}},
              /*fin=*/true)
          .Serialize();
  // Server preface (empty SETTINGS)
  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor, OnSettingsEnd());
  // Server acks client's initial SETTINGS.
  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 1));
  EXPECT_CALL(visitor, OnSettingsAck());

  EXPECT_CALL(visitor, OnFrameHeader(1, _, HEADERS, 5));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(1));
  EXPECT_CALL(visitor, OnHeaderForStream(1, _, _)).Times(7);
  EXPECT_CALL(visitor, OnEndHeadersForStream(1));
  EXPECT_CALL(visitor, OnEndStream(1));
  EXPECT_CALL(visitor, OnCloseStream(1, Http2ErrorCode::HTTP2_NO_ERROR));

  const int64_t stream_result = adapter->ProcessBytes(stream_frames);
  EXPECT_EQ(stream_frames.size(), static_cast<size_t>(stream_result));

  EXPECT_GT(adapter->GetHpackDecoderSizeLimit(), 100);

  // Submit settings, check decoder table size.
  adapter->SubmitSettings({{HEADER_TABLE_SIZE, 100u}});
  EXPECT_GT(adapter->GetHpackDecoderSizeLimit(), 100);

  // Server preface SETTINGS ack
  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x1));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x1, 0));
  // SETTINGS with the new header table size value
  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, 6, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, 6, 0x0, 0));

  // Because the client has not yet seen an ack from the server for the SETTINGS
  // with header table size, it has not applied the new value.
  EXPECT_GT(adapter->GetHpackDecoderSizeLimit(), 100);

  result = adapter->Send();
  EXPECT_EQ(0, result);
  visitor.Clear();

  const std::vector<Header> headers2 = ToHeaders({
      {":method", "GET"},
      {":scheme", "http"},
      {":authority", "example.com"},
      {":path", "/this/is/request/two"},
  });

  const int32_t stream_id2 = adapter->SubmitRequest(headers2, nullptr, nullptr);
  ASSERT_GT(stream_id2, stream_id1);

  EXPECT_CALL(visitor, OnBeforeFrameSent(HEADERS, stream_id2, _, 0x5));
  EXPECT_CALL(visitor, OnFrameSent(HEADERS, stream_id2, _, 0x5, 0));

  result = adapter->Send();
  EXPECT_EQ(0, result);
  visitor.Clear();

  const std::string response_frames =
      TestFrameSequence()
          .Headers(stream_id2,
                   {{":status", "200"},
                    {"server", "my-fake-server"},
                    {"date", "Tue, 6 Apr 2021 12:54:01 GMT"}},
                   /*fin=*/true)
          .Serialize();

  EXPECT_CALL(visitor, OnFrameHeader(stream_id2, _, HEADERS, 5));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(stream_id2));
  EXPECT_CALL(visitor, OnHeaderForStream(stream_id2, _, _)).Times(3);
  EXPECT_CALL(visitor, OnEndHeadersForStream(stream_id2));
  EXPECT_CALL(visitor, OnEndStream(stream_id2));
  EXPECT_CALL(visitor,
              OnCloseStream(stream_id2, Http2ErrorCode::HTTP2_NO_ERROR));

  const int64_t response_result = adapter->ProcessBytes(response_frames);
  EXPECT_EQ(response_frames.size(), static_cast<size_t>(response_result));

  // Still no ack for the outbound settings.
  EXPECT_GT(adapter->GetHpackDecoderSizeLimit(), 100);

  const std::string settings_ack =
      TestFrameSequence().SettingsAck().Serialize();

  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 1));
  EXPECT_CALL(visitor, OnSettingsAck());

  const int64_t ack_result = adapter->ProcessBytes(settings_ack);
  EXPECT_EQ(settings_ack.size(), static_cast<size_t>(ack_result));
  // Ack has finally arrived.
  EXPECT_EQ(adapter->GetHpackDecoderSizeLimit(), 100);
}

// TODO(birenroy): Validate headers and re-enable this test. The library should
// invoke OnErrorDebug() with an error message for the invalid header. The
// library should also invoke OnInvalidFrame() for the invalid HEADERS frame.
TEST(OgHttp2AdapterClientTest, DISABLED_ClientHandlesInvalidTrailers) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kClient};
  auto adapter = OgHttp2Adapter::Create(visitor, options);

  testing::InSequence s;

  const std::vector<Header> headers1 =
      ToHeaders({{":method", "GET"},
                 {":scheme", "http"},
                 {":authority", "example.com"},
                 {":path", "/this/is/request/one"}});

  const char* kSentinel1 = "arbitrary pointer 1";
  const int32_t stream_id1 =
      adapter->SubmitRequest(headers1, nullptr, const_cast<char*>(kSentinel1));
  ASSERT_GT(stream_id1, 0);
  QUICHE_LOG(INFO) << "Created stream: " << stream_id1;

  EXPECT_CALL(visitor, OnBeforeFrameSent(HEADERS, stream_id1, _, 0x5));
  EXPECT_CALL(visitor, OnFrameSent(HEADERS, stream_id1, _, 0x5, 0));

  int result = adapter->Send();
  EXPECT_EQ(0, result);
  absl::string_view data = visitor.data();
  EXPECT_THAT(data, testing::StartsWith(spdy::kHttp2ConnectionHeaderPrefix));
  data.remove_prefix(strlen(spdy::kHttp2ConnectionHeaderPrefix));
  EXPECT_THAT(data,
              EqualsFrames({SpdyFrameType::SETTINGS, SpdyFrameType::HEADERS}));
  visitor.Clear();

  const std::string stream_frames =
      TestFrameSequence()
          .ServerPreface()
          .Headers(1,
                   {{":status", "200"},
                    {"server", "my-fake-server"},
                    {"date", "Tue, 6 Apr 2021 12:54:01 GMT"}},
                   /*fin=*/false)
          .Data(1, "This is the response body.")
          .Headers(1, {{":bad-status", "9000"}},
                   /*fin=*/true)
          .Serialize();

  // Server preface (empty SETTINGS)
  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor, OnSettingsEnd());

  EXPECT_CALL(visitor, OnFrameHeader(1, _, HEADERS, 4));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(1));
  EXPECT_CALL(visitor, OnHeaderForStream(1, ":status", "200"));
  EXPECT_CALL(visitor, OnHeaderForStream(1, "server", "my-fake-server"));
  EXPECT_CALL(visitor,
              OnHeaderForStream(1, "date", "Tue, 6 Apr 2021 12:54:01 GMT"));
  EXPECT_CALL(visitor, OnEndHeadersForStream(1));
  EXPECT_CALL(visitor, OnFrameHeader(1, 26, DATA, 0));
  EXPECT_CALL(visitor, OnBeginDataForStream(1, 26));
  EXPECT_CALL(visitor, OnDataForStream(1, "This is the response body."));
  EXPECT_CALL(visitor, OnFrameHeader(1, _, HEADERS, 5));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(1));

  // Bad status trailer will cause a PROTOCOL_ERROR. The header is never
  // delivered in an OnHeaderForStream callback.

  const int64_t stream_result = adapter->ProcessBytes(stream_frames);
  EXPECT_EQ(stream_frames.size(), static_cast<size_t>(stream_result));

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, 0, 0x1));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, 0, 0x1, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(RST_STREAM, stream_id1, 4, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(RST_STREAM, stream_id1, 4, 0x0, 1));
  EXPECT_CALL(visitor, OnCloseStream(1, Http2ErrorCode::PROTOCOL_ERROR));

  EXPECT_TRUE(adapter->want_write());
  result = adapter->Send();
  EXPECT_EQ(0, result);
  EXPECT_THAT(visitor.data(), EqualsFrames({SpdyFrameType::SETTINGS,
                                            SpdyFrameType::RST_STREAM}));
}

TEST(OgHttp2AdapterClientTest, ClientStartsShutdown) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kClient};
  auto adapter = OgHttp2Adapter::Create(visitor, options);

  EXPECT_FALSE(adapter->want_write());

  // No-op (except for logging) for a client implementation.
  adapter->SubmitShutdownNotice();
  EXPECT_FALSE(adapter->want_write());

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));

  int result = adapter->Send();
  EXPECT_EQ(0, result);

  absl::string_view serialized = visitor.data();
  EXPECT_THAT(serialized,
              testing::StartsWith(spdy::kHttp2ConnectionHeaderPrefix));
  serialized.remove_prefix(strlen(spdy::kHttp2ConnectionHeaderPrefix));
  EXPECT_THAT(serialized, EqualsFrames({SpdyFrameType::SETTINGS}));
}

TEST(OgHttp2AdapterClientTest, ClientFailsOnGoAway) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kClient};
  auto adapter = OgHttp2Adapter::Create(visitor, options);

  testing::InSequence s;

  const std::vector<Header> headers1 =
      ToHeaders({{":method", "GET"},
                 {":scheme", "http"},
                 {":authority", "example.com"},
                 {":path", "/this/is/request/one"}});

  const char* kSentinel1 = "arbitrary pointer 1";
  const int32_t stream_id1 =
      adapter->SubmitRequest(headers1, nullptr, const_cast<char*>(kSentinel1));
  ASSERT_GT(stream_id1, 0);
  QUICHE_LOG(INFO) << "Created stream: " << stream_id1;

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(HEADERS, stream_id1, _, 0x5));
  EXPECT_CALL(visitor, OnFrameSent(HEADERS, stream_id1, _, 0x5, 0));

  int result = adapter->Send();
  EXPECT_EQ(0, result);
  absl::string_view data = visitor.data();
  EXPECT_THAT(data, testing::StartsWith(spdy::kHttp2ConnectionHeaderPrefix));
  data.remove_prefix(strlen(spdy::kHttp2ConnectionHeaderPrefix));
  EXPECT_THAT(data,
              EqualsFrames({SpdyFrameType::SETTINGS, SpdyFrameType::HEADERS}));
  visitor.Clear();

  const std::string stream_frames =
      TestFrameSequence()
          .ServerPreface()
          .Headers(1,
                   {{":status", "200"},
                    {"server", "my-fake-server"},
                    {"date", "Tue, 6 Apr 2021 12:54:01 GMT"}},
                   /*fin=*/false)
          .GoAway(1, Http2ErrorCode::INTERNAL_ERROR, "indigestion")
          .Data(1, "This is the response body.")
          .Serialize();

  // Server preface (empty SETTINGS)
  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor, OnSettingsEnd());

  EXPECT_CALL(visitor, OnFrameHeader(1, _, HEADERS, 4));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(1));
  EXPECT_CALL(visitor, OnHeaderForStream(1, ":status", "200"));
  EXPECT_CALL(visitor, OnHeaderForStream(1, "server", "my-fake-server"));
  EXPECT_CALL(visitor,
              OnHeaderForStream(1, "date", "Tue, 6 Apr 2021 12:54:01 GMT"));
  EXPECT_CALL(visitor, OnEndHeadersForStream(1));
  EXPECT_CALL(visitor, OnFrameHeader(0, _, GOAWAY, 0));
  // TODO(birenroy): Pass the GOAWAY opaque data through the oghttp2 stack.
  EXPECT_CALL(visitor, OnGoAway(1, Http2ErrorCode::INTERNAL_ERROR, ""))
      .WillOnce(testing::Return(false));
  EXPECT_CALL(visitor, OnConnectionError(ConnectionError::kParseError));

  const int64_t stream_result = adapter->ProcessBytes(stream_frames);
  EXPECT_LT(stream_result, 0);

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, 0, 0x1));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, 0, 0x1, 0));

  EXPECT_TRUE(adapter->want_write());
  result = adapter->Send();
  EXPECT_EQ(0, result);
  EXPECT_THAT(visitor.data(), EqualsFrames({SpdyFrameType::SETTINGS}));
}

TEST(OgHttp2AdapterClientTest, ClientRejects101Response) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kClient};
  auto adapter = OgHttp2Adapter::Create(visitor, options);

  testing::InSequence s;

  const std::vector<Header> headers1 =
      ToHeaders({{":method", "GET"},
                 {":scheme", "http"},
                 {":authority", "example.com"},
                 {":path", "/this/is/request/one"},
                 {"upgrade", "new-protocol"}});

  const int32_t stream_id1 = adapter->SubmitRequest(headers1, nullptr, nullptr);
  ASSERT_GT(stream_id1, 0);

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(HEADERS, stream_id1, _, 0x5));
  EXPECT_CALL(visitor, OnFrameSent(HEADERS, stream_id1, _, 0x5, 0));

  int result = adapter->Send();
  EXPECT_EQ(0, result);
  absl::string_view data = visitor.data();
  EXPECT_THAT(data, testing::StartsWith(spdy::kHttp2ConnectionHeaderPrefix));
  data.remove_prefix(strlen(spdy::kHttp2ConnectionHeaderPrefix));
  EXPECT_THAT(data,
              EqualsFrames({SpdyFrameType::SETTINGS, SpdyFrameType::HEADERS}));
  visitor.Clear();

  const std::string stream_frames =
      TestFrameSequence()
          .ServerPreface()
          .Headers(1,
                   {{":status", "101"},
                    {"server", "my-fake-server"},
                    {"date", "Tue, 6 Apr 2021 12:54:01 GMT"}},
                   /*fin=*/false)
          .Serialize();

  // Server preface (empty SETTINGS)
  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor, OnSettingsEnd());

  EXPECT_CALL(visitor, OnFrameHeader(1, _, HEADERS, 4));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(1));
  EXPECT_CALL(
      visitor,
      OnInvalidFrame(1, Http2VisitorInterface::InvalidFrameError::kHttpHeader));

  const int64_t stream_result = adapter->ProcessBytes(stream_frames);
  EXPECT_EQ(static_cast<int64_t>(stream_frames.size()), stream_result);

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, 0, 0x1));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, 0, 0x1, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(RST_STREAM, 1, 4, 0x0));
  EXPECT_CALL(
      visitor,
      OnFrameSent(RST_STREAM, 1, 4, 0x0,
                  static_cast<uint32_t>(Http2ErrorCode::PROTOCOL_ERROR)));
  EXPECT_CALL(visitor, OnCloseStream(1, Http2ErrorCode::HTTP2_NO_ERROR));

  EXPECT_TRUE(adapter->want_write());
  result = adapter->Send();
  EXPECT_EQ(0, result);
  EXPECT_THAT(visitor.data(), EqualsFrames({SpdyFrameType::SETTINGS,
                                            SpdyFrameType::RST_STREAM}));
}

TEST(OgHttp2AdapterClientTest, ClientObeysMaxConcurrentStreams) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kClient};
  auto adapter = OgHttp2Adapter::Create(visitor, options);

  EXPECT_FALSE(adapter->want_write());

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));

  // Even though the user has not queued any frames for the session, it should
  // still send the connection preface.
  int result = adapter->Send();
  EXPECT_EQ(0, result);
  absl::string_view serialized = visitor.data();
  EXPECT_THAT(serialized,
              testing::StartsWith(spdy::kHttp2ConnectionHeaderPrefix));
  serialized.remove_prefix(strlen(spdy::kHttp2ConnectionHeaderPrefix));
  // Initial SETTINGS.
  EXPECT_THAT(serialized, EqualsFrames({SpdyFrameType::SETTINGS}));
  visitor.Clear();

  const std::string initial_frames =
      TestFrameSequence()
          .ServerPreface({{.id = MAX_CONCURRENT_STREAMS, .value = 1}})
          .Serialize();
  testing::InSequence s;

  // Server preface (SETTINGS with MAX_CONCURRENT_STREAMS)
  EXPECT_CALL(visitor, OnFrameHeader(0, 6, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor, OnSetting);
  // TODO(diannahu): Remove this duplicate call with a separate
  // ExtensionVisitorInterface implementation.
  EXPECT_CALL(visitor, OnSetting);
  EXPECT_CALL(visitor, OnSettingsEnd());

  const int64_t initial_result = adapter->ProcessBytes(initial_frames);
  EXPECT_EQ(initial_frames.size(), static_cast<size_t>(initial_result));

  // Session will want to write a SETTINGS ack.
  EXPECT_TRUE(adapter->want_write());

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x1));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x1, 0));

  result = adapter->Send();
  EXPECT_EQ(0, result);
  EXPECT_THAT(visitor.data(), EqualsFrames({SpdyFrameType::SETTINGS}));
  visitor.Clear();

  const std::string kBody = "This is an example request body.";
  auto body1 = absl::make_unique<TestDataFrameSource>(visitor, true);
  body1->AppendPayload(kBody);
  body1->EndData();
  const int stream_id =
      adapter->SubmitRequest(ToHeaders({{":method", "POST"},
                                        {":scheme", "http"},
                                        {":authority", "example.com"},
                                        {":path", "/this/is/request/one"}}),
                             std::move(body1), nullptr);
  EXPECT_GT(stream_id, 0);
  EXPECT_TRUE(adapter->want_write());

  EXPECT_CALL(visitor, OnBeforeFrameSent(HEADERS, stream_id, _, 0x4));
  EXPECT_CALL(visitor, OnFrameSent(HEADERS, stream_id, _, 0x4, 0));
  EXPECT_CALL(visitor, OnFrameSent(DATA, stream_id, _, 0x1, 0));

  result = adapter->Send();
  EXPECT_EQ(0, result);
  EXPECT_THAT(visitor.data(),
              EqualsFrames({SpdyFrameType::HEADERS, SpdyFrameType::DATA}));
  EXPECT_THAT(visitor.data(), testing::HasSubstr(kBody));
  visitor.Clear();
  EXPECT_FALSE(adapter->want_write());

  const int next_stream_id =
      adapter->SubmitRequest(ToHeaders({{":method", "POST"},
                                        {":scheme", "http"},
                                        {":authority", "example.com"},
                                        {":path", "/this/is/request/two"}}),
                             nullptr, nullptr);

  // A new pending stream is created, but because of MAX_CONCURRENT_STREAMS, the
  // session should not want to write it at the moment.
  EXPECT_GT(next_stream_id, stream_id);
  EXPECT_FALSE(adapter->want_write());

  const std::string stream_frames =
      TestFrameSequence()
          .Headers(stream_id,
                   {{":status", "200"},
                    {"server", "my-fake-server"},
                    {"date", "Tue, 6 Apr 2021 12:54:01 GMT"}},
                   /*fin=*/false)
          .Data(stream_id, "This is the response body.", /*fin=*/true)
          .Serialize();

  EXPECT_CALL(visitor, OnFrameHeader(stream_id, _, HEADERS, 4));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(stream_id));
  EXPECT_CALL(visitor, OnHeaderForStream(stream_id, ":status", "200"));
  EXPECT_CALL(visitor,
              OnHeaderForStream(stream_id, "server", "my-fake-server"));
  EXPECT_CALL(visitor, OnHeaderForStream(stream_id, "date",
                                         "Tue, 6 Apr 2021 12:54:01 GMT"));
  EXPECT_CALL(visitor, OnEndHeadersForStream(stream_id));
  EXPECT_CALL(visitor, OnFrameHeader(stream_id, 26, DATA, 0x1));
  EXPECT_CALL(visitor, OnBeginDataForStream(stream_id, 26));
  EXPECT_CALL(visitor,
              OnDataForStream(stream_id, "This is the response body."));
  EXPECT_CALL(visitor, OnEndStream(stream_id));
  EXPECT_CALL(visitor,
              OnCloseStream(stream_id, Http2ErrorCode::HTTP2_NO_ERROR));

  // The first stream should close, which should make the session want to write
  // the next stream.
  const int64_t stream_result = adapter->ProcessBytes(stream_frames);
  EXPECT_EQ(stream_frames.size(), static_cast<size_t>(stream_result));
  EXPECT_TRUE(adapter->want_write());

  EXPECT_CALL(visitor, OnBeforeFrameSent(HEADERS, next_stream_id, _, 0x5));
  EXPECT_CALL(visitor, OnFrameSent(HEADERS, next_stream_id, _, 0x5, 0));

  result = adapter->Send();
  EXPECT_EQ(0, result);

  EXPECT_THAT(visitor.data(), EqualsFrames({SpdyFrameType::HEADERS}));
  visitor.Clear();
  EXPECT_FALSE(adapter->want_write());
}

TEST(OgHttp2AdapterClientTest, ClientReceivesInitialWindowSetting) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kClient};
  auto adapter = OgHttp2Adapter::Create(visitor, options);

  const std::string initial_frames =
      TestFrameSequence()
          .Settings({{INITIAL_WINDOW_SIZE, 80000u}})
          .WindowUpdate(0, 65536)
          .Serialize();
  // Server preface (SETTINGS with INITIAL_STREAM_WINDOW)
  EXPECT_CALL(visitor, OnFrameHeader(0, 6, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  // TODO(diannahu): Remove the duplicate call with a separate
  // ExtensionVisitorInterface implementation.
  EXPECT_CALL(visitor, OnSetting(Http2Setting{INITIAL_WINDOW_SIZE, 80000u}))
      .Times(2);
  EXPECT_CALL(visitor, OnSettingsEnd());
  EXPECT_CALL(visitor, OnFrameHeader(0, 4, WINDOW_UPDATE, 0));
  EXPECT_CALL(visitor, OnWindowUpdate(0, 65536));

  const int64_t initial_result = adapter->ProcessBytes(initial_frames);
  EXPECT_EQ(initial_frames.size(), static_cast<size_t>(initial_result));

  // Session will want to write a SETTINGS ack.
  EXPECT_TRUE(adapter->want_write());

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x1));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x1, 0));

  int64_t result = adapter->Send();
  EXPECT_EQ(0, result);
  absl::string_view serialized = visitor.data();
  EXPECT_THAT(serialized,
              testing::StartsWith(spdy::kHttp2ConnectionHeaderPrefix));
  serialized.remove_prefix(strlen(spdy::kHttp2ConnectionHeaderPrefix));
  EXPECT_THAT(serialized,
              EqualsFrames({SpdyFrameType::SETTINGS, SpdyFrameType::SETTINGS}));
  visitor.Clear();

  const std::string kLongBody = std::string(81000, 'c');
  auto body1 = absl::make_unique<TestDataFrameSource>(visitor, true);
  body1->AppendPayload(kLongBody);
  body1->EndData();
  const int stream_id =
      adapter->SubmitRequest(ToHeaders({{":method", "POST"},
                                        {":scheme", "http"},
                                        {":authority", "example.com"},
                                        {":path", "/this/is/request/one"}}),
                             std::move(body1), nullptr);
  EXPECT_GT(stream_id, 0);
  EXPECT_TRUE(adapter->want_write());

  EXPECT_CALL(visitor, OnBeforeFrameSent(HEADERS, stream_id, _, 0x4));
  EXPECT_CALL(visitor, OnFrameSent(HEADERS, stream_id, _, 0x4, 0));
  // The client can send more than 4 frames (65536 bytes) of data.
  EXPECT_CALL(visitor, OnFrameSent(DATA, stream_id, 16384, 0x0, 0)).Times(4);
  EXPECT_CALL(visitor, OnFrameSent(DATA, stream_id, 14464, 0x0, 0));

  result = adapter->Send();
  EXPECT_EQ(0, result);
  EXPECT_THAT(visitor.data(),
              EqualsFrames({SpdyFrameType::HEADERS, SpdyFrameType::DATA,
                            SpdyFrameType::DATA, SpdyFrameType::DATA,
                            SpdyFrameType::DATA, SpdyFrameType::DATA}));
}

TEST(OgHttp2AdapterClientTest,
     ClientReceivesInitialWindowSettingAfterStreamStart) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kClient};
  auto adapter = OgHttp2Adapter::Create(visitor, options);

  const std::string initial_frames =
      TestFrameSequence().ServerPreface().WindowUpdate(0, 65536).Serialize();
  // Server preface (empty SETTINGS)
  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor, OnSettingsEnd());
  EXPECT_CALL(visitor, OnFrameHeader(0, 4, WINDOW_UPDATE, 0));
  EXPECT_CALL(visitor, OnWindowUpdate(0, 65536));

  const int64_t initial_result = adapter->ProcessBytes(initial_frames);
  EXPECT_EQ(initial_frames.size(), static_cast<size_t>(initial_result));

  // Session will want to write a SETTINGS ack.
  EXPECT_TRUE(adapter->want_write());

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x1));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x1, 0));

  int64_t result = adapter->Send();
  EXPECT_EQ(0, result);
  visitor.Clear();

  const std::string kLongBody = std::string(81000, 'c');
  auto body1 = absl::make_unique<TestDataFrameSource>(visitor, true);
  body1->AppendPayload(kLongBody);
  body1->EndData();
  const int stream_id =
      adapter->SubmitRequest(ToHeaders({{":method", "POST"},
                                        {":scheme", "http"},
                                        {":authority", "example.com"},
                                        {":path", "/this/is/request/one"}}),
                             std::move(body1), nullptr);
  EXPECT_GT(stream_id, 0);
  EXPECT_TRUE(adapter->want_write());

  EXPECT_CALL(visitor, OnBeforeFrameSent(HEADERS, stream_id, _, 0x4));
  EXPECT_CALL(visitor, OnFrameSent(HEADERS, stream_id, _, 0x4, 0));
  // The client can only send 65535 bytes of data, as the stream window has not
  // yet been increased.
  EXPECT_CALL(visitor, OnFrameSent(DATA, stream_id, 16384, 0x0, 0)).Times(3);
  EXPECT_CALL(visitor, OnFrameSent(DATA, stream_id, 16383, 0x0, 0));

  result = adapter->Send();
  EXPECT_EQ(0, result);
  EXPECT_THAT(visitor.data(),
              EqualsFrames({SpdyFrameType::HEADERS, SpdyFrameType::DATA,
                            SpdyFrameType::DATA, SpdyFrameType::DATA,
                            SpdyFrameType::DATA}));
  visitor.Clear();

  // Can't write any more due to flow control.
  EXPECT_FALSE(adapter->want_write());

  const std::string settings_frame =
      TestFrameSequence().Settings({{INITIAL_WINDOW_SIZE, 80000u}}).Serialize();
  // SETTINGS with INITIAL_STREAM_WINDOW
  EXPECT_CALL(visitor, OnFrameHeader(0, 6, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  // TODO(diannahu): Remove the duplicate call with a separate
  // ExtensionVisitorInterface implementation.
  EXPECT_CALL(visitor, OnSetting(Http2Setting{INITIAL_WINDOW_SIZE, 80000u}))
      .Times(2);
  EXPECT_CALL(visitor, OnSettingsEnd());

  const int64_t settings_result = adapter->ProcessBytes(settings_frame);
  EXPECT_EQ(settings_frame.size(), static_cast<size_t>(settings_result));

  EXPECT_TRUE(adapter->want_write());

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x1));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x1, 0));
  // The client can write more after receiving the INITIAL_WINDOW_SIZE setting.
  EXPECT_CALL(visitor, OnFrameSent(DATA, stream_id, 14465, 0x0, 0));

  result = adapter->Send();
  EXPECT_EQ(0, result);
  EXPECT_THAT(visitor.data(),
              EqualsFrames({SpdyFrameType::SETTINGS, SpdyFrameType::DATA}));
}

TEST(OgHttp2AdapterClientTest, InvalidInitialWindowSetting) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kClient};
  auto adapter = OgHttp2Adapter::Create(visitor, options);

  const uint32_t kTooLargeInitialWindow = 1u << 31;
  const std::string initial_frames =
      TestFrameSequence()
          .Settings({{INITIAL_WINDOW_SIZE, kTooLargeInitialWindow}})
          .Serialize();
  // Server preface (SETTINGS with INITIAL_STREAM_WINDOW)
  EXPECT_CALL(visitor, OnFrameHeader(0, 6, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  // TODO(diannahu): Remove the duplicate call with a separate
  // ExtensionVisitorInterface implementation.
  EXPECT_CALL(
      visitor,
      OnInvalidFrame(0, Http2VisitorInterface::InvalidFrameError::kFlowControl))
      .Times(2);
  EXPECT_CALL(visitor,
              OnConnectionError(
                  Http2VisitorInterface::ConnectionError::kFlowControlError));

  const int64_t initial_result = adapter->ProcessBytes(initial_frames);
  EXPECT_EQ(initial_frames.size(), static_cast<size_t>(initial_result));

  // Session will want to write a GOAWAY.
  EXPECT_TRUE(adapter->want_write());

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x1));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x1, 0));

  int64_t result = adapter->Send();
  EXPECT_EQ(0, result);
  absl::string_view serialized = visitor.data();
  EXPECT_THAT(serialized,
              testing::StartsWith(spdy::kHttp2ConnectionHeaderPrefix));
  serialized.remove_prefix(strlen(spdy::kHttp2ConnectionHeaderPrefix));
  EXPECT_THAT(serialized,
              EqualsFrames({SpdyFrameType::SETTINGS, SpdyFrameType::SETTINGS}));
  visitor.Clear();
}

TEST(OggHttp2AdapterClientTest, InitialWindowSettingCausesOverflow) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kClient};
  auto adapter = OgHttp2Adapter::Create(visitor, options);

  testing::InSequence s;

  const std::vector<Header> headers =
      ToHeaders({{":method", "GET"},
                 {":scheme", "http"},
                 {":authority", "example.com"},
                 {":path", "/this/is/request/one"}});
  const int32_t stream_id = adapter->SubmitRequest(headers, nullptr, nullptr);
  ASSERT_GT(stream_id, 0);

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(HEADERS, stream_id, _, 0x5));
  EXPECT_CALL(visitor, OnFrameSent(HEADERS, stream_id, _, 0x5, 0));
  int64_t write_result = adapter->Send();
  EXPECT_EQ(0, write_result);
  absl::string_view data = visitor.data();
  EXPECT_THAT(data, testing::StartsWith(spdy::kHttp2ConnectionHeaderPrefix));
  data.remove_prefix(strlen(spdy::kHttp2ConnectionHeaderPrefix));
  EXPECT_THAT(data,
              EqualsFrames({SpdyFrameType::SETTINGS, SpdyFrameType::HEADERS}));
  visitor.Clear();

  const uint32_t kLargeInitialWindow = (1u << 31) - 1;
  const std::string frames =
      TestFrameSequence()
          .ServerPreface()
          .Headers(stream_id, {{":status", "200"}}, /*fin=*/false)
          .WindowUpdate(stream_id, 65536u)
          .Settings({{INITIAL_WINDOW_SIZE, kLargeInitialWindow}})
          .Serialize();

  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor, OnSettingsEnd());

  EXPECT_CALL(visitor, OnFrameHeader(stream_id, _, HEADERS, 0x4));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(stream_id));
  EXPECT_CALL(visitor, OnHeaderForStream(stream_id, ":status", "200"));
  EXPECT_CALL(visitor, OnEndHeadersForStream(stream_id));

  EXPECT_CALL(visitor, OnFrameHeader(stream_id, 4, WINDOW_UPDATE, 0x0));
  EXPECT_CALL(visitor, OnWindowUpdate(stream_id, 65536));

  EXPECT_CALL(visitor, OnFrameHeader(0, 6, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor,
              OnSetting(Http2Setting{INITIAL_WINDOW_SIZE, kLargeInitialWindow}))
      .Times(2);
  EXPECT_CALL(visitor, OnSettingsEnd());

  const int64_t read_result = adapter->ProcessBytes(frames);
  EXPECT_EQ(static_cast<size_t>(read_result), frames.size());
  EXPECT_TRUE(adapter->want_write());

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, 0, 0x1));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, 0, 0x1, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, 0, 0x1));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, 0, 0x1, 0));

  // The stream window update plus the SETTINGS frame with INITIAL_WINDOW_SIZE
  // pushes the stream's flow control window outside of the acceptable range.
  EXPECT_CALL(visitor, OnBeforeFrameSent(RST_STREAM, stream_id, 4, 0x0));
  EXPECT_CALL(
      visitor,
      OnFrameSent(RST_STREAM, stream_id, 4, 0x0,
                  static_cast<int>(Http2ErrorCode::FLOW_CONTROL_ERROR)));
  EXPECT_CALL(visitor,
              OnCloseStream(stream_id, Http2ErrorCode::HTTP2_NO_ERROR));

  int result = adapter->Send();
  EXPECT_EQ(0, result);
  EXPECT_THAT(visitor.data(),
              EqualsFrames({SpdyFrameType::SETTINGS, SpdyFrameType::SETTINGS,
                            SpdyFrameType::RST_STREAM}));
}

TEST(OgHttp2AdapterClientTest, FailureSendingConnectionPreface) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kClient};
  auto adapter = OgHttp2Adapter::Create(visitor, options);

  visitor.set_has_write_error();
  EXPECT_CALL(visitor, OnConnectionError(ConnectionError::kSendError));

  int result = adapter->Send();
  EXPECT_LT(result, 0);
}

TEST(OgHttp2AdapterClientTest, ClientForbidsPushPromise) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kClient};
  auto adapter = OgHttp2Adapter::Create(visitor, options);

  testing::InSequence s;

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));

  int write_result = adapter->Send();
  EXPECT_EQ(0, write_result);
  absl::string_view data = visitor.data();
  EXPECT_THAT(data, testing::StartsWith(spdy::kHttp2ConnectionHeaderPrefix));
  data.remove_prefix(strlen(spdy::kHttp2ConnectionHeaderPrefix));
  EXPECT_THAT(data, EqualsFrames({SpdyFrameType::SETTINGS}));

  visitor.Clear();

  const std::vector<Header> headers =
      ToHeaders({{":method", "GET"},
                 {":scheme", "http"},
                 {":authority", "example.com"},
                 {":path", "/this/is/request/one"}});
  const int32_t stream_id = adapter->SubmitRequest(headers, nullptr, nullptr);
  ASSERT_GT(stream_id, 0);
  EXPECT_CALL(visitor, OnBeforeFrameSent(HEADERS, stream_id, _, 0x5));
  EXPECT_CALL(visitor, OnFrameSent(HEADERS, stream_id, _, 0x5, 0));
  write_result = adapter->Send();
  EXPECT_EQ(0, write_result);
  EXPECT_THAT(visitor.data(), EqualsFrames({SpdyFrameType::HEADERS}));
  visitor.Clear();

  const std::vector<Header> push_headers =
      ToHeaders({{":method", "GET"},
                 {":scheme", "http"},
                 {":authority", "example.com"},
                 {":path", "/this/is/request/push"}});
  const std::string frames = TestFrameSequence()
                                 .ServerPreface()
                                 .SettingsAck()
                                 .PushPromise(stream_id, 2, push_headers)
                                 .Serialize();

  // Server preface (empty SETTINGS)
  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor, OnSettingsEnd());

  // SETTINGS ack (to acknowledge PUSH_ENABLED=0, though this is not explicitly
  // required for OgHttp2: should it be?)
  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0x1));
  EXPECT_CALL(visitor, OnSettingsAck);

  // The PUSH_PROMISE is treated as an invalid frame.
  EXPECT_CALL(visitor, OnFrameHeader(stream_id, _, PUSH_PROMISE, _));
  EXPECT_CALL(visitor, OnConnectionError(ConnectionError::kInvalidPushPromise));

  const int64_t read_result = adapter->ProcessBytes(frames);
  EXPECT_EQ(static_cast<size_t>(read_result), frames.size());

  EXPECT_TRUE(adapter->want_write());

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x1));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x1, 0));

  int result = adapter->Send();
  EXPECT_EQ(0, result);
  // SETTINGS ack.
  EXPECT_THAT(visitor.data(), EqualsFrames({SpdyFrameType::SETTINGS}));
}

TEST(OgHttp2AdapterClientTest, ClientForbidsPushStream) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kClient};
  auto adapter = OgHttp2Adapter::Create(visitor, options);

  testing::InSequence s;

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));

  int write_result = adapter->Send();
  EXPECT_EQ(0, write_result);
  absl::string_view data = visitor.data();
  EXPECT_THAT(data, testing::StartsWith(spdy::kHttp2ConnectionHeaderPrefix));
  data.remove_prefix(strlen(spdy::kHttp2ConnectionHeaderPrefix));
  EXPECT_THAT(data, EqualsFrames({SpdyFrameType::SETTINGS}));

  visitor.Clear();

  const std::vector<Header> headers =
      ToHeaders({{":method", "GET"},
                 {":scheme", "http"},
                 {":authority", "example.com"},
                 {":path", "/this/is/request/one"}});
  const int32_t stream_id = adapter->SubmitRequest(headers, nullptr, nullptr);
  ASSERT_GT(stream_id, 0);
  EXPECT_CALL(visitor, OnBeforeFrameSent(HEADERS, stream_id, _, 0x5));
  EXPECT_CALL(visitor, OnFrameSent(HEADERS, stream_id, _, 0x5, 0));
  write_result = adapter->Send();
  EXPECT_EQ(0, write_result);
  EXPECT_THAT(visitor.data(), EqualsFrames({SpdyFrameType::HEADERS}));
  visitor.Clear();

  const std::string frames =
      TestFrameSequence()
          .ServerPreface()
          .SettingsAck()
          .Headers(2,
                   {{":status", "200"},
                    {"server", "my-fake-server"},
                    {"date", "Tue, 6 Apr 2021 12:54:01 GMT"}},
                   /*fin=*/true)
          .Serialize();

  // Server preface (empty SETTINGS)
  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor, OnSettingsEnd());

  // SETTINGS ack (to acknowledge PUSH_ENABLED=0, though this is not explicitly
  // required for OgHttp2: should it be?)
  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0x1));
  EXPECT_CALL(visitor, OnSettingsAck);

  // The push HEADERS are invalid.
  EXPECT_CALL(visitor, OnFrameHeader(2, _, HEADERS, _));
  EXPECT_CALL(visitor, OnConnectionError(ConnectionError::kInvalidNewStreamId));

  const int64_t read_result = adapter->ProcessBytes(frames);
  EXPECT_EQ(static_cast<size_t>(read_result), frames.size());

  EXPECT_TRUE(adapter->want_write());

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x1));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x1, 0));

  int result = adapter->Send();
  EXPECT_EQ(0, result);
  // SETTINGS ack.
  EXPECT_THAT(visitor.data(), EqualsFrames({SpdyFrameType::SETTINGS}));
}

TEST(OgHttp2AdapterClientTest, ClientReceivesDataOnClosedStream) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kClient};
  auto adapter = OgHttp2Adapter::Create(visitor, options);

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  int result = adapter->Send();
  EXPECT_EQ(0, result);
  absl::string_view data = visitor.data();
  EXPECT_THAT(data, testing::StartsWith(spdy::kHttp2ConnectionHeaderPrefix));
  data.remove_prefix(strlen(spdy::kHttp2ConnectionHeaderPrefix));
  EXPECT_THAT(data, EqualsFrames({SpdyFrameType::SETTINGS}));
  visitor.Clear();

  const std::string initial_frames =
      TestFrameSequence().ServerPreface().Serialize();
  testing::InSequence s;

  // Server preface (empty SETTINGS)
  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor, OnSettingsEnd());

  const int64_t initial_result = adapter->ProcessBytes(initial_frames);
  EXPECT_EQ(initial_frames.size(), static_cast<size_t>(initial_result));

  // Client SETTINGS ack
  EXPECT_TRUE(adapter->want_write());
  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, 0, 0x1));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, 0, 0x1, 0));

  result = adapter->Send();
  EXPECT_EQ(0, result);
  EXPECT_THAT(visitor.data(), EqualsFrames({SpdyFrameType::SETTINGS}));
  visitor.Clear();

  // Let the client open a stream with a request.
  int stream_id =
      adapter->SubmitRequest(ToHeaders({{":method", "GET"},
                                        {":scheme", "http"},
                                        {":authority", "example.com"},
                                        {":path", "/this/is/request/one"}}),
                             nullptr, nullptr);
  EXPECT_GT(stream_id, 0);

  EXPECT_TRUE(adapter->want_write());
  EXPECT_CALL(visitor, OnBeforeFrameSent(HEADERS, stream_id, _, 0x5));
  EXPECT_CALL(visitor, OnFrameSent(HEADERS, stream_id, _, 0x5, 0));

  result = adapter->Send();
  EXPECT_EQ(0, result);
  EXPECT_THAT(visitor.data(), EqualsFrames({SpdyFrameType::HEADERS}));
  visitor.Clear();

  // Let the client RST_STREAM the stream it opened.
  adapter->SubmitRst(stream_id, Http2ErrorCode::CANCEL);
  EXPECT_TRUE(adapter->want_write());
  EXPECT_CALL(visitor, OnBeforeFrameSent(RST_STREAM, stream_id, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(RST_STREAM, stream_id, _, 0x0,
                                   static_cast<int>(Http2ErrorCode::CANCEL)));
  EXPECT_CALL(visitor,
              OnCloseStream(stream_id, Http2ErrorCode::HTTP2_NO_ERROR));

  result = adapter->Send();
  EXPECT_EQ(0, result);
  EXPECT_THAT(visitor.data(), EqualsFrames({SpdyFrameType::RST_STREAM}));
  visitor.Clear();

  // Let the server send a response on the stream. (It might not have received
  // the RST_STREAM yet.)
  const std::string response_frames =
      TestFrameSequence()
          .Headers(stream_id,
                   {{":status", "200"},
                    {"server", "my-fake-server"},
                    {"date", "Tue, 6 Apr 2021 12:54:01 GMT"}},
                   /*fin=*/false)
          .Data(stream_id, "This is the response body.", /*fin=*/true)
          .Serialize();

  // The visitor gets notified about the HEADERS frame and DATA frame for the
  // closed stream with no further processing on either frame.
  EXPECT_CALL(visitor, OnFrameHeader(stream_id, _, HEADERS, 0x4));
  EXPECT_CALL(visitor, OnFrameHeader(stream_id, _, DATA, 0x1));

  const int64_t response_result = adapter->ProcessBytes(response_frames);
  EXPECT_EQ(response_frames.size(), static_cast<size_t>(response_result));

  EXPECT_FALSE(adapter->want_write());
}

TEST(OgHttp2AdapterClientTest, ClientEncountersFlowControlBlock) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kClient};
  auto adapter = OgHttp2Adapter::Create(visitor, options);

  testing::InSequence s;

  const std::vector<Header> headers1 =
      ToHeaders({{":method", "GET"},
                 {":scheme", "http"},
                 {":authority", "example.com"},
                 {":path", "/this/is/request/one"}});

  const std::string kBody = std::string(100 * 1024, 'a');
  auto body1 = absl::make_unique<TestDataFrameSource>(visitor, false);
  body1->AppendPayload(kBody);
  body1->EndData();

  const int32_t stream_id1 =
      adapter->SubmitRequest(headers1, std::move(body1), nullptr);
  ASSERT_GT(stream_id1, 0);

  const std::vector<Header> headers2 =
      ToHeaders({{":method", "GET"},
                 {":scheme", "http"},
                 {":authority", "example.com"},
                 {":path", "/this/is/request/two"}});

  auto body2 = absl::make_unique<TestDataFrameSource>(visitor, false);
  body2->AppendPayload(kBody);
  body2->EndData();

  const int32_t stream_id2 =
      adapter->SubmitRequest(headers2, std::move(body2), nullptr);
  ASSERT_GT(stream_id2, 0);

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(HEADERS, stream_id1, _, 0x4));
  EXPECT_CALL(visitor, OnFrameSent(HEADERS, stream_id1, _, 0x4, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(HEADERS, stream_id2, _, 0x4));
  EXPECT_CALL(visitor, OnFrameSent(HEADERS, stream_id2, _, 0x4, 0));
  // 4 DATA frames should saturate the default 64kB stream/connection flow
  // control window.
  EXPECT_CALL(visitor, OnFrameSent(DATA, stream_id1, _, 0x0, 0)).Times(4);

  int result = adapter->Send();
  EXPECT_EQ(0, result);
  EXPECT_EQ(0, adapter->GetSendWindowSize());

  const std::string stream_frames = TestFrameSequence()
                                        .ServerPreface()
                                        .WindowUpdate(0, 80000)
                                        .WindowUpdate(stream_id1, 20000)
                                        .Serialize();

  // Server preface (empty SETTINGS)
  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor, OnSettingsEnd());

  EXPECT_CALL(visitor, OnFrameHeader(0, 4, WINDOW_UPDATE, 0));
  EXPECT_CALL(visitor, OnWindowUpdate(0, 80000));
  EXPECT_CALL(visitor, OnFrameHeader(1, 4, WINDOW_UPDATE, 0));
  EXPECT_CALL(visitor, OnWindowUpdate(1, 20000));

  const int64_t stream_result = adapter->ProcessBytes(stream_frames);
  EXPECT_EQ(stream_frames.size(), static_cast<size_t>(stream_result));

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x1));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x1, 0));

  EXPECT_CALL(visitor, OnFrameSent(DATA, stream_id2, _, 0x0, 0))
      .Times(testing::AtLeast(1));
  EXPECT_CALL(visitor, OnFrameSent(DATA, stream_id1, _, 0x0, 0))
      .Times(testing::AtLeast(1));

  EXPECT_TRUE(adapter->want_write());
  result = adapter->Send();
  EXPECT_EQ(0, result);
}

TEST(OgHttp2AdapterClientTest, ClientSendsTrailersAfterFlowControlBlock) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kClient};
  auto adapter = OgHttp2Adapter::Create(visitor, options);

  testing::InSequence s;

  const std::vector<Header> headers1 =
      ToHeaders({{":method", "GET"},
                 {":scheme", "http"},
                 {":authority", "example.com"},
                 {":path", "/this/is/request/one"}});

  auto body1 = absl::make_unique<TestDataFrameSource>(visitor, false);
  body1->AppendPayload("Really small body.");
  body1->EndData();

  const int32_t stream_id1 =
      adapter->SubmitRequest(headers1, std::move(body1), nullptr);
  ASSERT_GT(stream_id1, 0);

  const std::vector<Header> headers2 =
      ToHeaders({{":method", "GET"},
                 {":scheme", "http"},
                 {":authority", "example.com"},
                 {":path", "/this/is/request/two"}});

  const std::string kBody = std::string(100 * 1024, 'a');
  auto body2 = absl::make_unique<TestDataFrameSource>(visitor, false);
  body2->AppendPayload(kBody);
  body2->EndData();

  const int32_t stream_id2 =
      adapter->SubmitRequest(headers2, std::move(body2), nullptr);
  ASSERT_GT(stream_id2, 0);

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(HEADERS, stream_id1, _, 0x4));
  EXPECT_CALL(visitor, OnFrameSent(HEADERS, stream_id1, _, 0x4, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(HEADERS, stream_id2, _, 0x4));
  EXPECT_CALL(visitor, OnFrameSent(HEADERS, stream_id2, _, 0x4, 0));
  EXPECT_CALL(visitor, OnFrameSent(DATA, stream_id1, _, 0x0, 0)).Times(1);
  // 4 DATA frames should saturate the default 64kB stream/connection flow
  // control window.
  EXPECT_CALL(visitor, OnFrameSent(DATA, stream_id2, _, 0x0, 0)).Times(4);

  int result = adapter->Send();
  EXPECT_EQ(0, result);
  EXPECT_FALSE(adapter->want_write());
  EXPECT_EQ(0, adapter->GetSendWindowSize());

  const std::vector<Header> trailers1 =
      ToHeaders({{"extra-info", "Trailers are weird but good?"}});
  adapter->SubmitTrailer(stream_id1, trailers1);

  EXPECT_CALL(visitor, OnBeforeFrameSent(HEADERS, stream_id1, _, 0x5));
  EXPECT_CALL(visitor, OnFrameSent(HEADERS, stream_id1, _, 0x5, 0));

  result = adapter->Send();
  EXPECT_EQ(0, result);
}

TEST(OgHttp2AdapterClientTest, ClientSendsMetadataAfterFlowControlBlock) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kClient};
  auto adapter = OgHttp2Adapter::Create(visitor, options);

  testing::InSequence s;

  const std::vector<Header> headers1 =
      ToHeaders({{":method", "GET"},
                 {":scheme", "http"},
                 {":authority", "example.com"},
                 {":path", "/this/is/request/one"}});

  const std::string kBody = std::string(100 * 1024, 'a');
  auto body1 = absl::make_unique<TestDataFrameSource>(visitor, false);
  body1->AppendPayload(kBody);
  body1->EndData();

  const int32_t stream_id1 =
      adapter->SubmitRequest(headers1, std::move(body1), nullptr);
  ASSERT_GT(stream_id1, 0);

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(HEADERS, stream_id1, _, 0x4));
  EXPECT_CALL(visitor, OnFrameSent(HEADERS, stream_id1, _, 0x4, 0));
  // 4 DATA frames should saturate the default 64kB stream/connection flow
  // control window.
  EXPECT_CALL(visitor, OnFrameSent(DATA, stream_id1, _, 0x0, 0)).Times(4);

  int result = adapter->Send();
  EXPECT_EQ(0, result);
  EXPECT_FALSE(adapter->want_write());
  EXPECT_EQ(0, adapter->GetSendWindowSize());

  auto source = absl::make_unique<TestMetadataSource>(ToHeaderBlock(ToHeaders(
      {{"query-cost", "is too darn high"}, {"secret-sauce", "hollandaise"}})));
  adapter->SubmitMetadata(1, 16384u, std::move(source));
  EXPECT_CALL(visitor, OnBeforeFrameSent(kMetadataFrameType, 1, _, 0x4));
  EXPECT_CALL(visitor, OnFrameSent(kMetadataFrameType, 1, _, 0x4, 0));

  result = adapter->Send();
  EXPECT_EQ(0, result);
}

TEST_F(OgHttp2AdapterTest, SubmitMetadata) {
  auto source = absl::make_unique<TestMetadataSource>(ToHeaderBlock(ToHeaders(
      {{"query-cost", "is too darn high"}, {"secret-sauce", "hollandaise"}})));
  adapter_->SubmitMetadata(1, 16384u, std::move(source));
  EXPECT_TRUE(adapter_->want_write());

  EXPECT_CALL(http2_visitor_, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(http2_visitor_, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  EXPECT_CALL(http2_visitor_, OnBeforeFrameSent(kMetadataFrameType, 1, _, 0x4));
  EXPECT_CALL(http2_visitor_, OnFrameSent(kMetadataFrameType, 1, _, 0x4, 0));

  int result = adapter_->Send();
  EXPECT_EQ(0, result);
  EXPECT_THAT(http2_visitor_.data(),
              EqualsFrames({SpdyFrameType::SETTINGS,
                            static_cast<SpdyFrameType>(kMetadataFrameType)}));
  EXPECT_FALSE(adapter_->want_write());
}

TEST_F(OgHttp2AdapterTest, SubmitMetadataMultipleFrames) {
  const auto kLargeValue = std::string(63 * 1024, 'a');
  auto source = absl::make_unique<TestMetadataSource>(
      ToHeaderBlock(ToHeaders({{"large-value", kLargeValue}})));
  adapter_->SubmitMetadata(1, 16384u, std::move(source));
  EXPECT_TRUE(adapter_->want_write());

  testing::InSequence seq;
  EXPECT_CALL(http2_visitor_, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(http2_visitor_, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  EXPECT_CALL(http2_visitor_, OnBeforeFrameSent(kMetadataFrameType, 1, _, 0x0));
  EXPECT_CALL(http2_visitor_, OnFrameSent(kMetadataFrameType, 1, _, 0x0, 0));
  EXPECT_CALL(http2_visitor_, OnBeforeFrameSent(kMetadataFrameType, 1, _, 0x0));
  EXPECT_CALL(http2_visitor_, OnFrameSent(kMetadataFrameType, 1, _, 0x0, 0));
  EXPECT_CALL(http2_visitor_, OnBeforeFrameSent(kMetadataFrameType, 1, _, 0x0));
  EXPECT_CALL(http2_visitor_, OnFrameSent(kMetadataFrameType, 1, _, 0x0, 0));
  EXPECT_CALL(http2_visitor_, OnBeforeFrameSent(kMetadataFrameType, 1, _, 0x4));
  EXPECT_CALL(http2_visitor_, OnFrameSent(kMetadataFrameType, 1, _, 0x4, 0));

  int result = adapter_->Send();
  EXPECT_EQ(0, result);
  absl::string_view serialized = http2_visitor_.data();
  EXPECT_THAT(serialized,
              EqualsFrames({SpdyFrameType::SETTINGS,
                            static_cast<SpdyFrameType>(kMetadataFrameType),
                            static_cast<SpdyFrameType>(kMetadataFrameType),
                            static_cast<SpdyFrameType>(kMetadataFrameType),
                            static_cast<SpdyFrameType>(kMetadataFrameType)}));
  EXPECT_FALSE(adapter_->want_write());
}

TEST_F(OgHttp2AdapterTest, SubmitConnectionMetadata) {
  auto source = absl::make_unique<TestMetadataSource>(ToHeaderBlock(ToHeaders(
      {{"query-cost", "is too darn high"}, {"secret-sauce", "hollandaise"}})));
  adapter_->SubmitMetadata(0, 16384u, std::move(source));
  EXPECT_TRUE(adapter_->want_write());

  EXPECT_CALL(http2_visitor_, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(http2_visitor_, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  EXPECT_CALL(http2_visitor_, OnBeforeFrameSent(kMetadataFrameType, 0, _, 0x4));
  EXPECT_CALL(http2_visitor_, OnFrameSent(kMetadataFrameType, 0, _, 0x4, 0));

  int result = adapter_->Send();
  EXPECT_EQ(0, result);
  EXPECT_THAT(http2_visitor_.data(),
              EqualsFrames({SpdyFrameType::SETTINGS,
                            static_cast<SpdyFrameType>(kMetadataFrameType)}));
  EXPECT_FALSE(adapter_->want_write());
}

TEST_F(OgHttp2AdapterTest, GetSendWindowSize) {
  const int peer_window = adapter_->GetSendWindowSize();
  EXPECT_EQ(peer_window, kInitialFlowControlWindowSize);
}

TEST_F(OgHttp2AdapterTest, MarkDataConsumedForStream) {
  EXPECT_QUICHE_BUG(adapter_->MarkDataConsumedForStream(1, 11),
                    "Stream 1 not found");
}

TEST_F(OgHttp2AdapterTest, TestSerialize) {
  EXPECT_TRUE(adapter_->want_read());
  EXPECT_FALSE(adapter_->want_write());

  adapter_->SubmitSettings(
      {{HEADER_TABLE_SIZE, 128}, {MAX_FRAME_SIZE, 128 << 10}});
  EXPECT_TRUE(adapter_->want_write());

  const Http2StreamId accepted_stream = 3;
  const Http2StreamId rejected_stream = 7;
  adapter_->SubmitPriorityForStream(accepted_stream, 1, 255, true);
  adapter_->SubmitRst(rejected_stream, Http2ErrorCode::CANCEL);
  adapter_->SubmitPing(42);
  adapter_->SubmitGoAway(13, Http2ErrorCode::HTTP2_NO_ERROR, "");
  adapter_->SubmitWindowUpdate(accepted_stream, 127);
  EXPECT_TRUE(adapter_->want_write());

  EXPECT_CALL(http2_visitor_, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(http2_visitor_, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  EXPECT_CALL(http2_visitor_,
              OnBeforeFrameSent(PRIORITY, accepted_stream, _, 0x0));
  EXPECT_CALL(http2_visitor_,
              OnFrameSent(PRIORITY, accepted_stream, _, 0x0, 0));
  EXPECT_CALL(http2_visitor_,
              OnBeforeFrameSent(RST_STREAM, rejected_stream, _, 0x0));
  EXPECT_CALL(http2_visitor_,
              OnFrameSent(RST_STREAM, rejected_stream, _, 0x0, 0x8));
  EXPECT_CALL(http2_visitor_, OnBeforeFrameSent(PING, 0, _, 0x0));
  EXPECT_CALL(http2_visitor_, OnFrameSent(PING, 0, _, 0x0, 0));
  EXPECT_CALL(http2_visitor_, OnBeforeFrameSent(GOAWAY, 0, _, 0x0));
  EXPECT_CALL(http2_visitor_, OnFrameSent(GOAWAY, 0, _, 0x0, 0));
  EXPECT_CALL(http2_visitor_,
              OnBeforeFrameSent(WINDOW_UPDATE, accepted_stream, _, 0x0));
  EXPECT_CALL(http2_visitor_,
              OnFrameSent(WINDOW_UPDATE, accepted_stream, _, 0x0, 0));

  int result = adapter_->Send();
  EXPECT_EQ(0, result);
  EXPECT_THAT(
      http2_visitor_.data(),
      EqualsFrames({SpdyFrameType::SETTINGS, SpdyFrameType::PRIORITY,
                    SpdyFrameType::RST_STREAM, SpdyFrameType::PING,
                    SpdyFrameType::GOAWAY, SpdyFrameType::WINDOW_UPDATE}));
  EXPECT_FALSE(adapter_->want_write());
}

TEST_F(OgHttp2AdapterTest, TestPartialSerialize) {
  EXPECT_FALSE(adapter_->want_write());

  adapter_->SubmitSettings(
      {{HEADER_TABLE_SIZE, 128}, {MAX_FRAME_SIZE, 128 << 10}});
  adapter_->SubmitGoAway(13, Http2ErrorCode::HTTP2_NO_ERROR,
                         "And don't come back!");
  adapter_->SubmitPing(42);
  EXPECT_TRUE(adapter_->want_write());

  http2_visitor_.set_send_limit(20);
  EXPECT_CALL(http2_visitor_, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(http2_visitor_, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  int result = adapter_->Send();
  EXPECT_EQ(0, result);
  EXPECT_TRUE(adapter_->want_write());
  EXPECT_CALL(http2_visitor_, OnBeforeFrameSent(GOAWAY, 0, _, 0x0));
  EXPECT_CALL(http2_visitor_, OnFrameSent(GOAWAY, 0, _, 0x0, 0));
  result = adapter_->Send();
  EXPECT_EQ(0, result);
  EXPECT_TRUE(adapter_->want_write());
  EXPECT_CALL(http2_visitor_, OnBeforeFrameSent(PING, 0, _, 0x0));
  EXPECT_CALL(http2_visitor_, OnFrameSent(PING, 0, _, 0x0, 0));
  result = adapter_->Send();
  EXPECT_EQ(0, result);
  EXPECT_FALSE(adapter_->want_write());
  EXPECT_THAT(http2_visitor_.data(),
              EqualsFrames({SpdyFrameType::SETTINGS, SpdyFrameType::GOAWAY,
                            SpdyFrameType::PING}));
}

TEST_F(OgHttp2AdapterTest, ConnectionErrorOnControlFrameSent) {
  const std::string frames =
      TestFrameSequence().ClientPreface().Ping(42).Serialize();
  testing::InSequence s;

  // Client preface (empty SETTINGS)
  EXPECT_CALL(http2_visitor_, OnFrameHeader(0, 0, SETTINGS, 0));
  EXPECT_CALL(http2_visitor_, OnSettingsStart());
  EXPECT_CALL(http2_visitor_, OnSettingsEnd());
  // PING
  EXPECT_CALL(http2_visitor_, OnFrameHeader(0, _, PING, 0));
  EXPECT_CALL(http2_visitor_, OnPing(42, false));

  const int64_t read_result = adapter_->ProcessBytes(frames);
  EXPECT_EQ(static_cast<size_t>(read_result), frames.size());

  EXPECT_TRUE(adapter_->want_write());

  // Server preface (SETTINGS)
  EXPECT_CALL(http2_visitor_, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(http2_visitor_, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  // SETTINGS ack
  EXPECT_CALL(http2_visitor_, OnBeforeFrameSent(SETTINGS, 0, 0, 0x1));
  EXPECT_CALL(http2_visitor_, OnFrameSent(SETTINGS, 0, 0, 0x1, 0))
      .WillOnce(testing::Return(-902));
  EXPECT_CALL(http2_visitor_, OnConnectionError(ConnectionError::kSendError));

  int send_result = adapter_->Send();
  EXPECT_LT(send_result, 0);

  EXPECT_FALSE(adapter_->want_write());

  send_result = adapter_->Send();
  EXPECT_LT(send_result, 0);
}

TEST_F(OgHttp2AdapterTest, ConnectionErrorOnDataFrameSent) {
  const std::string frames = TestFrameSequence()
                                 .ClientPreface()
                                 .Headers(1,
                                          {{":method", "GET"},
                                           {":scheme", "https"},
                                           {":authority", "example.com"},
                                           {":path", "/this/is/request/one"}},
                                          /*fin=*/true)
                                 .Serialize();
  testing::InSequence s;

  // Client preface (empty SETTINGS)
  EXPECT_CALL(http2_visitor_, OnFrameHeader(0, 0, SETTINGS, 0));
  EXPECT_CALL(http2_visitor_, OnSettingsStart());
  EXPECT_CALL(http2_visitor_, OnSettingsEnd());
  // Stream 1
  EXPECT_CALL(http2_visitor_, OnFrameHeader(1, _, HEADERS, 0x5));
  EXPECT_CALL(http2_visitor_, OnBeginHeadersForStream(1));
  EXPECT_CALL(http2_visitor_, OnHeaderForStream(1, _, _)).Times(4);
  EXPECT_CALL(http2_visitor_, OnEndHeadersForStream(1));
  EXPECT_CALL(http2_visitor_, OnEndStream(1));

  const int64_t read_result = adapter_->ProcessBytes(frames);
  EXPECT_EQ(static_cast<size_t>(read_result), frames.size());

  auto body = absl::make_unique<TestDataFrameSource>(http2_visitor_, true);
  body->AppendPayload("Here is some data, which will lead to a fatal error");
  TestDataFrameSource* body_ptr = body.get();
  int submit_result = adapter_->SubmitResponse(
      1, ToHeaders({{":status", "200"}}), std::move(body));
  ASSERT_EQ(0, submit_result);

  EXPECT_TRUE(adapter_->want_write());

  // Server preface (SETTINGS)
  EXPECT_CALL(http2_visitor_, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(http2_visitor_, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  // SETTINGS ack
  EXPECT_CALL(http2_visitor_, OnBeforeFrameSent(SETTINGS, 0, 0, 0x1));
  EXPECT_CALL(http2_visitor_, OnFrameSent(SETTINGS, 0, 0, 0x1, 0));
  // Stream 1, with doomed DATA
  EXPECT_CALL(http2_visitor_, OnBeforeFrameSent(HEADERS, 1, _, 0x4));
  EXPECT_CALL(http2_visitor_, OnFrameSent(HEADERS, 1, _, 0x4, 0));
  EXPECT_CALL(http2_visitor_, OnFrameSent(DATA, 1, _, 0x0, 0))
      .WillOnce(testing::Return(-902));
  EXPECT_CALL(http2_visitor_, OnConnectionError(ConnectionError::kSendError));

  int send_result = adapter_->Send();
  EXPECT_LT(send_result, 0);

  body_ptr->AppendPayload("After the fatal error, data will be sent no more");

  EXPECT_FALSE(adapter_->want_write());

  send_result = adapter_->Send();
  EXPECT_LT(send_result, 0);
}

TEST(OgHttp2AdapterServerTest, ClientSendsContinuation) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kServer};
  auto adapter = OgHttp2Adapter::Create(visitor, options);
  EXPECT_FALSE(adapter->want_write());

  const std::string frames = TestFrameSequence()
                                 .ClientPreface()
                                 .Headers(1,
                                          {{":method", "GET"},
                                           {":scheme", "https"},
                                           {":authority", "example.com"},
                                           {":path", "/this/is/request/one"}},
                                          /*fin=*/true,
                                          /*add_continuation=*/true)
                                 .Serialize();
  testing::InSequence s;

  // Client preface (empty SETTINGS)
  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor, OnSettingsEnd());
  // Stream 1
  EXPECT_CALL(visitor, OnFrameHeader(1, _, HEADERS, 1));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(1));
  EXPECT_CALL(visitor, OnHeaderForStream(1, ":method", "GET"));
  EXPECT_CALL(visitor, OnHeaderForStream(1, ":scheme", "https"));
  EXPECT_CALL(visitor, OnFrameHeader(1, _, CONTINUATION, 4));
  EXPECT_CALL(visitor, OnHeaderForStream(1, ":authority", "example.com"));
  EXPECT_CALL(visitor, OnHeaderForStream(1, ":path", "/this/is/request/one"));
  EXPECT_CALL(visitor, OnEndHeadersForStream(1));
  EXPECT_CALL(visitor, OnEndStream(1));

  const int64_t result = adapter->ProcessBytes(frames);
  EXPECT_EQ(frames.size(), static_cast<size_t>(result));
}

TEST(OgHttp2AdapterServerTest, ClientSendsMetadataWithContinuation) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kServer};
  auto adapter = OgHttp2Adapter::Create(visitor, options);
  EXPECT_FALSE(adapter->want_write());

  const std::string frames =
      TestFrameSequence()
          .ClientPreface()
          .Metadata(0, "Example connection metadata in multiple frames", true)
          .Headers(1,
                   {{":method", "GET"},
                    {":scheme", "https"},
                    {":authority", "example.com"},
                    {":path", "/this/is/request/one"}},
                   /*fin=*/false,
                   /*add_continuation=*/true)
          .Metadata(1,
                    "Some stream metadata that's also sent in multiple frames",
                    true)
          .Serialize();
  testing::InSequence s;

  // Client preface (empty SETTINGS)
  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor, OnSettingsEnd());
  // Metadata on stream 0
  EXPECT_CALL(visitor, OnFrameHeader(0, _, kMetadataFrameType, 0));
  EXPECT_CALL(visitor, OnBeginMetadataForStream(0, _));
  EXPECT_CALL(visitor, OnMetadataForStream(0, _));
  EXPECT_CALL(visitor, OnFrameHeader(0, _, kMetadataFrameType, 4));
  EXPECT_CALL(visitor, OnBeginMetadataForStream(0, _));
  EXPECT_CALL(visitor, OnMetadataForStream(0, _));
  EXPECT_CALL(visitor, OnMetadataEndForStream(0));

  // Stream 1
  EXPECT_CALL(visitor, OnFrameHeader(1, _, HEADERS, 0));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(1));
  EXPECT_CALL(visitor, OnHeaderForStream(1, ":method", "GET"));
  EXPECT_CALL(visitor, OnHeaderForStream(1, ":scheme", "https"));
  EXPECT_CALL(visitor, OnFrameHeader(1, _, CONTINUATION, 4));
  EXPECT_CALL(visitor, OnHeaderForStream(1, ":authority", "example.com"));
  EXPECT_CALL(visitor, OnHeaderForStream(1, ":path", "/this/is/request/one"));
  EXPECT_CALL(visitor, OnEndHeadersForStream(1));
  // Metadata on stream 1
  EXPECT_CALL(visitor, OnFrameHeader(1, _, kMetadataFrameType, 0));
  EXPECT_CALL(visitor, OnBeginMetadataForStream(1, _));
  EXPECT_CALL(visitor, OnMetadataForStream(1, _));
  EXPECT_CALL(visitor, OnFrameHeader(1, _, kMetadataFrameType, 4));
  EXPECT_CALL(visitor, OnBeginMetadataForStream(1, _));
  EXPECT_CALL(visitor, OnMetadataForStream(1, _));
  EXPECT_CALL(visitor, OnMetadataEndForStream(1));

  const int64_t result = adapter->ProcessBytes(frames);
  EXPECT_EQ(frames.size(), static_cast<size_t>(result));
  EXPECT_EQ("Example connection metadata in multiple frames",
            absl::StrJoin(visitor.GetMetadata(0), ""));
  EXPECT_EQ("Some stream metadata that's also sent in multiple frames",
            absl::StrJoin(visitor.GetMetadata(1), ""));
}

TEST(OgHttp2AdapterServerTest, RepeatedHeaderNames) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kServer};
  auto adapter = OgHttp2Adapter::Create(visitor, options);
  EXPECT_FALSE(adapter->want_write());

  const std::string frames = TestFrameSequence()
                                 .ClientPreface()
                                 .Headers(1,
                                          {{":method", "GET"},
                                           {":scheme", "https"},
                                           {":authority", "example.com"},
                                           {":path", "/this/is/request/one"},
                                           {"accept", "text/plain"},
                                           {"accept", "text/html"}},
                                          /*fin=*/true)
                                 .Serialize();

  testing::InSequence s;

  // Client preface (empty SETTINGS)
  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor, OnSettingsEnd());
  // Stream 1
  EXPECT_CALL(visitor, OnFrameHeader(1, _, HEADERS, 5));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(1));
  EXPECT_CALL(visitor, OnHeaderForStream(1, ":method", "GET"));
  EXPECT_CALL(visitor, OnHeaderForStream(1, ":scheme", "https"));
  EXPECT_CALL(visitor, OnHeaderForStream(1, ":authority", "example.com"));
  EXPECT_CALL(visitor, OnHeaderForStream(1, ":path", "/this/is/request/one"));
  EXPECT_CALL(visitor, OnHeaderForStream(1, "accept", "text/plain"));
  EXPECT_CALL(visitor, OnHeaderForStream(1, "accept", "text/html"));
  EXPECT_CALL(visitor, OnEndHeadersForStream(1));
  EXPECT_CALL(visitor, OnEndStream(1));

  int64_t result = adapter->ProcessBytes(frames);
  EXPECT_EQ(frames.size(), static_cast<size_t>(result));

  const std::vector<Header> headers1 = ToHeaders(
      {{":status", "200"}, {"content-length", "10"}, {"content-length", "10"}});
  auto body1 = absl::make_unique<TestDataFrameSource>(visitor, true);
  body1->AppendPayload("perfection");
  body1->EndData();

  int submit_result = adapter->SubmitResponse(1, headers1, std::move(body1));
  ASSERT_EQ(0, submit_result);

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x1));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x1, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(HEADERS, 1, _, 0x4));
  EXPECT_CALL(visitor, OnFrameSent(HEADERS, 1, _, 0x4, 0));
  EXPECT_CALL(visitor, OnFrameSent(DATA, 1, 10, 0x1, 0));
  EXPECT_CALL(visitor, OnCloseStream(1, Http2ErrorCode::HTTP2_NO_ERROR));

  int send_result = adapter->Send();
  EXPECT_EQ(0, send_result);
  EXPECT_THAT(visitor.data(),
              EqualsFrames({SpdyFrameType::SETTINGS, SpdyFrameType::SETTINGS,
                            SpdyFrameType::HEADERS, SpdyFrameType::DATA}));
}

TEST(OgHttp2AdapterServerTest, ServerRespondsToRequestWithTrailers) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kServer};
  auto adapter = OgHttp2Adapter::Create(visitor, options);
  EXPECT_FALSE(adapter->want_write());

  const std::string frames =
      TestFrameSequence()
          .ClientPreface()
          .Headers(1, {{":method", "GET"},
                       {":scheme", "https"},
                       {":authority", "example.com"},
                       {":path", "/this/is/request/one"}})
          .Data(1, "Example data, woohoo.")
          .Serialize();

  testing::InSequence s;

  // Client preface (empty SETTINGS)
  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor, OnSettingsEnd());
  // Stream 1
  EXPECT_CALL(visitor, OnFrameHeader(1, _, HEADERS, 4));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(1));
  EXPECT_CALL(visitor, OnHeaderForStream(1, ":method", "GET"));
  EXPECT_CALL(visitor, OnHeaderForStream(1, ":scheme", "https"));
  EXPECT_CALL(visitor, OnHeaderForStream(1, ":authority", "example.com"));
  EXPECT_CALL(visitor, OnHeaderForStream(1, ":path", "/this/is/request/one"));
  EXPECT_CALL(visitor, OnEndHeadersForStream(1));
  EXPECT_CALL(visitor, OnFrameHeader(1, _, DATA, 0));
  EXPECT_CALL(visitor, OnBeginDataForStream(1, _));
  EXPECT_CALL(visitor, OnDataForStream(1, _));

  int64_t result = adapter->ProcessBytes(frames);
  EXPECT_EQ(frames.size(), static_cast<size_t>(result));

  const std::vector<Header> headers1 = ToHeaders({{":status", "200"}});
  auto body1 = absl::make_unique<TestDataFrameSource>(visitor, true);
  TestDataFrameSource* body1_ptr = body1.get();

  int submit_result = adapter->SubmitResponse(1, headers1, std::move(body1));
  ASSERT_EQ(0, submit_result);

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x1));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x1, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(HEADERS, 1, _, 0x4));
  EXPECT_CALL(visitor, OnFrameSent(HEADERS, 1, _, 0x4, 0));

  int send_result = adapter->Send();
  EXPECT_EQ(0, send_result);
  EXPECT_THAT(visitor.data(),
              EqualsFrames({SpdyFrameType::SETTINGS, SpdyFrameType::SETTINGS,
                            SpdyFrameType::HEADERS}));
  visitor.Clear();

  const std::string more_frames =
      TestFrameSequence()
          .Headers(1, {{"extra-info", "Trailers are weird but good?"}},
                   /*fin=*/true)
          .Serialize();

  EXPECT_CALL(visitor, OnFrameHeader(1, _, HEADERS, 5));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(1));
  EXPECT_CALL(visitor, OnHeaderForStream(1, "extra-info",
                                         "Trailers are weird but good?"));
  EXPECT_CALL(visitor, OnEndHeadersForStream(1));
  EXPECT_CALL(visitor, OnEndStream(1));

  result = adapter->ProcessBytes(more_frames);
  EXPECT_EQ(more_frames.size(), static_cast<size_t>(result));

  body1_ptr->EndData();
  EXPECT_EQ(true, adapter->ResumeStream(1));

  EXPECT_CALL(visitor, OnFrameSent(DATA, 1, 0, 0x1, 0));
  EXPECT_CALL(visitor, OnCloseStream(1, Http2ErrorCode::HTTP2_NO_ERROR));

  send_result = adapter->Send();
  EXPECT_EQ(0, send_result);
  EXPECT_THAT(visitor.data(), EqualsFrames({SpdyFrameType::DATA}));
}

TEST(OgHttp2AdapterServerTest, ServerReceivesMoreHeaderBytesThanConfigured) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kServer,
                                  .max_header_list_bytes = 42};
  auto adapter = OgHttp2Adapter::Create(visitor, options);
  EXPECT_FALSE(adapter->want_write());

  const std::string frames =
      TestFrameSequence()
          .ClientPreface()
          .Headers(1,
                   {{":method", "GET"},
                    {":scheme", "https"},
                    {":authority", "example.com"},
                    {":path", "/this/is/request/one"},
                    {"from-douglas-de-fermat",
                     "I have discovered a truly marvelous answer to the life, "
                     "the universe, and everything that the header setting is "
                     "too narrow to contain."}},
                   /*fin=*/true)
          .Serialize();

  testing::InSequence s;

  // Client preface (empty SETTINGS)
  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor, OnSettingsEnd());
  // Stream 1
  EXPECT_CALL(visitor, OnFrameHeader(1, _, HEADERS, 0x5));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(1));
  EXPECT_CALL(visitor, OnConnectionError(ConnectionError::kParseError));

  int64_t result = adapter->ProcessBytes(frames);
  EXPECT_EQ(static_cast<size_t>(result), frames.size());

  EXPECT_TRUE(adapter->want_write());

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(GOAWAY, 0, _, 0x0));
  EXPECT_CALL(visitor,
              OnFrameSent(GOAWAY, 0, _, 0x0,
                          static_cast<int>(Http2ErrorCode::COMPRESSION_ERROR)));

  int send_result = adapter->Send();
  // Some bytes should have been serialized.
  EXPECT_EQ(0, send_result);
  EXPECT_THAT(visitor.data(),
              EqualsFrames({SpdyFrameType::SETTINGS, SpdyFrameType::GOAWAY}));
}

TEST(OgHttp2AdapterServerTest, ServerSubmitsResponseWithDataSourceError) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kServer};
  auto adapter = OgHttp2Adapter::Create(visitor, options);
  EXPECT_FALSE(adapter->want_write());

  const std::string frames = TestFrameSequence()
                                 .ClientPreface()
                                 .Headers(1,
                                          {{":method", "GET"},
                                           {":scheme", "https"},
                                           {":authority", "example.com"},
                                           {":path", "/this/is/request/one"}},
                                          /*fin=*/true)
                                 .Serialize();
  testing::InSequence s;

  // Client preface (empty SETTINGS)
  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor, OnSettingsEnd());
  // Stream 1
  EXPECT_CALL(visitor, OnFrameHeader(1, _, HEADERS, 5));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(1));
  EXPECT_CALL(visitor, OnHeaderForStream(1, ":method", "GET"));
  EXPECT_CALL(visitor, OnHeaderForStream(1, ":scheme", "https"));
  EXPECT_CALL(visitor, OnHeaderForStream(1, ":authority", "example.com"));
  EXPECT_CALL(visitor, OnHeaderForStream(1, ":path", "/this/is/request/one"));
  EXPECT_CALL(visitor, OnEndHeadersForStream(1));
  EXPECT_CALL(visitor, OnEndStream(1));

  const int64_t result = adapter->ProcessBytes(frames);
  EXPECT_EQ(frames.size(), static_cast<size_t>(result));

  auto body1 = absl::make_unique<TestDataFrameSource>(visitor, false);
  body1->SimulateError();
  int submit_result = adapter->SubmitResponse(
      1, ToHeaders({{":status", "200"}, {"x-comment", "Sure, sounds good."}}),
      std::move(body1));
  EXPECT_EQ(submit_result, 0);
  EXPECT_TRUE(adapter->want_write());

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x1));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x1, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(HEADERS, 1, _, 0x4));
  EXPECT_CALL(visitor, OnFrameSent(HEADERS, 1, _, 0x4, 0));
  // TODO(birenroy): Send RST_STREAM INTERNAL_ERROR to the client as well.
  EXPECT_CALL(visitor, OnCloseStream(1, Http2ErrorCode::INTERNAL_ERROR));

  int send_result = adapter->Send();
  EXPECT_EQ(0, send_result);
  EXPECT_THAT(visitor.data(),
              EqualsFrames({SpdyFrameType::SETTINGS, SpdyFrameType::SETTINGS,
                            SpdyFrameType::HEADERS}));
  visitor.Clear();
  EXPECT_FALSE(adapter->want_write());

  // Since the stream has been closed, it is not possible to submit trailers for
  // the stream.
  int trailer_result =
      adapter->SubmitTrailer(1, ToHeaders({{":final-status", "a-ok"}}));
  ASSERT_LT(trailer_result, 0);
  EXPECT_FALSE(adapter->want_write());
}

TEST(OgHttp2AdapterServerTest, CompleteRequestWithServerResponse) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kServer};
  auto adapter = OgHttp2Adapter::Create(visitor, options);
  EXPECT_FALSE(adapter->want_write());

  const std::string frames =
      TestFrameSequence()
          .ClientPreface()
          .Headers(1,
                   {{":method", "GET"},
                    {":scheme", "https"},
                    {":authority", "example.com"},
                    {":path", "/this/is/request/one"}},
                   /*fin=*/false)
          .Data(1, "This is the response body.", /*fin=*/true)
          .Serialize();
  testing::InSequence s;

  // Client preface (empty SETTINGS)
  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor, OnSettingsEnd());
  // Stream 1
  EXPECT_CALL(visitor, OnFrameHeader(1, _, HEADERS, 4));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(1));
  EXPECT_CALL(visitor, OnHeaderForStream(1, _, _)).Times(4);
  EXPECT_CALL(visitor, OnEndHeadersForStream(1));
  EXPECT_CALL(visitor, OnFrameHeader(1, _, DATA, 1));
  EXPECT_CALL(visitor, OnBeginDataForStream(1, _));
  EXPECT_CALL(visitor, OnDataForStream(1, _));
  EXPECT_CALL(visitor, OnEndStream(1));

  const int64_t result = adapter->ProcessBytes(frames);
  EXPECT_EQ(frames.size(), static_cast<size_t>(result));

  int submit_result =
      adapter->SubmitResponse(1, ToHeaders({{":status", "200"}}), nullptr);
  EXPECT_EQ(submit_result, 0);
  EXPECT_TRUE(adapter->want_write());

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x1));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x1, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(HEADERS, 1, _, 0x5));
  EXPECT_CALL(visitor, OnFrameSent(HEADERS, 1, _, 0x5, 0));
  EXPECT_CALL(visitor, OnCloseStream(1, Http2ErrorCode::HTTP2_NO_ERROR));

  int send_result = adapter->Send();
  EXPECT_EQ(0, send_result);
  EXPECT_THAT(visitor.data(),
              EqualsFrames({SpdyFrameType::SETTINGS, SpdyFrameType::SETTINGS,
                            SpdyFrameType::HEADERS}));
  EXPECT_FALSE(adapter->want_write());
}

TEST(OgHttp2AdapterServerTest, IncompleteRequestWithServerResponse) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kServer};
  auto adapter = OgHttp2Adapter::Create(visitor, options);
  EXPECT_FALSE(adapter->want_write());

  const std::string frames = TestFrameSequence()
                                 .ClientPreface()
                                 .Headers(1,
                                          {{":method", "GET"},
                                           {":scheme", "https"},
                                           {":authority", "example.com"},
                                           {":path", "/this/is/request/one"}},
                                          /*fin=*/false)
                                 .Serialize();
  testing::InSequence s;

  // Client preface (empty SETTINGS)
  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor, OnSettingsEnd());
  // Stream 1
  EXPECT_CALL(visitor, OnFrameHeader(1, _, HEADERS, 4));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(1));
  EXPECT_CALL(visitor, OnHeaderForStream(1, _, _)).Times(4);
  EXPECT_CALL(visitor, OnEndHeadersForStream(1));

  const int64_t result = adapter->ProcessBytes(frames);
  EXPECT_EQ(frames.size(), static_cast<size_t>(result));

  int submit_result =
      adapter->SubmitResponse(1, ToHeaders({{":status", "200"}}), nullptr);
  EXPECT_EQ(submit_result, 0);
  EXPECT_TRUE(adapter->want_write());

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x1));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x1, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(HEADERS, 1, _, 0x5));
  EXPECT_CALL(visitor, OnFrameSent(HEADERS, 1, _, 0x5, 0));
  // RST_STREAM NO_ERROR option is disabled.

  int send_result = adapter->Send();
  EXPECT_EQ(0, send_result);
  EXPECT_THAT(visitor.data(),
              EqualsFrames({SpdyFrameType::SETTINGS, SpdyFrameType::SETTINGS,
                            SpdyFrameType::HEADERS}));
  EXPECT_FALSE(adapter->want_write());
}

TEST(OgHttp2AdapterServerTest,
     IncompleteRequestWithServerResponseRstStreamEnabled) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kServer,
                                  .rst_stream_no_error_when_incomplete = true};
  auto adapter = OgHttp2Adapter::Create(visitor, options);
  EXPECT_FALSE(adapter->want_write());

  const std::string frames = TestFrameSequence()
                                 .ClientPreface()
                                 .Headers(1,
                                          {{":method", "GET"},
                                           {":scheme", "https"},
                                           {":authority", "example.com"},
                                           {":path", "/this/is/request/one"}},
                                          /*fin=*/false)
                                 .Serialize();
  testing::InSequence s;

  // Client preface (empty SETTINGS)
  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor, OnSettingsEnd());
  // Stream 1
  EXPECT_CALL(visitor, OnFrameHeader(1, _, HEADERS, 4));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(1));
  EXPECT_CALL(visitor, OnHeaderForStream(1, _, _)).Times(4);
  EXPECT_CALL(visitor, OnEndHeadersForStream(1));

  const int64_t result = adapter->ProcessBytes(frames);
  EXPECT_EQ(frames.size(), static_cast<size_t>(result));

  int submit_result =
      adapter->SubmitResponse(1, ToHeaders({{":status", "200"}}), nullptr);
  EXPECT_EQ(submit_result, 0);
  EXPECT_TRUE(adapter->want_write());

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x1));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x1, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(HEADERS, 1, _, 0x5));
  EXPECT_CALL(visitor, OnFrameSent(HEADERS, 1, _, 0x5, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(RST_STREAM, 1, 4, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(RST_STREAM, 1, 4, 0x0, 0));
  EXPECT_CALL(visitor, OnCloseStream(1, Http2ErrorCode::HTTP2_NO_ERROR));

  int send_result = adapter->Send();
  EXPECT_EQ(0, send_result);
  EXPECT_THAT(
      visitor.data(),
      EqualsFrames({SpdyFrameType::SETTINGS, SpdyFrameType::SETTINGS,
                    SpdyFrameType::HEADERS, SpdyFrameType::RST_STREAM}));
  EXPECT_FALSE(adapter->want_write());
}

TEST(OgHttp2AdapterServerTest, ServerSendsInvalidTrailers) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kServer};
  auto adapter = OgHttp2Adapter::Create(visitor, options);
  EXPECT_FALSE(adapter->want_write());

  const std::string frames = TestFrameSequence()
                                 .ClientPreface()
                                 .Headers(1,
                                          {{":method", "GET"},
                                           {":scheme", "https"},
                                           {":authority", "example.com"},
                                           {":path", "/this/is/request/one"}},
                                          /*fin=*/true)
                                 .Serialize();
  testing::InSequence s;

  // Client preface (empty SETTINGS)
  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor, OnSettingsEnd());
  // Stream 1
  EXPECT_CALL(visitor, OnFrameHeader(1, _, HEADERS, 5));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(1));
  EXPECT_CALL(visitor, OnHeaderForStream(1, ":method", "GET"));
  EXPECT_CALL(visitor, OnHeaderForStream(1, ":scheme", "https"));
  EXPECT_CALL(visitor, OnHeaderForStream(1, ":authority", "example.com"));
  EXPECT_CALL(visitor, OnHeaderForStream(1, ":path", "/this/is/request/one"));
  EXPECT_CALL(visitor, OnEndHeadersForStream(1));
  EXPECT_CALL(visitor, OnEndStream(1));

  const int64_t result = adapter->ProcessBytes(frames);
  EXPECT_EQ(frames.size(), static_cast<size_t>(result));

  const absl::string_view kBody = "This is an example response body.";

  // The body source must indicate that the end of the body is not the end of
  // the stream.
  auto body1 = absl::make_unique<TestDataFrameSource>(visitor, false);
  body1->AppendPayload(kBody);
  body1->EndData();
  int submit_result = adapter->SubmitResponse(
      1, ToHeaders({{":status", "200"}, {"x-comment", "Sure, sounds good."}}),
      std::move(body1));
  EXPECT_EQ(submit_result, 0);
  EXPECT_TRUE(adapter->want_write());

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x1));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x1, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(HEADERS, 1, _, 0x4));
  EXPECT_CALL(visitor, OnFrameSent(HEADERS, 1, _, 0x4, 0));
  EXPECT_CALL(visitor, OnFrameSent(DATA, 1, _, 0x0, 0));

  int send_result = adapter->Send();
  EXPECT_EQ(0, send_result);
  EXPECT_THAT(visitor.data(),
              EqualsFrames({SpdyFrameType::SETTINGS, SpdyFrameType::SETTINGS,
                            SpdyFrameType::HEADERS, SpdyFrameType::DATA}));
  EXPECT_THAT(visitor.data(), testing::HasSubstr(kBody));
  visitor.Clear();
  EXPECT_FALSE(adapter->want_write());

  // The body source has been exhausted by the call to Send() above.
  int trailer_result =
      adapter->SubmitTrailer(1, ToHeaders({{":final-status", "a-ok"}}));
  ASSERT_EQ(trailer_result, 0);
  EXPECT_TRUE(adapter->want_write());

  EXPECT_CALL(visitor, OnBeforeFrameSent(HEADERS, 1, _, 0x5));
  EXPECT_CALL(visitor, OnFrameSent(HEADERS, 1, _, 0x5, 0));
  EXPECT_CALL(visitor, OnCloseStream(1, Http2ErrorCode::HTTP2_NO_ERROR));

  send_result = adapter->Send();
  EXPECT_EQ(0, send_result);
  EXPECT_THAT(visitor.data(), EqualsFrames({SpdyFrameType::HEADERS}));
}

TEST(OgHttp2AdapterServerTest, ServerHandlesDataWithPadding) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kServer};
  auto adapter = OgHttp2Adapter::Create(visitor, options);

  const std::string frames = TestFrameSequence()
                                 .ClientPreface()
                                 .Headers(1,
                                          {{":method", "POST"},
                                           {":scheme", "https"},
                                           {":authority", "example.com"},
                                           {":path", "/this/is/request/one"}},
                                          /*fin=*/false)
                                 .Data(1, "This is the request body.",
                                       /*fin=*/true, /*padding_length=*/39)
                                 .Headers(3,
                                          {{":method", "GET"},
                                           {":scheme", "http"},
                                           {":authority", "example.com"},
                                           {":path", "/this/is/request/two"}},
                                          /*fin=*/true)
                                 .Serialize();
  testing::InSequence s;

  // Client preface (empty SETTINGS)
  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor, OnSettingsEnd());

  EXPECT_CALL(visitor, OnFrameHeader(1, _, HEADERS, 4));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(1));
  EXPECT_CALL(visitor, OnHeaderForStream(1, _, _)).Times(4);
  EXPECT_CALL(visitor, OnEndHeadersForStream(1));
  EXPECT_CALL(visitor, OnFrameHeader(1, 25 + 39, DATA, 0x9));
  EXPECT_CALL(visitor, OnBeginDataForStream(1, 25 + 39));
  // Note: oghttp2 passes padding information before the actual data.
  EXPECT_CALL(visitor, OnDataPaddingLength(1, 39));
  EXPECT_CALL(visitor, OnDataForStream(1, "This is the request body."));
  EXPECT_CALL(visitor, OnEndStream(1));
  EXPECT_CALL(visitor, OnFrameHeader(3, _, HEADERS, 5));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(3));
  EXPECT_CALL(visitor, OnHeaderForStream(3, _, _)).Times(4);
  EXPECT_CALL(visitor, OnEndHeadersForStream(3));
  EXPECT_CALL(visitor, OnEndStream(3));

  const int64_t result = adapter->ProcessBytes(frames);
  EXPECT_EQ(static_cast<int64_t>(frames.size()), result);

  EXPECT_TRUE(adapter->want_write());

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, 0, 0x1));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, 0, 0x1, 0));

  int send_result = adapter->Send();
  EXPECT_EQ(0, send_result);
  EXPECT_THAT(visitor.data(),
              EqualsFrames({SpdyFrameType::SETTINGS, SpdyFrameType::SETTINGS}));
}

// Tests the case where the response body is in the progress of being sent while
// trailers are queued.
TEST(OgHttp2AdapterServerTest, ServerSubmitsTrailersWhileDataDeferred) {
  DataSavingVisitor visitor;
  for (const bool queue_trailers : {true, false}) {
    OgHttp2Adapter::Options options{
        .perspective = Perspective::kServer,
        .trailers_require_end_data = queue_trailers};
    auto adapter = OgHttp2Adapter::Create(visitor, options);

    const std::string frames = TestFrameSequence()
                                   .ClientPreface()
                                   .Headers(1,
                                            {{":method", "POST"},
                                             {":scheme", "https"},
                                             {":authority", "example.com"},
                                             {":path", "/this/is/request/one"}},
                                            /*fin=*/false)
                                   .WindowUpdate(1, 2000)
                                   .Data(1, "This is the request body.")
                                   .WindowUpdate(0, 2000)
                                   .Serialize();
    testing::InSequence s;

    // Client preface (empty SETTINGS)
    EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0));
    EXPECT_CALL(visitor, OnSettingsStart());
    EXPECT_CALL(visitor, OnSettingsEnd());

    EXPECT_CALL(visitor, OnFrameHeader(1, _, HEADERS, 4));
    EXPECT_CALL(visitor, OnBeginHeadersForStream(1));
    EXPECT_CALL(visitor, OnHeaderForStream(1, _, _)).Times(4);
    EXPECT_CALL(visitor, OnEndHeadersForStream(1));
    EXPECT_CALL(visitor, OnFrameHeader(1, 4, WINDOW_UPDATE, 0));
    EXPECT_CALL(visitor, OnWindowUpdate(1, 2000));
    EXPECT_CALL(visitor, OnFrameHeader(1, _, DATA, 0));
    EXPECT_CALL(visitor, OnBeginDataForStream(1, _));
    EXPECT_CALL(visitor, OnDataForStream(1, "This is the request body."));
    EXPECT_CALL(visitor, OnFrameHeader(0, 4, WINDOW_UPDATE, 0));
    EXPECT_CALL(visitor, OnWindowUpdate(0, 2000));

    const int64_t result = adapter->ProcessBytes(frames);
    EXPECT_EQ(frames.size(), static_cast<size_t>(result));

    EXPECT_TRUE(adapter->want_write());

    EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
    EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
    EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, 0, 0x1));
    EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, 0, 0x1, 0));

    int send_result = adapter->Send();
    EXPECT_EQ(0, send_result);
    visitor.Clear();

    const absl::string_view kBody = "This is an example response body.";

    // The body source must indicate that the end of the body is not the end of
    // the stream.
    auto body1 = absl::make_unique<TestDataFrameSource>(visitor, false);
    body1->AppendPayload(kBody);
    auto* body1_ptr = body1.get();
    int submit_result = adapter->SubmitResponse(
        1, ToHeaders({{":status", "200"}, {"x-comment", "Sure, sounds good."}}),
        std::move(body1));
    EXPECT_EQ(submit_result, 0);
    EXPECT_TRUE(adapter->want_write());

    EXPECT_CALL(visitor, OnBeforeFrameSent(HEADERS, 1, _, 0x4));
    EXPECT_CALL(visitor, OnFrameSent(HEADERS, 1, _, 0x4, 0));
    EXPECT_CALL(visitor, OnFrameSent(DATA, 1, _, 0x0, 0));

    send_result = adapter->Send();
    EXPECT_EQ(0, send_result);
    visitor.Clear();
    EXPECT_FALSE(adapter->want_write());

    int trailer_result =
        adapter->SubmitTrailer(1, ToHeaders({{"final-status", "a-ok"}}));
    ASSERT_EQ(trailer_result, 0);
    if (queue_trailers) {
      // Even though there are new trailers to write, the data source has not
      // finished writing data and is blocked.
      EXPECT_FALSE(adapter->want_write());

      body1_ptr->EndData();
      adapter->ResumeStream(1);
      EXPECT_TRUE(adapter->want_write());

      EXPECT_CALL(visitor, OnBeforeFrameSent(HEADERS, 1, _, 0x5));
      EXPECT_CALL(visitor, OnFrameSent(HEADERS, 1, _, 0x5, 0));

      send_result = adapter->Send();
      EXPECT_EQ(0, send_result);
    } else {
      // Even though the data source has not finished sending data, the library
      // will write the trailers anyway.
      EXPECT_TRUE(adapter->want_write());

      EXPECT_CALL(visitor, OnBeforeFrameSent(HEADERS, 1, _, 0x5));
      EXPECT_CALL(visitor, OnFrameSent(HEADERS, 1, _, 0x5, 0));

      send_result = adapter->Send();
      EXPECT_EQ(0, send_result);
      EXPECT_THAT(visitor.data(), EqualsFrames({SpdyFrameType::HEADERS}));
    }
  }
}

TEST(OgHttp2AdapterServerTest, ServerErrorWhileHandlingHeaders) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kServer};
  auto adapter = OgHttp2Adapter::Create(visitor, options);

  const std::string frames = TestFrameSequence()
                                 .ClientPreface()
                                 .Headers(1,
                                          {{":method", "POST"},
                                           {":scheme", "https"},
                                           {":authority", "example.com"},
                                           {":path", "/this/is/request/one"},
                                           {"accept", "some bogus value!"}},
                                          /*fin=*/false)
                                 .WindowUpdate(1, 2000)
                                 .Data(1, "This is the request body.")
                                 .WindowUpdate(0, 2000)
                                 .Serialize();
  testing::InSequence s;

  // Client preface (empty SETTINGS)
  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor, OnSettingsEnd());

  EXPECT_CALL(visitor, OnFrameHeader(1, _, HEADERS, 4));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(1));
  EXPECT_CALL(visitor, OnHeaderForStream(1, ":method", "POST"));
  EXPECT_CALL(visitor, OnHeaderForStream(1, ":scheme", "https"));
  EXPECT_CALL(visitor, OnHeaderForStream(1, ":authority", "example.com"));
  EXPECT_CALL(visitor, OnHeaderForStream(1, ":path", "/this/is/request/one"));
  EXPECT_CALL(visitor, OnHeaderForStream(1, "accept", "some bogus value!"))
      .WillOnce(testing::Return(Http2VisitorInterface::HEADER_RST_STREAM));
  // Stream WINDOW_UPDATE and DATA frames are not delivered to the visitor.
  EXPECT_CALL(visitor, OnFrameHeader(0, 4, WINDOW_UPDATE, 0));
  EXPECT_CALL(visitor, OnWindowUpdate(0, 2000));

  const int64_t result = adapter->ProcessBytes(frames);
  EXPECT_EQ(frames.size(), static_cast<size_t>(result));

  EXPECT_TRUE(adapter->want_write());

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, 0, 0x1));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, 0, 0x1, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(RST_STREAM, 1, 4, 0x0));
  EXPECT_CALL(visitor,
              OnFrameSent(RST_STREAM, 1, 4, 0x0,
                          static_cast<int>(Http2ErrorCode::INTERNAL_ERROR)));
  EXPECT_CALL(visitor, OnCloseStream(1, Http2ErrorCode::HTTP2_NO_ERROR));

  int send_result = adapter->Send();
  // Some bytes should have been serialized.
  EXPECT_EQ(0, send_result);
  // SETTINGS ack
  EXPECT_THAT(visitor.data(),
              EqualsFrames({SpdyFrameType::SETTINGS, SpdyFrameType::SETTINGS,
                            SpdyFrameType::RST_STREAM}));
}

TEST(OgHttp2AdapterServerTest, ServerErrorWhileHandlingHeadersDropsFrames) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kServer};
  auto adapter = OgHttp2Adapter::Create(visitor, options);

  const std::string frames = TestFrameSequence()
                                 .ClientPreface()
                                 .Headers(1,
                                          {{":method", "POST"},
                                           {":scheme", "https"},
                                           {":authority", "example.com"},
                                           {":path", "/this/is/request/one"},
                                           {"accept", "some bogus value!"}},
                                          /*fin=*/false)
                                 .WindowUpdate(1, 2000)
                                 .Data(1, "This is the request body.")
                                 .Metadata(1, "This is the request metadata.")
                                 .RstStream(1, Http2ErrorCode::CANCEL)
                                 .WindowUpdate(0, 2000)
                                 .Headers(3,
                                          {{":method", "GET"},
                                           {":scheme", "https"},
                                           {":authority", "example.com"},
                                           {":path", "/this/is/request/two"}},
                                          /*fin=*/false)
                                 .Metadata(3, "This is the request metadata.",
                                           /*multiple_frames=*/true)
                                 .Serialize();
  testing::InSequence s;

  // Client preface (empty SETTINGS)
  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor, OnSettingsEnd());

  EXPECT_CALL(visitor, OnFrameHeader(1, _, HEADERS, 4));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(1));
  EXPECT_CALL(visitor, OnHeaderForStream(1, _, _)).Times(4);
  EXPECT_CALL(visitor, OnHeaderForStream(1, "accept", "some bogus value!"))
      .WillOnce(testing::Return(Http2VisitorInterface::HEADER_RST_STREAM));
  // Frames for the RST_STREAM-marked stream are not delivered to the visitor.
  // Note: nghttp2 still delivers control frames and metadata for the stream.
  EXPECT_CALL(visitor, OnFrameHeader(0, 4, WINDOW_UPDATE, 0));
  EXPECT_CALL(visitor, OnWindowUpdate(0, 2000));
  EXPECT_CALL(visitor, OnFrameHeader(3, _, HEADERS, 4));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(3));
  EXPECT_CALL(visitor, OnHeaderForStream(3, _, _)).Times(4);
  EXPECT_CALL(visitor, OnEndHeadersForStream(3));
  EXPECT_CALL(visitor, OnFrameHeader(3, _, kMetadataFrameType, 0));
  EXPECT_CALL(visitor, OnBeginMetadataForStream(3, _));
  EXPECT_CALL(visitor, OnMetadataForStream(3, "This is the re"))
      .WillOnce(testing::DoAll(testing::InvokeWithoutArgs([&adapter]() {
                                 adapter->SubmitRst(
                                     3, Http2ErrorCode::REFUSED_STREAM);
                               }),
                               testing::Return(true)));
  // The rest of the metadata is not delivered to the visitor.

  const int64_t result = adapter->ProcessBytes(frames);
  EXPECT_EQ(frames.size(), static_cast<size_t>(result));

  EXPECT_TRUE(adapter->want_write());

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, 0, 0x1));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, 0, 0x1, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(RST_STREAM, 1, 4, 0x0));
  EXPECT_CALL(visitor,
              OnFrameSent(RST_STREAM, 1, 4, 0x0,
                          static_cast<int>(Http2ErrorCode::INTERNAL_ERROR)));
  EXPECT_CALL(visitor, OnCloseStream(1, Http2ErrorCode::HTTP2_NO_ERROR));
  EXPECT_CALL(visitor, OnBeforeFrameSent(RST_STREAM, 3, 4, 0x0));
  EXPECT_CALL(visitor,
              OnFrameSent(RST_STREAM, 3, 4, 0x0,
                          static_cast<int>(Http2ErrorCode::REFUSED_STREAM)));
  EXPECT_CALL(visitor, OnCloseStream(3, Http2ErrorCode::HTTP2_NO_ERROR));

  int send_result = adapter->Send();
  // Some bytes should have been serialized.
  EXPECT_EQ(0, send_result);
  // SETTINGS ack
  EXPECT_THAT(
      visitor.data(),
      EqualsFrames({SpdyFrameType::SETTINGS, SpdyFrameType::SETTINGS,
                    SpdyFrameType::RST_STREAM, SpdyFrameType::RST_STREAM}));
}

TEST(OgHttp2AdapterServerTest, ServerConnectionErrorWhileHandlingHeaders) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kServer};
  auto adapter = OgHttp2Adapter::Create(visitor, options);

  const std::string frames = TestFrameSequence()
                                 .ClientPreface()
                                 .Headers(1,
                                          {{":method", "POST"},
                                           {":scheme", "https"},
                                           {":authority", "example.com"},
                                           {":path", "/this/is/request/one"},
                                           {"Accept", "uppercase, oh boy!"}},
                                          /*fin=*/false)
                                 .WindowUpdate(1, 2000)
                                 .Data(1, "This is the request body.")
                                 .WindowUpdate(0, 2000)
                                 .Serialize();
  testing::InSequence s;

  // Client preface (empty SETTINGS)
  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor, OnSettingsEnd());

  EXPECT_CALL(visitor, OnFrameHeader(1, _, HEADERS, 4));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(1));
  EXPECT_CALL(visitor, OnHeaderForStream(1, ":method", "POST"));
  EXPECT_CALL(visitor, OnHeaderForStream(1, ":scheme", "https"));
  EXPECT_CALL(visitor, OnHeaderForStream(1, ":authority", "example.com"));
  EXPECT_CALL(visitor, OnHeaderForStream(1, ":path", "/this/is/request/one"));
  EXPECT_CALL(
      visitor,
      OnInvalidFrame(1, Http2VisitorInterface::InvalidFrameError::kHttpHeader))
      .WillOnce(testing::Return(false));
  EXPECT_CALL(visitor, OnConnectionError(ConnectionError::kHeaderError));

  const int64_t result = adapter->ProcessBytes(frames);
  EXPECT_LT(result, 0);

  EXPECT_TRUE(adapter->want_write());

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(RST_STREAM, 1, 4, 0x0));
  EXPECT_CALL(visitor,
              OnFrameSent(RST_STREAM, 1, 4, 0x0,
                          static_cast<int>(Http2ErrorCode::PROTOCOL_ERROR)));
  EXPECT_CALL(visitor, OnCloseStream(1, Http2ErrorCode::HTTP2_NO_ERROR));
  EXPECT_CALL(visitor, OnBeforeFrameSent(GOAWAY, 0, _, 0x0));
  EXPECT_CALL(visitor,
              OnFrameSent(GOAWAY, 0, _, 0x0,
                          static_cast<int>(Http2ErrorCode::PROTOCOL_ERROR)));

  int send_result = adapter->Send();
  // Some bytes should have been serialized.
  EXPECT_EQ(0, send_result);
  EXPECT_THAT(visitor.data(),
              EqualsFrames({SpdyFrameType::SETTINGS, SpdyFrameType::RST_STREAM,
                            SpdyFrameType::GOAWAY}));
}

TEST(OgHttp2AdapterServerTest, ServerErrorAfterHandlingHeaders) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kServer};
  auto adapter = OgHttp2Adapter::Create(visitor, options);

  const std::string frames = TestFrameSequence()
                                 .ClientPreface()
                                 .Headers(1,
                                          {{":method", "POST"},
                                           {":scheme", "https"},
                                           {":authority", "example.com"},
                                           {":path", "/this/is/request/one"}},
                                          /*fin=*/false)
                                 .WindowUpdate(1, 2000)
                                 .Data(1, "This is the request body.")
                                 .WindowUpdate(0, 2000)
                                 .Serialize();
  testing::InSequence s;

  // Client preface (empty SETTINGS)
  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor, OnSettingsEnd());

  EXPECT_CALL(visitor, OnFrameHeader(1, _, HEADERS, 4));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(1));
  EXPECT_CALL(visitor, OnHeaderForStream(1, ":method", "POST"));
  EXPECT_CALL(visitor, OnHeaderForStream(1, ":scheme", "https"));
  EXPECT_CALL(visitor, OnHeaderForStream(1, ":authority", "example.com"));
  EXPECT_CALL(visitor, OnHeaderForStream(1, ":path", "/this/is/request/one"));
  EXPECT_CALL(visitor, OnEndHeadersForStream(1))
      .WillOnce(testing::Return(false));
  EXPECT_CALL(visitor, OnConnectionError(ConnectionError::kParseError));

  const int64_t result = adapter->ProcessBytes(frames);
  EXPECT_LT(result, 0);

  EXPECT_TRUE(adapter->want_write());

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(GOAWAY, 0, _, 0x0));
  EXPECT_CALL(visitor,
              OnFrameSent(GOAWAY, 0, _, 0x0,
                          static_cast<int>(Http2ErrorCode::INTERNAL_ERROR)));

  int send_result = adapter->Send();
  // Some bytes should have been serialized.
  EXPECT_EQ(0, send_result);
  EXPECT_THAT(visitor.data(),
              EqualsFrames({SpdyFrameType::SETTINGS, SpdyFrameType::GOAWAY}));
}

// Exercises the case when a visitor chooses to reject a frame based solely on
// the frame header, which is a fatal error for the connection.
TEST(OgHttp2AdapterServerTest, ServerRejectsFrameHeader) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kServer};
  auto adapter = OgHttp2Adapter::Create(visitor, options);

  const std::string frames = TestFrameSequence()
                                 .ClientPreface()
                                 .Ping(64)
                                 .Headers(1,
                                          {{":method", "POST"},
                                           {":scheme", "https"},
                                           {":authority", "example.com"},
                                           {":path", "/this/is/request/one"}},
                                          /*fin=*/false)
                                 .WindowUpdate(1, 2000)
                                 .Data(1, "This is the request body.")
                                 .WindowUpdate(0, 2000)
                                 .Serialize();
  testing::InSequence s;

  // Client preface (empty SETTINGS)
  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor, OnSettingsEnd());

  EXPECT_CALL(visitor, OnFrameHeader(0, 8, PING, 0))
      .WillOnce(testing::Return(false));
  EXPECT_CALL(visitor, OnConnectionError(ConnectionError::kParseError));

  const int64_t result = adapter->ProcessBytes(frames);
  EXPECT_LT(result, 0);

  EXPECT_TRUE(adapter->want_write());

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(GOAWAY, 0, _, 0x0));
  EXPECT_CALL(visitor,
              OnFrameSent(GOAWAY, 0, _, 0x0,
                          static_cast<int>(Http2ErrorCode::INTERNAL_ERROR)));

  int send_result = adapter->Send();
  // Some bytes should have been serialized.
  EXPECT_EQ(0, send_result);
  EXPECT_THAT(visitor.data(),
              EqualsFrames({SpdyFrameType::SETTINGS, SpdyFrameType::GOAWAY}));
}

TEST(OgHttp2AdapterServerTest, ServerRejectsBeginningOfData) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kServer};
  auto adapter = OgHttp2Adapter::Create(visitor, options);

  const std::string frames = TestFrameSequence()
                                 .ClientPreface()
                                 .Headers(1,
                                          {{":method", "POST"},
                                           {":scheme", "https"},
                                           {":authority", "example.com"},
                                           {":path", "/this/is/request/one"}},
                                          /*fin=*/false)
                                 .Data(1, "This is the request body.")
                                 .Headers(3,
                                          {{":method", "GET"},
                                           {":scheme", "http"},
                                           {":authority", "example.com"},
                                           {":path", "/this/is/request/two"}},
                                          /*fin=*/true)
                                 .RstStream(3, Http2ErrorCode::CANCEL)
                                 .Ping(47)
                                 .Serialize();
  testing::InSequence s;

  // Client preface (empty SETTINGS)
  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor, OnSettingsEnd());

  EXPECT_CALL(visitor, OnFrameHeader(1, _, HEADERS, 4));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(1));
  EXPECT_CALL(visitor, OnHeaderForStream(1, ":method", "POST"));
  EXPECT_CALL(visitor, OnHeaderForStream(1, ":scheme", "https"));
  EXPECT_CALL(visitor, OnHeaderForStream(1, ":authority", "example.com"));
  EXPECT_CALL(visitor, OnHeaderForStream(1, ":path", "/this/is/request/one"));
  EXPECT_CALL(visitor, OnEndHeadersForStream(1));
  EXPECT_CALL(visitor, OnFrameHeader(1, 25, DATA, 0));
  EXPECT_CALL(visitor, OnBeginDataForStream(1, 25))
      .WillOnce(testing::Return(false));
  EXPECT_CALL(visitor, OnConnectionError(ConnectionError::kParseError));

  const int64_t result = adapter->ProcessBytes(frames);
  EXPECT_LT(result, 0);

  EXPECT_TRUE(adapter->want_write());

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(GOAWAY, 0, _, 0x0));
  EXPECT_CALL(visitor,
              OnFrameSent(GOAWAY, 0, _, 0x0,
                          static_cast<int>(Http2ErrorCode::INTERNAL_ERROR)));

  int send_result = adapter->Send();
  // Some bytes should have been serialized.
  EXPECT_EQ(0, send_result);
  EXPECT_THAT(visitor.data(),
              EqualsFrames({SpdyFrameType::SETTINGS, SpdyFrameType::GOAWAY}));
}

TEST(OgHttp2AdapterServerTest, ServerReceivesTooLargeHeader) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kServer,
                                  .max_header_list_bytes = 64 * 1024,
                                  .max_header_field_size = 64 * 1024};
  auto adapter = OgHttp2Adapter::Create(visitor, options);

  // Due to configuration, the library will accept a maximum of 64kB of huffman
  // encoded data per header field.
  const std::string too_large_value = std::string(80 * 1024, 'q');
  const std::string frames = TestFrameSequence()
                                 .ClientPreface()
                                 .Headers(1,
                                          {{":method", "POST"},
                                           {":scheme", "https"},
                                           {":authority", "example.com"},
                                           {":path", "/this/is/request/one"},
                                           {"x-toobig", too_large_value}},
                                          /*fin=*/true)
                                 .Headers(3,
                                          {{":method", "GET"},
                                           {":scheme", "https"},
                                           {":authority", "example.com"},
                                           {":path", "/this/is/request/two"}},
                                          /*fin=*/true)
                                 .Serialize();
  testing::InSequence s;

  // Client preface (empty SETTINGS)
  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor, OnSettingsEnd());

  EXPECT_CALL(visitor, OnFrameHeader(1, _, HEADERS, END_STREAM));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(1));
  EXPECT_CALL(visitor, OnHeaderForStream(1, ":method", "POST"));
  EXPECT_CALL(visitor, OnHeaderForStream(1, ":scheme", "https"));
  EXPECT_CALL(visitor, OnHeaderForStream(1, ":authority", "example.com"));
  EXPECT_CALL(visitor, OnHeaderForStream(1, ":path", "/this/is/request/one"));
  EXPECT_CALL(visitor, OnFrameHeader(1, _, CONTINUATION, 0)).Times(3);
  EXPECT_CALL(visitor, OnFrameHeader(1, _, CONTINUATION, END_HEADERS));
  // Further header processing is skipped, as the header field is too large.

  EXPECT_CALL(visitor, OnFrameHeader(3, _, HEADERS, END_STREAM | END_HEADERS));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(3));
  EXPECT_CALL(visitor, OnHeaderForStream(3, _, _)).Times(4);
  EXPECT_CALL(visitor, OnEndHeadersForStream(3));
  EXPECT_CALL(visitor, OnEndStream(3));

  const int64_t result = adapter->ProcessBytes(frames);
  EXPECT_EQ(static_cast<int64_t>(frames.size()), result);

  EXPECT_TRUE(adapter->want_write());

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, ACK));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, ACK, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(RST_STREAM, 1, 4, 0x0));
  EXPECT_CALL(visitor,
              OnFrameSent(RST_STREAM, 1, 4, 0x0,
                          static_cast<int>(Http2ErrorCode::INTERNAL_ERROR)));
  EXPECT_CALL(visitor, OnCloseStream(1, Http2ErrorCode::HTTP2_NO_ERROR));

  int send_result = adapter->Send();
  EXPECT_EQ(0, send_result);
  EXPECT_THAT(visitor.data(),
              EqualsFrames({SpdyFrameType::SETTINGS, SpdyFrameType::SETTINGS,
                            SpdyFrameType::RST_STREAM}));
}

TEST(OgHttp2AdapterServerTest, ServerReceivesInvalidAuthority) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kServer};
  auto adapter = OgHttp2Adapter::Create(visitor, options);

  const std::string frames = TestFrameSequence()
                                 .ClientPreface()
                                 .Headers(1,
                                          {{":method", "POST"},
                                           {":scheme", "https"},
                                           {":authority", "ex|ample.com"},
                                           {":path", "/this/is/request/one"}},
                                          /*fin=*/false)
                                 .Serialize();
  testing::InSequence s;

  // Client preface (empty SETTINGS)
  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor, OnSettingsEnd());

  EXPECT_CALL(visitor, OnFrameHeader(1, _, HEADERS, 4));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(1));
  EXPECT_CALL(visitor, OnHeaderForStream(1, ":method", "POST"));
  EXPECT_CALL(visitor, OnHeaderForStream(1, ":scheme", "https"));
  EXPECT_CALL(
      visitor,
      OnInvalidFrame(1, Http2VisitorInterface::InvalidFrameError::kHttpHeader));

  const int64_t result = adapter->ProcessBytes(frames);
  EXPECT_EQ(static_cast<int64_t>(frames.size()), result);

  EXPECT_TRUE(adapter->want_write());

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0x0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x1));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x1, 0x0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(RST_STREAM, 1, 4, 0x0));
  EXPECT_CALL(visitor,
              OnFrameSent(RST_STREAM, 1, 4, 0x0,
                          static_cast<int>(Http2ErrorCode::PROTOCOL_ERROR)));
  EXPECT_CALL(visitor, OnCloseStream(1, Http2ErrorCode::HTTP2_NO_ERROR));

  int send_result = adapter->Send();
  EXPECT_EQ(0, send_result);
  EXPECT_THAT(visitor.data(),
              EqualsFrames({SpdyFrameType::SETTINGS, SpdyFrameType::SETTINGS,
                            SpdyFrameType::RST_STREAM}));
}

TEST(OgHttp2AdapterServerTest, ServerRejectsStreamData) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kServer};
  auto adapter = OgHttp2Adapter::Create(visitor, options);

  const std::string frames = TestFrameSequence()
                                 .ClientPreface()
                                 .Headers(1,
                                          {{":method", "POST"},
                                           {":scheme", "https"},
                                           {":authority", "example.com"},
                                           {":path", "/this/is/request/one"}},
                                          /*fin=*/false)
                                 .Data(1, "This is the request body.")
                                 .Headers(3,
                                          {{":method", "GET"},
                                           {":scheme", "http"},
                                           {":authority", "example.com"},
                                           {":path", "/this/is/request/two"}},
                                          /*fin=*/true)
                                 .RstStream(3, Http2ErrorCode::CANCEL)
                                 .Ping(47)
                                 .Serialize();
  testing::InSequence s;

  // Client preface (empty SETTINGS)
  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor, OnSettingsEnd());

  EXPECT_CALL(visitor, OnFrameHeader(1, _, HEADERS, 4));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(1));
  EXPECT_CALL(visitor, OnHeaderForStream(1, ":method", "POST"));
  EXPECT_CALL(visitor, OnHeaderForStream(1, ":scheme", "https"));
  EXPECT_CALL(visitor, OnHeaderForStream(1, ":authority", "example.com"));
  EXPECT_CALL(visitor, OnHeaderForStream(1, ":path", "/this/is/request/one"));
  EXPECT_CALL(visitor, OnEndHeadersForStream(1));
  EXPECT_CALL(visitor, OnFrameHeader(1, 25, DATA, 0));
  EXPECT_CALL(visitor, OnBeginDataForStream(1, 25));
  EXPECT_CALL(visitor, OnDataForStream(1, _)).WillOnce(testing::Return(false));
  EXPECT_CALL(visitor, OnConnectionError(ConnectionError::kParseError));

  const int64_t result = adapter->ProcessBytes(frames);
  EXPECT_LT(result, 0);

  EXPECT_TRUE(adapter->want_write());

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(GOAWAY, 0, _, 0x0));
  EXPECT_CALL(visitor,
              OnFrameSent(GOAWAY, 0, _, 0x0,
                          static_cast<int>(Http2ErrorCode::INTERNAL_ERROR)));

  int send_result = adapter->Send();
  // Some bytes should have been serialized.
  EXPECT_EQ(0, send_result);
  EXPECT_THAT(visitor.data(),
              EqualsFrames({SpdyFrameType::SETTINGS, SpdyFrameType::GOAWAY}));
}

// Exercises a naive mutually recursive test client and server. This test fails
// without recursion guards in OgHttp2Session.
TEST(OgHttp2AdapterInteractionTest, ClientServerInteractionTest) {
  MockHttp2Visitor client_visitor;
  auto client_adapter =
      OgHttp2Adapter::Create(client_visitor, {Perspective::kClient});
  MockHttp2Visitor server_visitor;
  auto server_adapter =
      OgHttp2Adapter::Create(server_visitor, {Perspective::kServer});

  // Feeds bytes sent from the client into the server's ProcessBytes.
  EXPECT_CALL(client_visitor, OnReadyToSend(_))
      .WillRepeatedly(
          testing::Invoke(server_adapter.get(), &OgHttp2Adapter::ProcessBytes));
  // Feeds bytes sent from the server into the client's ProcessBytes.
  EXPECT_CALL(server_visitor, OnReadyToSend(_))
      .WillRepeatedly(
          testing::Invoke(client_adapter.get(), &OgHttp2Adapter::ProcessBytes));
  // Sets up the server to respond automatically to a request from a client.
  EXPECT_CALL(server_visitor, OnEndHeadersForStream(_))
      .WillRepeatedly([&server_adapter](Http2StreamId stream_id) {
        server_adapter->SubmitResponse(
            stream_id, ToHeaders({{":status", "200"}}), nullptr);
        server_adapter->Send();
        return true;
      });
  // Sets up the client to create a new stream automatically when receiving a
  // response.
  EXPECT_CALL(client_visitor, OnEndHeadersForStream(_))
      .WillRepeatedly([&client_adapter,
                       &client_visitor](Http2StreamId stream_id) {
        if (stream_id < 10) {
          const Http2StreamId new_stream_id = stream_id + 2;
          auto body =
              absl::make_unique<TestDataFrameSource>(client_visitor, true);
          body->AppendPayload("This is an example request body.");
          body->EndData();
          const int created_stream_id = client_adapter->SubmitRequest(
              ToHeaders({{":method", "GET"},
                         {":scheme", "http"},
                         {":authority", "example.com"},
                         {":path",
                          absl::StrCat("/this/is/request/", new_stream_id)}}),
              std::move(body), nullptr);
          EXPECT_EQ(new_stream_id, created_stream_id);
          client_adapter->Send();
        }
        return true;
      });

  // Submit a request to ensure the first stream is created.
  int stream_id = client_adapter->SubmitRequest(
      ToHeaders({{":method", "POST"},
                 {":scheme", "http"},
                 {":authority", "example.com"},
                 {":path", "/this/is/request/one"}}),
      nullptr, nullptr);
  EXPECT_EQ(stream_id, 1);

  client_adapter->Send();
}

TEST(OgHttp2AdapterInteractionTest,
     ClientServerInteractionRepeatedHeaderNames) {
  DataSavingVisitor client_visitor;
  OgHttp2Adapter::Options client_options{.perspective = Perspective::kClient};
  auto client_adapter = OgHttp2Adapter::Create(client_visitor, client_options);

  const std::vector<Header> headers1 =
      ToHeaders({{":method", "GET"},
                 {":scheme", "http"},
                 {":authority", "example.com"},
                 {":path", "/this/is/request/one"},
                 {"accept", "text/plain"},
                 {"accept", "text/html"}});

  const int32_t stream_id1 =
      client_adapter->SubmitRequest(headers1, nullptr, nullptr);
  ASSERT_GT(stream_id1, 0);

  EXPECT_CALL(client_visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(client_visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  EXPECT_CALL(client_visitor, OnBeforeFrameSent(HEADERS, stream_id1, _, 0x5));
  EXPECT_CALL(client_visitor, OnFrameSent(HEADERS, stream_id1, _, 0x5, 0));
  int send_result = client_adapter->Send();
  EXPECT_EQ(0, send_result);

  DataSavingVisitor server_visitor;
  OgHttp2Adapter::Options server_options{.perspective = Perspective::kServer};
  auto server_adapter = OgHttp2Adapter::Create(server_visitor, server_options);

  testing::InSequence s;

  // Client preface (empty SETTINGS)
  EXPECT_CALL(server_visitor, OnFrameHeader(0, _, SETTINGS, 0));
  EXPECT_CALL(server_visitor, OnSettingsStart());
  EXPECT_CALL(server_visitor, OnSetting(_)).Times(testing::AnyNumber());
  EXPECT_CALL(server_visitor, OnSettingsEnd());
  // Stream 1
  EXPECT_CALL(server_visitor, OnFrameHeader(1, _, HEADERS, 5));
  EXPECT_CALL(server_visitor, OnBeginHeadersForStream(1));
  EXPECT_CALL(server_visitor, OnHeaderForStream(1, ":method", "GET"));
  EXPECT_CALL(server_visitor, OnHeaderForStream(1, ":scheme", "http"));
  EXPECT_CALL(server_visitor,
              OnHeaderForStream(1, ":authority", "example.com"));
  EXPECT_CALL(server_visitor,
              OnHeaderForStream(1, ":path", "/this/is/request/one"));
  EXPECT_CALL(server_visitor, OnHeaderForStream(1, "accept", "text/plain"));
  EXPECT_CALL(server_visitor, OnHeaderForStream(1, "accept", "text/html"));
  EXPECT_CALL(server_visitor, OnEndHeadersForStream(1));
  EXPECT_CALL(server_visitor, OnEndStream(1));

  int64_t result = server_adapter->ProcessBytes(client_visitor.data());
  EXPECT_EQ(client_visitor.data().size(), static_cast<size_t>(result));
}

TEST(OgHttp2AdapterServerTest, ServerForbidsNewStreamBelowWatermark) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kServer};
  auto adapter = OgHttp2Adapter::Create(visitor, options);

  EXPECT_EQ(0, adapter->GetHighestReceivedStreamId());

  const std::string frames = TestFrameSequence()
                                 .ClientPreface()
                                 .Headers(3,
                                          {{":method", "POST"},
                                           {":scheme", "https"},
                                           {":authority", "example.com"},
                                           {":path", "/this/is/request/one"}},
                                          /*fin=*/false)
                                 .Data(3, "This is the request body.")
                                 .Headers(1,
                                          {{":method", "GET"},
                                           {":scheme", "http"},
                                           {":authority", "example.com"},
                                           {":path", "/this/is/request/two"}},
                                          /*fin=*/true)
                                 .Serialize();
  testing::InSequence s;

  // Client preface (empty SETTINGS)
  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor, OnSettingsEnd());

  EXPECT_CALL(visitor, OnFrameHeader(3, _, HEADERS, 4));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(3));
  EXPECT_CALL(visitor, OnHeaderForStream(3, ":method", "POST"));
  EXPECT_CALL(visitor, OnHeaderForStream(3, ":scheme", "https"));
  EXPECT_CALL(visitor, OnHeaderForStream(3, ":authority", "example.com"));
  EXPECT_CALL(visitor, OnHeaderForStream(3, ":path", "/this/is/request/one"));
  EXPECT_CALL(visitor, OnEndHeadersForStream(3));
  EXPECT_CALL(visitor, OnFrameHeader(3, 25, DATA, 0));
  EXPECT_CALL(visitor, OnBeginDataForStream(3, 25));
  EXPECT_CALL(visitor, OnDataForStream(3, "This is the request body."));
  EXPECT_CALL(visitor, OnFrameHeader(1, _, HEADERS, 5));
  EXPECT_CALL(visitor, OnConnectionError(ConnectionError::kInvalidNewStreamId));

  const int64_t result = adapter->ProcessBytes(frames);
  EXPECT_EQ(static_cast<size_t>(result), frames.size());

  EXPECT_EQ(3, adapter->GetHighestReceivedStreamId());

  EXPECT_TRUE(adapter->want_write());

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(GOAWAY, 0, _, 0x0));
  EXPECT_CALL(visitor,
              OnFrameSent(GOAWAY, 0, _, 0x0,
                          static_cast<int>(Http2ErrorCode::PROTOCOL_ERROR)));

  int send_result = adapter->Send();
  // Some bytes should have been serialized.
  EXPECT_EQ(0, send_result);
  EXPECT_THAT(visitor.data(),
              EqualsFrames({SpdyFrameType::SETTINGS, SpdyFrameType::GOAWAY}));
}

TEST(OgHttp2AdapterServerTest, ServerForbidsWindowUpdateOnIdleStream) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kServer};
  auto adapter = OgHttp2Adapter::Create(visitor, options);

  EXPECT_EQ(0, adapter->GetHighestReceivedStreamId());

  const std::string frames =
      TestFrameSequence().ClientPreface().WindowUpdate(1, 42).Serialize();

  testing::InSequence s;

  // Client preface (empty SETTINGS)
  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor, OnSettingsEnd());

  EXPECT_CALL(visitor, OnFrameHeader(1, 4, WINDOW_UPDATE, 0));
  EXPECT_CALL(visitor, OnConnectionError(ConnectionError::kWrongFrameSequence));

  const int64_t result = adapter->ProcessBytes(frames);
  EXPECT_EQ(static_cast<size_t>(result), frames.size());

  EXPECT_EQ(1, adapter->GetHighestReceivedStreamId());

  EXPECT_TRUE(adapter->want_write());

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(GOAWAY, 0, _, 0x0));
  EXPECT_CALL(visitor,
              OnFrameSent(GOAWAY, 0, _, 0x0,
                          static_cast<int>(Http2ErrorCode::PROTOCOL_ERROR)));

  int send_result = adapter->Send();
  // Some bytes should have been serialized.
  EXPECT_EQ(0, send_result);
  EXPECT_THAT(visitor.data(),
              EqualsFrames({SpdyFrameType::SETTINGS, SpdyFrameType::GOAWAY}));
}

TEST(OgHttp2AdapterServerTest, ServerForbidsDataOnIdleStream) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kServer};
  auto adapter = OgHttp2Adapter::Create(visitor, options);

  EXPECT_EQ(0, adapter->GetHighestReceivedStreamId());

  const std::string frames = TestFrameSequence()
                                 .ClientPreface()
                                 .Data(1, "Sorry, out of order")
                                 .Serialize();

  testing::InSequence s;

  // Client preface (empty SETTINGS)
  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor, OnSettingsEnd());

  EXPECT_CALL(visitor, OnFrameHeader(1, _, DATA, 0));
  EXPECT_CALL(visitor, OnConnectionError(ConnectionError::kWrongFrameSequence));

  const int64_t result = adapter->ProcessBytes(frames);
  EXPECT_EQ(static_cast<size_t>(result), frames.size());

  EXPECT_EQ(1, adapter->GetHighestReceivedStreamId());

  EXPECT_TRUE(adapter->want_write());

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(GOAWAY, 0, _, 0x0));
  EXPECT_CALL(visitor,
              OnFrameSent(GOAWAY, 0, _, 0x0,
                          static_cast<int>(Http2ErrorCode::PROTOCOL_ERROR)));

  int send_result = adapter->Send();
  // Some bytes should have been serialized.
  EXPECT_EQ(0, send_result);
  EXPECT_THAT(visitor.data(),
              EqualsFrames({SpdyFrameType::SETTINGS, SpdyFrameType::GOAWAY}));
}

TEST(OgHttp2AdapterServerTest, ServerForbidsRstStreamOnIdleStream) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kServer};
  auto adapter = OgHttp2Adapter::Create(visitor, options);

  EXPECT_EQ(0, adapter->GetHighestReceivedStreamId());

  const std::string frames =
      TestFrameSequence()
          .ClientPreface()
          .RstStream(1, Http2ErrorCode::ENHANCE_YOUR_CALM)
          .Serialize();

  testing::InSequence s;

  // Client preface (empty SETTINGS)
  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor, OnSettingsEnd());

  EXPECT_CALL(visitor, OnFrameHeader(1, _, RST_STREAM, 0));
  EXPECT_CALL(visitor, OnConnectionError(ConnectionError::kWrongFrameSequence));

  const int64_t result = adapter->ProcessBytes(frames);
  EXPECT_EQ(static_cast<size_t>(result), frames.size());

  EXPECT_EQ(1, adapter->GetHighestReceivedStreamId());

  EXPECT_TRUE(adapter->want_write());

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(GOAWAY, 0, _, 0x0));
  EXPECT_CALL(visitor,
              OnFrameSent(GOAWAY, 0, _, 0x0,
                          static_cast<int>(Http2ErrorCode::PROTOCOL_ERROR)));

  int send_result = adapter->Send();
  // Some bytes should have been serialized.
  EXPECT_EQ(0, send_result);
  EXPECT_THAT(visitor.data(),
              EqualsFrames({SpdyFrameType::SETTINGS, SpdyFrameType::GOAWAY}));
}

TEST(OgHttp2AdapterServerTest, ServerForbidsNewStreamAboveStreamLimit) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kServer};
  auto adapter = OgHttp2Adapter::Create(visitor, options);
  adapter->SubmitSettings({{MAX_CONCURRENT_STREAMS, 1}});

  const std::string initial_frames =
      TestFrameSequence().ClientPreface().Serialize();

  testing::InSequence s;

  // Client preface (empty SETTINGS)
  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor, OnSettingsEnd());

  const int64_t initial_result = adapter->ProcessBytes(initial_frames);
  EXPECT_EQ(static_cast<size_t>(initial_result), initial_frames.size());

  EXPECT_TRUE(adapter->want_write());

  // Server initial SETTINGS (with MAX_CONCURRENT_STREAMS) and SETTINGS ack.
  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, 6, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, 6, 0x0, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, 0, 0x1));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, 0, 0x1, 0));

  int send_result = adapter->Send();
  EXPECT_EQ(0, send_result);
  EXPECT_THAT(visitor.data(),
              EqualsFrames({SpdyFrameType::SETTINGS, SpdyFrameType::SETTINGS}));
  visitor.Clear();

  // Let the client send a SETTINGS ack and then attempt to open more than the
  // advertised number of streams. The overflow stream should be rejected.
  const std::string stream_frames =
      TestFrameSequence()
          .SettingsAck()
          .Headers(1,
                   {{":method", "GET"},
                    {":scheme", "https"},
                    {":authority", "example.com"},
                    {":path", "/this/is/request/one"}},
                   /*fin=*/true)
          .Headers(3,
                   {{":method", "GET"},
                    {":scheme", "http"},
                    {":authority", "example.com"},
                    {":path", "/this/is/request/two"}},
                   /*fin=*/true)
          .Serialize();

  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0x1));
  EXPECT_CALL(visitor, OnSettingsAck());
  EXPECT_CALL(visitor, OnFrameHeader(1, _, HEADERS, 0x5));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(1));
  EXPECT_CALL(visitor, OnHeaderForStream(1, _, _)).Times(4);
  EXPECT_CALL(visitor, OnEndHeadersForStream(1));
  EXPECT_CALL(visitor, OnEndStream(1));
  EXPECT_CALL(visitor, OnFrameHeader(3, _, HEADERS, 0x5));
  EXPECT_CALL(
      visitor,
      OnInvalidFrame(3, Http2VisitorInterface::InvalidFrameError::kProtocol));
  // The oghttp2 stack also signals the error via OnConnectionError().
  EXPECT_CALL(visitor,
              OnConnectionError(Http2VisitorInterface::ConnectionError::
                                    kExceededMaxConcurrentStreams));

  const int64_t stream_result = adapter->ProcessBytes(stream_frames);
  EXPECT_EQ(static_cast<size_t>(stream_result), stream_frames.size());

  // The server should send a GOAWAY for this error, even though
  // OnInvalidFrame() returns true.
  EXPECT_TRUE(adapter->want_write());
  EXPECT_CALL(visitor, OnBeforeFrameSent(GOAWAY, 0, _, 0x0));
  EXPECT_CALL(visitor,
              OnFrameSent(GOAWAY, 0, _, 0x0,
                          static_cast<int>(Http2ErrorCode::PROTOCOL_ERROR)));

  send_result = adapter->Send();
  EXPECT_EQ(0, send_result);
  EXPECT_THAT(visitor.data(), EqualsFrames({SpdyFrameType::GOAWAY}));
}

TEST(OgHttp2AdapterServerTest,
     ServerRstStreamsNewStreamAboveStreamLimitBeforeAck) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kServer};
  auto adapter = OgHttp2Adapter::Create(visitor, options);
  adapter->SubmitSettings({{MAX_CONCURRENT_STREAMS, 1}});

  const std::string initial_frames =
      TestFrameSequence().ClientPreface().Serialize();

  testing::InSequence s;

  // Client preface (empty SETTINGS)
  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor, OnSettingsEnd());

  const int64_t initial_result = adapter->ProcessBytes(initial_frames);
  EXPECT_EQ(static_cast<size_t>(initial_result), initial_frames.size());

  EXPECT_TRUE(adapter->want_write());

  // Server initial SETTINGS (with MAX_CONCURRENT_STREAMS) and SETTINGS ack.
  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, 6, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, 6, 0x0, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, 0, 0x1));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, 0, 0x1, 0));

  int send_result = adapter->Send();
  EXPECT_EQ(0, send_result);
  EXPECT_THAT(visitor.data(),
              EqualsFrames({SpdyFrameType::SETTINGS, SpdyFrameType::SETTINGS}));
  visitor.Clear();

  // Let the client avoid sending a SETTINGS ack and attempt to open more than
  // the advertised number of streams. The server should still reject the
  // overflow stream, albeit with RST_STREAM REFUSED_STREAM instead of GOAWAY.
  const std::string stream_frames =
      TestFrameSequence()
          .Headers(1,
                   {{":method", "GET"},
                    {":scheme", "https"},
                    {":authority", "example.com"},
                    {":path", "/this/is/request/one"}},
                   /*fin=*/true)
          .Headers(3,
                   {{":method", "GET"},
                    {":scheme", "http"},
                    {":authority", "example.com"},
                    {":path", "/this/is/request/two"}},
                   /*fin=*/true)
          .Serialize();

  EXPECT_CALL(visitor, OnFrameHeader(1, _, HEADERS, 0x5));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(1));
  EXPECT_CALL(visitor, OnHeaderForStream(1, _, _)).Times(4);
  EXPECT_CALL(visitor, OnEndHeadersForStream(1));
  EXPECT_CALL(visitor, OnEndStream(1));
  EXPECT_CALL(visitor, OnFrameHeader(3, _, HEADERS, 0x5));
  EXPECT_CALL(visitor,
              OnInvalidFrame(
                  3, Http2VisitorInterface::InvalidFrameError::kRefusedStream));

  const int64_t stream_result = adapter->ProcessBytes(stream_frames);
  EXPECT_EQ(static_cast<size_t>(stream_result), stream_frames.size());

  // The server sends a RST_STREAM for the offending stream.
  EXPECT_TRUE(adapter->want_write());
  EXPECT_CALL(visitor, OnBeforeFrameSent(RST_STREAM, 3, _, 0x0));
  EXPECT_CALL(visitor,
              OnFrameSent(RST_STREAM, 3, _, 0x0,
                          static_cast<int>(Http2ErrorCode::REFUSED_STREAM)));

  send_result = adapter->Send();
  EXPECT_EQ(0, send_result);
  EXPECT_THAT(visitor.data(), EqualsFrames({SpdyFrameType::RST_STREAM}));
}

TEST(OgHttp2AdapterServerTest, ServerForbidsProtocolPseudoheaderBeforeAck) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kServer,
                                  .allow_extended_connect = false};
  auto adapter = OgHttp2Adapter::Create(visitor, options);

  const std::string initial_frames =
      TestFrameSequence().ClientPreface().Serialize();

  testing::InSequence s;

  // Client preface (empty SETTINGS)
  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor, OnSettingsEnd());

  const int64_t initial_result = adapter->ProcessBytes(initial_frames);
  EXPECT_EQ(static_cast<size_t>(initial_result), initial_frames.size());

  // The client attempts to send a CONNECT request with the `:protocol`
  // pseudoheader before receiving the server's SETTINGS frame.
  const std::string stream1_frames =
      TestFrameSequence()
          .Headers(1,
                   {{":method", "CONNECT"},
                    {":scheme", "https"},
                    {":authority", "example.com"},
                    {":path", "/this/is/request/one"},
                    {":protocol", "websocket"}},
                   /*fin=*/true)
          .Serialize();

  EXPECT_CALL(visitor, OnFrameHeader(1, _, HEADERS, 0x5));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(1));
  EXPECT_CALL(visitor, OnHeaderForStream(1, _, _)).Times(5);
  EXPECT_CALL(visitor,
              OnInvalidFrame(
                  1, Http2VisitorInterface::InvalidFrameError::kHttpMessaging));

  int64_t stream_result = adapter->ProcessBytes(stream1_frames);
  EXPECT_EQ(static_cast<size_t>(stream_result), stream1_frames.size());

  // Server initial SETTINGS and SETTINGS ack.
  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, 0, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, 0, 0x0, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, 0, 0x1));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, 0, 0x1, 0));

  // The server sends a RST_STREAM for the offending stream.
  EXPECT_CALL(visitor, OnBeforeFrameSent(RST_STREAM, 1, _, 0x0));
  EXPECT_CALL(visitor,
              OnFrameSent(RST_STREAM, 1, _, 0x0,
                          static_cast<int>(Http2ErrorCode::PROTOCOL_ERROR)));
  EXPECT_CALL(visitor, OnCloseStream(1, Http2ErrorCode::HTTP2_NO_ERROR));

  // Server settings with ENABLE_CONNECT_PROTOCOL.
  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, 6, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, 6, 0x0, 0));

  adapter->SubmitSettings({{ENABLE_CONNECT_PROTOCOL, 1}});
  int send_result = adapter->Send();
  EXPECT_EQ(0, send_result);
  EXPECT_THAT(
      visitor.data(),
      EqualsFrames({SpdyFrameType::SETTINGS, SpdyFrameType::SETTINGS,
                    SpdyFrameType::RST_STREAM, SpdyFrameType::SETTINGS}));
  visitor.Clear();

  // The client attempts to send a CONNECT request with the `:protocol`
  // pseudoheader before acking the server's SETTINGS frame.
  const std::string stream3_frames =
      TestFrameSequence()
          .Headers(3,
                   {{":method", "CONNECT"},
                    {":scheme", "https"},
                    {":authority", "example.com"},
                    {":path", "/this/is/request/two"},
                    {":protocol", "websocket"}},
                   /*fin=*/true)
          .Serialize();

  // After sending SETTINGS with `ENABLE_CONNECT_PROTOCOL`, oghttp2 matches
  // nghttp2 in allowing this, even though the `allow_extended_connect` option
  // is false.
  EXPECT_CALL(visitor, OnFrameHeader(3, _, HEADERS, 0x5));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(3));
  EXPECT_CALL(visitor, OnHeaderForStream(3, _, _)).Times(5);
  EXPECT_CALL(visitor, OnEndHeadersForStream(3));
  EXPECT_CALL(visitor, OnEndStream(3));

  stream_result = adapter->ProcessBytes(stream3_frames);
  EXPECT_EQ(static_cast<size_t>(stream_result), stream3_frames.size());

  EXPECT_FALSE(adapter->want_write());
}

TEST(OgHttp2AdapterServerTest, ServerAllowsProtocolPseudoheaderAfterAck) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kServer};
  auto adapter = OgHttp2Adapter::Create(visitor, options);
  adapter->SubmitSettings({{ENABLE_CONNECT_PROTOCOL, 1}});

  const std::string initial_frames =
      TestFrameSequence().ClientPreface().Serialize();

  testing::InSequence s;

  // Client preface (empty SETTINGS)
  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor, OnSettingsEnd());

  const int64_t initial_result = adapter->ProcessBytes(initial_frames);
  EXPECT_EQ(static_cast<size_t>(initial_result), initial_frames.size());

  // Server initial SETTINGS (with ENABLE_CONNECT_PROTOCOL) and SETTINGS ack.
  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, 6, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, 6, 0x0, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, 0, 0x1));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, 0, 0x1, 0));

  int send_result = adapter->Send();
  EXPECT_EQ(0, send_result);
  visitor.Clear();

  // The client attempts to send a CONNECT request with the `:protocol`
  // pseudoheader after acking the server's SETTINGS frame.
  const std::string stream_frames =
      TestFrameSequence()
          .SettingsAck()
          .Headers(1,
                   {{":method", "CONNECT"},
                    {":scheme", "https"},
                    {":authority", "example.com"},
                    {":path", "/this/is/request/one"},
                    {":protocol", "websocket"}},
                   /*fin=*/true)
          .Serialize();

  EXPECT_CALL(visitor, OnFrameHeader(0, _, SETTINGS, 0x1));
  EXPECT_CALL(visitor, OnSettingsAck());
  EXPECT_CALL(visitor, OnFrameHeader(1, _, HEADERS, 0x5));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(1));
  EXPECT_CALL(visitor, OnHeaderForStream(1, _, _)).Times(5);
  EXPECT_CALL(visitor, OnEndHeadersForStream(1));
  EXPECT_CALL(visitor, OnEndStream(1));

  const int64_t stream_result = adapter->ProcessBytes(stream_frames);
  EXPECT_EQ(static_cast<size_t>(stream_result), stream_frames.size());

  EXPECT_FALSE(adapter->want_write());
}

TEST(OgHttp2AdapterServerTest, SkipsSendingFramesForRejectedStream) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kServer};
  auto adapter = OgHttp2Adapter::Create(visitor, options);

  const std::string initial_frames =
      TestFrameSequence()
          .ClientPreface()
          .Headers(1,
                   {{":method", "GET"},
                    {":scheme", "http"},
                    {":authority", "example.com"},
                    {":path", "/this/is/request/one"}},
                   /*fin=*/true)
          .Serialize();

  testing::InSequence s;

  // Client preface (empty SETTINGS)
  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor, OnSettingsEnd());
  EXPECT_CALL(visitor, OnFrameHeader(1, _, HEADERS, 0x5));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(1));
  EXPECT_CALL(visitor, OnHeaderForStream(1, _, _)).Times(4);
  EXPECT_CALL(visitor, OnEndHeadersForStream(1));
  EXPECT_CALL(visitor, OnEndStream(1));

  const int64_t initial_result = adapter->ProcessBytes(initial_frames);
  EXPECT_EQ(static_cast<size_t>(initial_result), initial_frames.size());

  auto body = absl::make_unique<TestDataFrameSource>(visitor, true);
  body->AppendPayload("Here is some data, which will be completely ignored!");

  int submit_result = adapter->SubmitResponse(
      1, ToHeaders({{":status", "200"}}), std::move(body));
  ASSERT_EQ(0, submit_result);

  auto source = absl::make_unique<TestMetadataSource>(ToHeaderBlock(ToHeaders(
      {{"query-cost", "is too darn high"}, {"secret-sauce", "hollandaise"}})));
  adapter->SubmitMetadata(1, 16384u, std::move(source));

  adapter->SubmitWindowUpdate(1, 1024);
  adapter->SubmitRst(1, Http2ErrorCode::INTERNAL_ERROR);

  // Server initial SETTINGS and SETTINGS ack.
  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, 0, 0x1));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, 0, 0x1, 0));

  // The server sends a RST_STREAM for the offending stream.
  // The response HEADERS, DATA and WINDOW_UPDATE are all ignored.
  EXPECT_CALL(visitor, OnBeforeFrameSent(RST_STREAM, 1, _, 0x0));
  EXPECT_CALL(visitor,
              OnFrameSent(RST_STREAM, 1, _, 0x0,
                          static_cast<int>(Http2ErrorCode::INTERNAL_ERROR)));
  EXPECT_CALL(visitor, OnCloseStream(1, Http2ErrorCode::HTTP2_NO_ERROR));

  int send_result = adapter->Send();
  EXPECT_EQ(0, send_result);
  EXPECT_THAT(visitor.data(),
              EqualsFrames({SpdyFrameType::SETTINGS, SpdyFrameType::SETTINGS,
                            SpdyFrameType::RST_STREAM}));
}

TEST(OgHttpAdapterServerTest, ServerStartsShutdown) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kServer};
  auto adapter = OgHttp2Adapter::Create(visitor, options);

  EXPECT_FALSE(adapter->want_write());

  adapter->SubmitShutdownNotice();
  EXPECT_TRUE(adapter->want_write());

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(GOAWAY, 0, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(GOAWAY, 0, _, 0x0, 0));

  int result = adapter->Send();
  EXPECT_EQ(0, result);
  EXPECT_THAT(visitor.data(),
              EqualsFrames({SpdyFrameType::SETTINGS, SpdyFrameType::GOAWAY}));
}

TEST(OgHttp2AdapterServerTest, ServerStartsShutdownAfterGoaway) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kServer};
  auto adapter = OgHttp2Adapter::Create(visitor, options);

  EXPECT_FALSE(adapter->want_write());

  adapter->SubmitGoAway(1, Http2ErrorCode::HTTP2_NO_ERROR,
                        "and don't come back!");
  EXPECT_TRUE(adapter->want_write());

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(GOAWAY, 0, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(GOAWAY, 0, _, 0x0, 0));

  int result = adapter->Send();
  EXPECT_EQ(0, result);
  EXPECT_THAT(visitor.data(),
              EqualsFrames({SpdyFrameType::SETTINGS, SpdyFrameType::GOAWAY}));

  // No-op, since a GOAWAY has previously been enqueued.
  adapter->SubmitShutdownNotice();
  EXPECT_FALSE(adapter->want_write());
}

// Verifies that a connection-level processing error results in repeatedly
// returning a positive value for ProcessBytes() to mark all data as consumed
// when the blackhole option is enabled.
TEST(OgHttp2AdapterServerTest, ConnectionErrorWithBlackholingData) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kServer,
                                  .blackhole_data_on_connection_error = true};
  auto adapter = OgHttp2Adapter::Create(visitor, options);

  const std::string frames =
      TestFrameSequence().ClientPreface().WindowUpdate(1, 42).Serialize();

  testing::InSequence s;

  // Client preface (empty SETTINGS)
  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor, OnSettingsEnd());

  EXPECT_CALL(visitor, OnFrameHeader(1, 4, WINDOW_UPDATE, 0));
  EXPECT_CALL(visitor, OnConnectionError(ConnectionError::kWrongFrameSequence));

  const int64_t result = adapter->ProcessBytes(frames);
  EXPECT_EQ(static_cast<size_t>(result), frames.size());

  // Ask the connection to process more bytes. Because the option is enabled,
  // the data should be marked as consumed.
  const std::string next_frame = TestFrameSequence().Ping(42).Serialize();
  const int64_t next_result = adapter->ProcessBytes(next_frame);
  EXPECT_EQ(static_cast<size_t>(next_result), next_frame.size());
}

// Verifies that a connection-level processing error results in returning a
// negative value for ProcessBytes() when the blackhole option is disabled.
TEST(OgHttp2AdapterServerTest, ConnectionErrorWithoutBlackholingData) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kServer,
                                  .blackhole_data_on_connection_error = false};
  auto adapter = OgHttp2Adapter::Create(visitor, options);

  const std::string frames =
      TestFrameSequence().ClientPreface().WindowUpdate(1, 42).Serialize();

  testing::InSequence s;

  // Client preface (empty SETTINGS)
  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor, OnSettingsEnd());

  EXPECT_CALL(visitor, OnFrameHeader(1, 4, WINDOW_UPDATE, 0));
  EXPECT_CALL(visitor, OnConnectionError(ConnectionError::kWrongFrameSequence));

  const int64_t result = adapter->ProcessBytes(frames);
  EXPECT_LT(result, 0);

  // Ask the connection to process more bytes. Because the option is disabled,
  // ProcessBytes() should continue to return an error.
  const std::string next_frame = TestFrameSequence().Ping(42).Serialize();
  const int64_t next_result = adapter->ProcessBytes(next_frame);
  EXPECT_LT(next_result, 0);
}

TEST(OgHttp2AdapterServerTest, ServerDoesNotSendFramesAfterImmediateGoAway) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kServer};
  auto adapter = OgHttp2Adapter::Create(visitor, options);

  // Submit a custom initial SETTINGS frame with one setting.
  adapter->SubmitSettings({{HEADER_TABLE_SIZE, 100u}});

  const std::string frames = TestFrameSequence()
                                 .ClientPreface()
                                 .Headers(1,
                                          {{":method", "GET"},
                                           {":scheme", "https"},
                                           {":authority", "example.com"},
                                           {":path", "/this/is/request/one"}},
                                          /*fin=*/true)
                                 .Serialize();
  testing::InSequence s;

  // Client preface (empty SETTINGS)
  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor, OnSettingsEnd());
  // Stream 1
  EXPECT_CALL(visitor, OnFrameHeader(1, _, HEADERS, 0x5));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(1));
  EXPECT_CALL(visitor, OnHeaderForStream(1, _, _)).Times(4);
  EXPECT_CALL(visitor, OnEndHeadersForStream(1));
  EXPECT_CALL(visitor, OnEndStream(1));

  const int64_t read_result = adapter->ProcessBytes(frames);
  EXPECT_EQ(static_cast<size_t>(read_result), frames.size());

  // Submit a response for the stream.
  auto body = absl::make_unique<TestDataFrameSource>(visitor, true);
  body->AppendPayload("This data is doomed to never be written.");
  int submit_result = adapter->SubmitResponse(
      1, ToHeaders({{":status", "200"}}), std::move(body));
  ASSERT_EQ(0, submit_result);

  // Submit a WINDOW_UPDATE frame.
  adapter->SubmitWindowUpdate(kConnectionStreamId, 42);

  // Submit another SETTINGS frame.
  adapter->SubmitSettings({});

  // Submit some metadata.
  auto source = absl::make_unique<TestMetadataSource>(ToHeaderBlock(ToHeaders(
      {{"query-cost", "is too darn high"}, {"secret-sauce", "hollandaise"}})));
  adapter->SubmitMetadata(1, 16384u, std::move(source));

  EXPECT_TRUE(adapter->want_write());

  // Trigger a connection error. Only the response headers will be written.
  const std::string connection_error_frames =
      TestFrameSequence().WindowUpdate(3, 42).Serialize();

  EXPECT_CALL(visitor, OnFrameHeader(3, 4, WINDOW_UPDATE, 0));
  EXPECT_CALL(visitor, OnConnectionError(ConnectionError::kWrongFrameSequence));

  const int64_t result = adapter->ProcessBytes(connection_error_frames);
  EXPECT_EQ(static_cast<size_t>(result), connection_error_frames.size());

  EXPECT_TRUE(adapter->want_write());

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, 6, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, 6, 0x0, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(GOAWAY, 0, _, 0x0));
  EXPECT_CALL(visitor,
              OnFrameSent(GOAWAY, 0, _, 0x0,
                          static_cast<int>(Http2ErrorCode::PROTOCOL_ERROR)));

  int send_result = adapter->Send();
  // Some bytes should have been serialized.
  EXPECT_EQ(0, send_result);
  EXPECT_THAT(visitor.data(),
              EqualsFrames({SpdyFrameType::SETTINGS, SpdyFrameType::GOAWAY}));
  visitor.Clear();

  // Try to submit more frames for writing. They should not be written.
  adapter->SubmitPing(42);
  // TODO(diannahu): Enable the below expectation.
  // EXPECT_FALSE(adapter->want_write());
  send_result = adapter->Send();
  EXPECT_EQ(0, send_result);
  EXPECT_THAT(visitor.data(), testing::IsEmpty());
}

TEST(OgHttp2AdapterServerTest, ServerHandlesContentLength) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kServer};
  auto adapter = OgHttp2Adapter::Create(visitor, options);

  testing::InSequence s;

  const std::string stream_frames =
      TestFrameSequence()
          .ClientPreface()
          .Headers(1, {{":method", "GET"},
                       {":scheme", "https"},
                       {":authority", "example.com"},
                       {":path", "/this/is/request/one"},
                       {"content-length", "2"}})
          .Data(1, "hi", /*fin=*/true)
          .Headers(3,
                   {{":method", "GET"},
                    {":scheme", "https"},
                    {":authority", "example.com"},
                    {":path", "/this/is/request/three"},
                    {"content-length", "nan"}},
                   /*fin=*/true)
          .Serialize();

  // Client preface (empty SETTINGS)
  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor, OnSettingsEnd());

  // Stream 1: content-length is correct
  EXPECT_CALL(visitor, OnFrameHeader(1, _, HEADERS, 4));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(1));
  EXPECT_CALL(visitor, OnHeaderForStream(1, _, _)).Times(5);
  EXPECT_CALL(visitor, OnEndHeadersForStream(1));
  EXPECT_CALL(visitor, OnFrameHeader(1, _, DATA, 1));
  EXPECT_CALL(visitor, OnBeginDataForStream(1, 2));
  EXPECT_CALL(visitor, OnDataForStream(1, "hi"));
  EXPECT_CALL(visitor, OnEndStream(1));

  // Stream 3: content-length is not a number
  EXPECT_CALL(visitor, OnFrameHeader(3, _, HEADERS, 5));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(3));
  EXPECT_CALL(visitor, OnHeaderForStream(3, _, _)).Times(4);
  EXPECT_CALL(
      visitor,
      OnInvalidFrame(3, Http2VisitorInterface::InvalidFrameError::kHttpHeader));

  const int64_t stream_result = adapter->ProcessBytes(stream_frames);
  EXPECT_EQ(stream_frames.size(), static_cast<size_t>(stream_result));

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x1));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x1, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(RST_STREAM, 3, _, 0x0));
  EXPECT_CALL(visitor,
              OnFrameSent(RST_STREAM, 3, _, 0x0,
                          static_cast<int>(Http2ErrorCode::PROTOCOL_ERROR)));
  EXPECT_CALL(visitor, OnCloseStream(3, Http2ErrorCode::HTTP2_NO_ERROR));

  EXPECT_TRUE(adapter->want_write());
  int result = adapter->Send();
  EXPECT_EQ(0, result);
  EXPECT_THAT(visitor.data(),
              EqualsFrames({SpdyFrameType::SETTINGS, SpdyFrameType::SETTINGS,
                            SpdyFrameType::RST_STREAM}));
}

TEST(OgHttp2AdapterServerTest, ServerHandlesContentLengthMismatch) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kServer};
  auto adapter = OgHttp2Adapter::Create(visitor, options);

  testing::InSequence s;

  const std::string stream_frames =
      TestFrameSequence()
          .ClientPreface()
          .Headers(1, {{":method", "GET"},
                       {":scheme", "https"},
                       {":authority", "example.com"},
                       {":path", "/this/is/request/two"},
                       {"content-length", "2"}})
          .Data(1, "h", /*fin=*/true)
          .Headers(3, {{":method", "GET"},
                       {":scheme", "https"},
                       {":authority", "example.com"},
                       {":path", "/this/is/request/three"},
                       {"content-length", "2"}})
          .Data(3, "howdy", /*fin=*/true)
          .Headers(5,
                   {{":method", "GET"},
                    {":scheme", "https"},
                    {":authority", "example.com"},
                    {":path", "/this/is/request/four"},
                    {"content-length", "2"}},
                   /*fin=*/true)
          .Headers(7,
                   {{":method", "GET"},
                    {":scheme", "https"},
                    {":authority", "example.com"},
                    {":path", "/this/is/request/four"},
                    {"content-length", "2"}},
                   /*fin=*/false)
          .Data(7, "h", /*fin=*/false)
          .Headers(7, {{"extra-info", "Trailers with content-length mismatch"}},
                   /*fin=*/true)
          .Serialize();

  // Client preface (empty SETTINGS)
  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor, OnSettingsEnd());

  // Stream 1: content-length is larger than actual data
  // All data is delivered to the visitor. Note that neither oghttp2 nor
  // nghttp2 delivers OnInvalidFrame().
  EXPECT_CALL(visitor, OnFrameHeader(1, _, HEADERS, 4));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(1));
  EXPECT_CALL(visitor, OnHeaderForStream(1, _, _)).Times(5);
  EXPECT_CALL(visitor, OnEndHeadersForStream(1));
  EXPECT_CALL(visitor, OnFrameHeader(1, _, DATA, 1));
  EXPECT_CALL(visitor, OnBeginDataForStream(1, 1));
  EXPECT_CALL(visitor, OnDataForStream(1, "h"));

  // Stream 3: content-length is smaller than actual data
  // The beginning of data is delivered to the visitor, but not the actual data.
  // Again, neither oghttp2 nor nghttp2 delivers OnInvalidFrame().
  EXPECT_CALL(visitor, OnFrameHeader(3, _, HEADERS, 4));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(3));
  EXPECT_CALL(visitor, OnHeaderForStream(3, _, _)).Times(5);
  EXPECT_CALL(visitor, OnEndHeadersForStream(3));
  EXPECT_CALL(visitor, OnFrameHeader(3, _, DATA, 1));
  EXPECT_CALL(visitor, OnBeginDataForStream(3, 5));

  // Stream 5: content-length is invalid and HEADERS ends the stream
  // Only oghttp2 invokes OnEndHeadersForStream(). Only nghttp2 invokes
  // OnInvalidFrame().
  EXPECT_CALL(visitor, OnFrameHeader(5, _, HEADERS, 5));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(5));
  EXPECT_CALL(visitor, OnHeaderForStream(5, _, _)).Times(5);
  EXPECT_CALL(visitor, OnEndHeadersForStream(5));

  // Stream 7: content-length is invalid and trailers end the stream
  // Only oghttp2 invokes OnEndHeadersForStream(). Only nghttp2 invokes
  // OnInvalidFrame().
  EXPECT_CALL(visitor, OnFrameHeader(7, _, HEADERS, 4));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(7));
  EXPECT_CALL(visitor, OnHeaderForStream(7, _, _)).Times(5);
  EXPECT_CALL(visitor, OnEndHeadersForStream(7));
  EXPECT_CALL(visitor, OnFrameHeader(7, _, DATA, 0));
  EXPECT_CALL(visitor, OnBeginDataForStream(7, 1));
  EXPECT_CALL(visitor, OnDataForStream(7, "h"));
  EXPECT_CALL(visitor, OnFrameHeader(7, _, HEADERS, 5));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(7));
  EXPECT_CALL(visitor, OnHeaderForStream(7, _, _));
  EXPECT_CALL(visitor, OnEndHeadersForStream(7));

  const int64_t stream_result = adapter->ProcessBytes(stream_frames);
  EXPECT_EQ(stream_frames.size(), static_cast<size_t>(stream_result));

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x1));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x1, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(RST_STREAM, 1, _, 0x0));
  EXPECT_CALL(visitor,
              OnFrameSent(RST_STREAM, 1, _, 0x0,
                          static_cast<int>(Http2ErrorCode::PROTOCOL_ERROR)));
  EXPECT_CALL(visitor, OnCloseStream(1, Http2ErrorCode::HTTP2_NO_ERROR));
  EXPECT_CALL(visitor, OnBeforeFrameSent(RST_STREAM, 3, _, 0x0));
  EXPECT_CALL(visitor,
              OnFrameSent(RST_STREAM, 3, _, 0x0,
                          static_cast<int>(Http2ErrorCode::PROTOCOL_ERROR)));
  EXPECT_CALL(visitor, OnCloseStream(3, Http2ErrorCode::HTTP2_NO_ERROR));
  EXPECT_CALL(visitor, OnBeforeFrameSent(RST_STREAM, 5, _, 0x0));
  EXPECT_CALL(visitor,
              OnFrameSent(RST_STREAM, 5, _, 0x0,
                          static_cast<int>(Http2ErrorCode::PROTOCOL_ERROR)));
  EXPECT_CALL(visitor, OnCloseStream(5, Http2ErrorCode::HTTP2_NO_ERROR));
  EXPECT_CALL(visitor, OnBeforeFrameSent(RST_STREAM, 7, _, 0x0));
  EXPECT_CALL(visitor,
              OnFrameSent(RST_STREAM, 7, _, 0x0,
                          static_cast<int>(Http2ErrorCode::PROTOCOL_ERROR)));
  EXPECT_CALL(visitor, OnCloseStream(7, Http2ErrorCode::HTTP2_NO_ERROR));

  EXPECT_TRUE(adapter->want_write());
  int result = adapter->Send();
  EXPECT_EQ(0, result);
  EXPECT_THAT(
      visitor.data(),
      EqualsFrames({SpdyFrameType::SETTINGS, SpdyFrameType::SETTINGS,
                    SpdyFrameType::RST_STREAM, SpdyFrameType::RST_STREAM,
                    SpdyFrameType::RST_STREAM, SpdyFrameType::RST_STREAM}));
}

TEST(OgHttp2AdapterServerTest, ServerHandlesAsteriskPathForOptions) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kServer};
  auto adapter = OgHttp2Adapter::Create(visitor, options);

  testing::InSequence s;

  const std::string stream_frames = TestFrameSequence()
                                        .ClientPreface()
                                        .Headers(1,
                                                 {{":scheme", "https"},
                                                  {":authority", "example.com"},
                                                  {":path", "*"},
                                                  {":method", "OPTIONS"}},
                                                 /*fin=*/true)
                                        .Serialize();

  // Client preface (empty SETTINGS)
  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor, OnSettingsEnd());

  EXPECT_CALL(visitor, OnFrameHeader(1, _, HEADERS, 5));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(1));
  EXPECT_CALL(visitor, OnHeaderForStream(1, _, _)).Times(4);
  EXPECT_CALL(visitor, OnEndHeadersForStream(1));
  EXPECT_CALL(visitor, OnEndStream(1));

  const int64_t stream_result = adapter->ProcessBytes(stream_frames);
  EXPECT_EQ(stream_frames.size(), static_cast<size_t>(stream_result));

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x1));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x1, 0));

  EXPECT_TRUE(adapter->want_write());
  int result = adapter->Send();
  EXPECT_EQ(0, result);
  EXPECT_THAT(visitor.data(),
              EqualsFrames({SpdyFrameType::SETTINGS, SpdyFrameType::SETTINGS}));
}

TEST(OgHttp2AdapterServerTest, ServerHandlesInvalidPath) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kServer};
  auto adapter = OgHttp2Adapter::Create(visitor, options);

  testing::InSequence s;

  const std::string stream_frames =
      TestFrameSequence()
          .ClientPreface()
          .Headers(1,
                   {{":scheme", "https"},
                    {":authority", "example.com"},
                    {":path", "*"},
                    {":method", "GET"}},
                   /*fin=*/true)
          .Headers(3,
                   {{":scheme", "https"},
                    {":authority", "example.com"},
                    {":path", "other/non/slash/starter"},
                    {":method", "GET"}},
                   /*fin=*/true)
          .Headers(5,
                   {{":scheme", "https"},
                    {":authority", "example.com"},
                    {":path", ""},
                    {":method", "GET"}},
                   /*fin=*/true)
          .Serialize();

  // Client preface (empty SETTINGS)
  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor, OnSettingsEnd());

  EXPECT_CALL(visitor, OnFrameHeader(1, _, HEADERS, 5));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(1));
  EXPECT_CALL(visitor, OnHeaderForStream(1, _, _)).Times(4);
  EXPECT_CALL(visitor,
              OnInvalidFrame(
                  1, Http2VisitorInterface::InvalidFrameError::kHttpMessaging));

  EXPECT_CALL(visitor, OnFrameHeader(3, _, HEADERS, 5));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(3));
  EXPECT_CALL(visitor, OnHeaderForStream(3, _, _)).Times(4);
  EXPECT_CALL(visitor,
              OnInvalidFrame(
                  3, Http2VisitorInterface::InvalidFrameError::kHttpMessaging));

  EXPECT_CALL(visitor, OnFrameHeader(5, _, HEADERS, 5));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(5));
  EXPECT_CALL(visitor, OnHeaderForStream(5, _, _)).Times(2);
  EXPECT_CALL(
      visitor,
      OnInvalidFrame(5, Http2VisitorInterface::InvalidFrameError::kHttpHeader));

  const int64_t stream_result = adapter->ProcessBytes(stream_frames);
  EXPECT_EQ(stream_frames.size(), static_cast<size_t>(stream_result));

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x1));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x1, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(RST_STREAM, 1, _, 0x0));
  EXPECT_CALL(visitor,
              OnFrameSent(RST_STREAM, 1, _, 0x0,
                          static_cast<int>(Http2ErrorCode::PROTOCOL_ERROR)));
  EXPECT_CALL(visitor, OnCloseStream(1, Http2ErrorCode::HTTP2_NO_ERROR));
  EXPECT_CALL(visitor, OnBeforeFrameSent(RST_STREAM, 3, _, 0x0));
  EXPECT_CALL(visitor,
              OnFrameSent(RST_STREAM, 3, _, 0x0,
                          static_cast<int>(Http2ErrorCode::PROTOCOL_ERROR)));
  EXPECT_CALL(visitor, OnCloseStream(3, Http2ErrorCode::HTTP2_NO_ERROR));
  EXPECT_CALL(visitor, OnBeforeFrameSent(RST_STREAM, 5, _, 0x0));
  EXPECT_CALL(visitor,
              OnFrameSent(RST_STREAM, 5, _, 0x0,
                          static_cast<int>(Http2ErrorCode::PROTOCOL_ERROR)));
  EXPECT_CALL(visitor, OnCloseStream(5, Http2ErrorCode::HTTP2_NO_ERROR));

  EXPECT_TRUE(adapter->want_write());
  int result = adapter->Send();
  EXPECT_EQ(0, result);
  EXPECT_THAT(
      visitor.data(),
      EqualsFrames({SpdyFrameType::SETTINGS, SpdyFrameType::SETTINGS,
                    SpdyFrameType::RST_STREAM, SpdyFrameType::RST_STREAM,
                    SpdyFrameType::RST_STREAM}));
}

TEST(OgHttp2AdapterServerTest, ServerHandlesTeHeader) {
  DataSavingVisitor visitor;
  OgHttp2Adapter::Options options{.perspective = Perspective::kServer};
  auto adapter = OgHttp2Adapter::Create(visitor, options);

  testing::InSequence s;

  const std::string stream_frames = TestFrameSequence()
                                        .ClientPreface()
                                        .Headers(1,
                                                 {{":scheme", "https"},
                                                  {":authority", "example.com"},
                                                  {":path", "/"},
                                                  {":method", "GET"},
                                                  {"te", "trailers"}},
                                                 /*fin=*/true)
                                        .Headers(3,
                                                 {{":scheme", "https"},
                                                  {":authority", "example.com"},
                                                  {":path", "/"},
                                                  {":method", "GET"},
                                                  {"te", "trailers, deflate"}},
                                                 /*fin=*/true)
                                        .Serialize();

  // Client preface (empty SETTINGS)
  EXPECT_CALL(visitor, OnFrameHeader(0, 0, SETTINGS, 0));
  EXPECT_CALL(visitor, OnSettingsStart());
  EXPECT_CALL(visitor, OnSettingsEnd());

  // Stream 1: TE: trailers should be allowed.
  EXPECT_CALL(visitor, OnFrameHeader(1, _, HEADERS, 5));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(1));
  EXPECT_CALL(visitor, OnHeaderForStream(1, _, _)).Times(5);
  EXPECT_CALL(visitor, OnEndHeadersForStream(1));
  EXPECT_CALL(visitor, OnEndStream(1));

  // Stream 3: TE: <non-trailers> should be rejected.
  EXPECT_CALL(visitor, OnFrameHeader(3, _, HEADERS, 5));
  EXPECT_CALL(visitor, OnBeginHeadersForStream(3));
  EXPECT_CALL(visitor, OnHeaderForStream(3, _, _)).Times(4);
  EXPECT_CALL(
      visitor,
      OnInvalidFrame(3, Http2VisitorInterface::InvalidFrameError::kHttpHeader));

  const int64_t stream_result = adapter->ProcessBytes(stream_frames);
  EXPECT_EQ(stream_frames.size(), static_cast<size_t>(stream_result));

  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x1));
  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x1, 0));
  EXPECT_CALL(visitor, OnBeforeFrameSent(RST_STREAM, 3, _, 0x0));
  EXPECT_CALL(visitor,
              OnFrameSent(RST_STREAM, 3, _, 0x0,
                          static_cast<int>(Http2ErrorCode::PROTOCOL_ERROR)));
  EXPECT_CALL(visitor, OnCloseStream(3, Http2ErrorCode::HTTP2_NO_ERROR));

  EXPECT_TRUE(adapter->want_write());
  int result = adapter->Send();
  EXPECT_EQ(0, result);
  EXPECT_THAT(visitor.data(),
              EqualsFrames({SpdyFrameType::SETTINGS, SpdyFrameType::SETTINGS,
                            SpdyFrameType::RST_STREAM}));
}

}  // namespace
}  // namespace test
}  // namespace adapter
}  // namespace http2