// Copyright 2013 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "third_party/blink/public/common/page_state/page_state_serialization.h"

#include <stddef.h>

#include <cmath>

#include "base/base64.h"
#include "base/containers/span.h"
#include "base/files/file_util.h"
#include "base/path_service.h"
#include "base/pickle.h"
#include "base/strings/string_util.h"
#include "base/strings/stringprintf.h"
#include "base/strings/utf_string_conversions.h"
#include "base/test/metrics/histogram_tester.h"
#include "build/build_config.h"
#include "testing/gtest/include/gtest/gtest.h"
#include "third_party/blink/public/common/loader/http_body_element_type.h"

namespace blink {
namespace {

base::FilePath GetFilePath() {
  base::FilePath path;
  base::PathService::Get(base::DIR_SRC_TEST_DATA_ROOT, &path);
  return base::MakeAbsoluteFilePath(path.Append(
      FILE_PATH_LITERAL("third_party/blink/common/page_state/test_data")));
}

//-----------------------------------------------------------------------------

template <typename T>
void ExpectEquality(const T& expected, const T& actual) {
  EXPECT_EQ(expected, actual);
}

template <typename T>
void ExpectEquality(const std::vector<T>& expected,
                    const std::vector<T>& actual) {
  EXPECT_EQ(expected.size(), actual.size());
  for (size_t i = 0; i < std::min(expected.size(), actual.size()); ++i)
    ExpectEquality(expected[i], actual[i]);
}

template <>
void ExpectEquality(const network::DataElement& expected,
                    const network::DataElement& actual) {
  ASSERT_EQ(expected.type(), actual.type());
  if (expected.type() == network::DataElement::Tag::kBytes) {
    EXPECT_EQ(expected.As<network::DataElementBytes>().bytes(),
              actual.As<network::DataElementBytes>().bytes());
    return;
  }
  if (expected.type() != network::DataElement::Tag::kFile) {
    ADD_FAILURE() << "Impossible to check equality.";
    return;
  }

  const auto& expected_file = expected.As<network::DataElementFile>();
  const auto& actual_file = actual.As<network::DataElementFile>();
  EXPECT_EQ(expected_file.path(), actual_file.path());
  EXPECT_EQ(expected_file.offset(), actual_file.offset());
  EXPECT_EQ(expected_file.length(), actual_file.length());
  EXPECT_EQ(expected_file.expected_modification_time(),
            actual_file.expected_modification_time());
}

template <>
void ExpectEquality(const ExplodedHttpBody& expected,
                    const ExplodedHttpBody& actual) {
  EXPECT_EQ(expected.http_content_type, actual.http_content_type);
  EXPECT_EQ(expected.contains_passwords, actual.contains_passwords);
  if (!expected.request_body || !actual.request_body) {
    EXPECT_EQ(nullptr, expected.request_body);
    EXPECT_EQ(nullptr, actual.request_body);
  } else {
    EXPECT_EQ(expected.request_body->identifier(),
              actual.request_body->identifier());
    ExpectEquality(*expected.request_body->elements(),
                   *actual.request_body->elements());
  }
}

template <>
void ExpectEquality(const ExplodedFrameState& expected,
                    const ExplodedFrameState& actual) {
  EXPECT_EQ(expected.url_string, actual.url_string);
  EXPECT_EQ(expected.referrer, actual.referrer);
  EXPECT_EQ(expected.referrer_policy, actual.referrer_policy);
  EXPECT_EQ(expected.initiator_origin, actual.initiator_origin);
  EXPECT_EQ(expected.initiator_base_url_string,
            actual.initiator_base_url_string);
  EXPECT_EQ(expected.target, actual.target);
  EXPECT_EQ(expected.state_object, actual.state_object);
  ExpectEquality(expected.document_state, actual.document_state);
  EXPECT_EQ(expected.scroll_restoration_type, actual.scroll_restoration_type);
  EXPECT_EQ(expected.visual_viewport_scroll_offset,
            actual.visual_viewport_scroll_offset);
  EXPECT_EQ(expected.scroll_offset, actual.scroll_offset);
  EXPECT_EQ(expected.item_sequence_number, actual.item_sequence_number);
  EXPECT_EQ(expected.document_sequence_number, actual.document_sequence_number);
  EXPECT_EQ(expected.page_scale_factor, actual.page_scale_factor);
  EXPECT_EQ(expected.scroll_anchor_selector, actual.scroll_anchor_selector);
  EXPECT_EQ(expected.scroll_anchor_offset, actual.scroll_anchor_offset);
  EXPECT_EQ(expected.scroll_anchor_simhash, actual.scroll_anchor_simhash);
  EXPECT_EQ(expected.navigation_api_key, actual.navigation_api_key);
  EXPECT_EQ(expected.navigation_api_id, actual.navigation_api_id);
  EXPECT_EQ(expected.navigation_api_state, actual.navigation_api_state);
  EXPECT_EQ(expected.protect_url_in_navigation_api,
            actual.protect_url_in_navigation_api);
  ExpectEquality(expected.http_body, actual.http_body);
  ExpectEquality(expected.children, actual.children);
}

void ExpectEquality(const ExplodedPageState& expected,
                    const ExplodedPageState& actual) {
  ExpectEquality(expected.referenced_files, actual.referenced_files);
  ExpectEquality(expected.top, actual.top);
}

//-----------------------------------------------------------------------------

class PageStateSerializationTest : public testing::Test {
 public:
  void PopulateFrameState(ExplodedFrameState* frame_state) {
    // Invent some data for the various fields.
    frame_state->url_string = u"http://dev.chromium.org/";
    frame_state->referrer = u"https://www.google.com/search?q=dev.chromium.org";
    frame_state->referrer_policy = network::mojom::ReferrerPolicy::kAlways;
    frame_state->target = u"foo";
    frame_state->state_object = std::nullopt;
    frame_state->document_state.push_back(u"1");
    frame_state->document_state.push_back(u"q");
    frame_state->document_state.push_back(u"text");
    frame_state->document_state.push_back(u"dev.chromium.org");
    frame_state->scroll_restoration_type =
        mojom::ScrollRestorationType::kManual;
    frame_state->visual_viewport_scroll_offset = gfx::PointF(10, 15);
    frame_state->scroll_offset = gfx::Point(0, 100);
    frame_state->item_sequence_number = 1;
    frame_state->document_sequence_number = 2;
    frame_state->page_scale_factor = 2.0;
    frame_state->scroll_anchor_selector = u"#selector";
    frame_state->scroll_anchor_offset = gfx::PointF(2.5, 3.5);
    frame_state->scroll_anchor_simhash = 12345;
    frame_state->initiator_origin =
        url::Origin::Create(GURL("https://initiator.example.com"));
    frame_state->navigation_api_key = u"abcd";
    frame_state->navigation_api_id = u"wxyz";
    frame_state->navigation_api_state = std::nullopt;
    frame_state->protect_url_in_navigation_api = false;
    frame_state->initiator_base_url_string =
        base::UTF8ToUTF16(frame_state->initiator_origin->GetURL().spec());
  }

  void PopulateHttpBody(
      ExplodedHttpBody* http_body,
      std::vector<std::optional<std::u16string>>* referenced_files) {
    http_body->request_body = new network::ResourceRequestBody();
    http_body->request_body->set_identifier(12345);
    http_body->contains_passwords = false;
    http_body->http_content_type = u"text/foo";

    std::string test_body("foo");
    http_body->request_body->AppendCopyOfBytes(base::as_byte_span(test_body));

    base::FilePath path(FILE_PATH_LITERAL("file.txt"));
    http_body->request_body->AppendFileRange(
        base::FilePath(path), 100, 1024,
        base::Time::FromSecondsSinceUnixEpoch(9999.0));

    referenced_files->emplace_back(path.AsUTF16Unsafe());
  }

  void PopulateFrameStateForBackwardsCompatTest(ExplodedFrameState* frame_state,
                                                bool is_child,
                                                int version) {
    if (version < 28) {
      // Older versions didn't cover `initiator_origin` -  we expect that
      // deserialization will set it to the default, null value.
      frame_state->initiator_origin = std::nullopt;
    } else if (version < 32) {
      // Here we only give the parent an initiator origin value, and not the
      // child. This is required to match the existing baseline files for
      // versions 28 through 31 inclusive (see https://crbug.com/1405812).
      if (!is_child) {
        frame_state->initiator_origin =
            url::Origin::Create(GURL("https://initiator.example.com"));
      }
    } else {
      // As of version 32, all frames can have an initiator origin.
      frame_state->initiator_origin =
          url::Origin::Create(GURL("https://initiator.example.com"));
    }

    // Some of the test values below are the same as the default value that
    // would be deserialized when reading old versions.  This is undesirable,
    // because it means that the tests do not fully test that a non-default
    // value is correctly deserialized.  Unfortunately this is tricky to change,
    // because these default/old test values are baked into serialized_XX.dat
    // test files (which we should be wary of modifying, since they are supposed
    // to represent set-in-stone old serialization format).
    //
    // When introducing new fields, please test a non-default value, starting
    // with the |version| where the new field is being introduced (set the
    // |version|-dependent test value above - next to and similarly to how
    // |initiator_origin| is handled).
    frame_state->url_string = u"http://chromium.org/";
    frame_state->referrer = u"http://google.com/";
    frame_state->referrer_policy = network::mojom::ReferrerPolicy::kDefault;
    if (!is_child)
      frame_state->target = u"target";
    frame_state->scroll_restoration_type = mojom::ScrollRestorationType::kAuto;
    frame_state->visual_viewport_scroll_offset = gfx::PointF(-1, -1);
    frame_state->scroll_offset = gfx::Point(42, -42);
    frame_state->item_sequence_number = 123;
    frame_state->document_sequence_number = 456;
    frame_state->page_scale_factor = 2.0f;

    frame_state->document_state.push_back(
        u"\n\r?% WebKit serialized form state version 8 \n\r=&");
    frame_state->document_state.push_back(u"form key");
    frame_state->document_state.push_back(u"1");
    frame_state->document_state.push_back(u"foo");
    frame_state->document_state.push_back(u"file");
    frame_state->document_state.push_back(u"2");
    frame_state->document_state.push_back(u"file.txt");
    frame_state->document_state.push_back(u"displayName");

    if (version >= 29) {
      frame_state->navigation_api_key = u"abcdef";
      frame_state->navigation_api_id = u"uvwxyz";
    }
    if (version >= 30)
      frame_state->navigation_api_state = u"js_serialized_state";

    if (version >= 31)
      frame_state->protect_url_in_navigation_api = true;

    if (version >= 33) {
      frame_state->initiator_base_url_string =
          base::UTF8ToUTF16(GURL("https://initiator.example.com").spec());
    }

    if (!is_child) {
      frame_state->http_body.http_content_type = u"foo/bar";
      frame_state->http_body.request_body = new network::ResourceRequestBody();
      frame_state->http_body.request_body->set_identifier(789);

      std::string test_body("first data block");
      frame_state->http_body.request_body->AppendCopyOfBytes(
          base::as_byte_span(test_body));

      frame_state->http_body.request_body->AppendFileRange(
          base::FilePath(FILE_PATH_LITERAL("file.txt")), 0,
          std::numeric_limits<uint64_t>::max(),
          base::Time::FromSecondsSinceUnixEpoch(0.0));

      std::string test_body2("data the second");
      frame_state->http_body.request_body->AppendCopyOfBytes(
          base::as_byte_span(test_body2));

      ExplodedFrameState child_state;
      PopulateFrameStateForBackwardsCompatTest(&child_state, true, version);
      frame_state->children.push_back(child_state);
    }
  }

  void PopulatePageStateForBackwardsCompatTest(ExplodedPageState* page_state,
                                               int version) {
    page_state->referenced_files.push_back(u"file.txt");
    PopulateFrameStateForBackwardsCompatTest(&page_state->top, false, version);
  }

  int GetCurrentVersion() {
    // Because the kCurrentVersion is an internal value not accessible to this
    // test, find it by pulling it out of a newly generated PageState.
    std::string encoded;
    ExplodedPageState page_state;
    EncodePageState(page_state, &encoded);
    return DecodePageStateForTesting(encoded, &page_state);
  }

  void ReadBackwardsCompatPageState(const std::string& suffix,
                                    int version,
                                    ExplodedPageState* page_state) {
    base::FilePath path = GetFilePath();
    path = path.AppendASCII(
        base::StringPrintf("serialized_%s.dat", suffix.c_str()));

    std::string file_contents;
    if (!base::ReadFileToString(path, &file_contents)) {
      ADD_FAILURE() << "File not found: " << path.value();
      return;
    }

    std::string trimmed_file_contents;
    EXPECT_TRUE(
        base::RemoveChars(file_contents, "\r\n", &trimmed_file_contents));

    std::string saved_encoded_state;
    // PageState is encoded twice; once via EncodePageState, and again
    // via Base64Decode, so we need to Base64Decode to get the original
    // encoded PageState.
    EXPECT_TRUE(
        base::Base64Decode(trimmed_file_contents, &saved_encoded_state));

#if BUILDFLAG(IS_ANDROID)
    // Because version 11 of the file format unfortunately bakes in the device
    // scale factor on Android, perform this test by assuming a preset device
    // scale factor, ignoring the device scale factor of the current device.
    const float kPresetDeviceScaleFactor = 2.0f;
    EXPECT_TRUE(DecodePageStateWithDeviceScaleFactorForTesting(
        saved_encoded_state, kPresetDeviceScaleFactor, page_state));
#else
    EXPECT_EQ(version,
              DecodePageStateForTesting(saved_encoded_state, page_state));
#endif
  }

  void TestBackwardsCompat(int version) {
    std::string suffix = base::StringPrintf("v%d", version);

#if BUILDFLAG(IS_ANDROID)
    // Unfortunately, the format of version 11 is different on Android, so we
    // need to use a special reference file.
    if (version == 11) {
      suffix = std::string("v11_android");
    }
#endif

    ExplodedPageState decoded_state;
    ExplodedPageState expected_state;
    PopulatePageStateForBackwardsCompatTest(&expected_state, version);

    base::HistogramTester histogram_tester;
    ReadBackwardsCompatPageState(suffix, version, &decoded_state);
    if (version < GetCurrentVersion()) {
      // Older versions should generate a histogram value when decoded.
      histogram_tester.ExpectBucketCount("SessionRestore.PageStateOldVersions",
                                         version, 1);
    }

    ExpectEquality(expected_state, decoded_state);
  }
};

TEST_F(PageStateSerializationTest, InitiatorOriginAssign) {
  ExplodedFrameState a, b;
  a.initiator_origin =
      url::Origin::Create(GURL("https://initiator.example.com"));
  b = a;
  ExpectEquality(a, b);

  ExplodedFrameState c(a);
  ExpectEquality(a, c);
}

TEST_F(PageStateSerializationTest, BasicEmpty) {
  ExplodedPageState input;

  std::string encoded;
  EncodePageState(input, &encoded);

  ExplodedPageState output;
  EXPECT_TRUE(DecodePageState(encoded, &output));

  ExpectEquality(input, output);
}

TEST_F(PageStateSerializationTest, BasicFrame) {
  ExplodedPageState input;
  PopulateFrameState(&input.top);

  std::string encoded;
  EncodePageState(input, &encoded);

  ExplodedPageState output;
  EXPECT_TRUE(DecodePageState(encoded, &output));

  ExpectEquality(input, output);
}

TEST_F(PageStateSerializationTest, BasicFramePOST) {
  ExplodedPageState input;
  PopulateFrameState(&input.top);
  PopulateHttpBody(&input.top.http_body, &input.referenced_files);

  std::string encoded;
  EncodePageState(input, &encoded);

  ExplodedPageState output;
  EXPECT_TRUE(DecodePageState(encoded, &output));

  ExpectEquality(input, output);
}

TEST_F(PageStateSerializationTest, BasicFrameSet) {
  ExplodedPageState input;
  PopulateFrameState(&input.top);

  // Add some child frames.
  for (int i = 0; i < 4; ++i) {
    ExplodedFrameState child_state;
    PopulateFrameState(&child_state);
    input.top.children.push_back(child_state);

    // Ensure `child_state` made it into `input` successfully, to catch any
    // cases where ExplodedFrameState::assign may have been missed.
    ExpectEquality(child_state, input.top.children[i]);
  }

  std::string encoded;
  EncodePageState(input, &encoded);

  ExplodedPageState output;
  EXPECT_TRUE(DecodePageState(encoded, &output));

  ExpectEquality(input, output);
}

TEST_F(PageStateSerializationTest, BasicFrameSetPOST) {
  ExplodedPageState input;
  PopulateFrameState(&input.top);

  // Add some child frames.
  for (int i = 0; i < 4; ++i) {
    ExplodedFrameState child_state;
    PopulateFrameState(&child_state);

    // Simulate a form POST on a subframe.
    if (i == 2)
      PopulateHttpBody(&child_state.http_body, &input.referenced_files);

    input.top.children.push_back(child_state);
  }

  std::string encoded;
  EncodePageState(input, &encoded);

  ExplodedPageState output;
  DecodePageState(encoded, &output);

  ExpectEquality(input, output);
}

TEST_F(PageStateSerializationTest, BadMessagesTest1) {
  base::Pickle p;
  // Version 14
  p.WriteInt(14);
  // Empty strings.
  for (int i = 0; i < 6; ++i)
    p.WriteInt(-1);
  // Bad real number.
  p.WriteInt(-1);

  std::string s(p.AsStringView());

  ExplodedPageState output;
  EXPECT_FALSE(DecodePageState(s, &output));
}

TEST_F(PageStateSerializationTest, BadMessagesTest2) {
  double d = 0;
  base::Pickle p;
  // Version 14
  p.WriteInt(14);
  // Empty strings.
  for (int i = 0; i < 6; ++i)
    p.WriteInt(-1);
  // More misc fields.
  p.WriteData(base::byte_span_from_ref(base::allow_nonunique_obj, d));
  p.WriteInt(1);
  p.WriteInt(1);
  p.WriteInt(0);
  p.WriteInt(0);
  p.WriteInt(-1);
  p.WriteInt(0);
  // WebForm
  p.WriteInt(1);
  p.WriteInt(static_cast<int>(HTTPBodyElementType::kTypeData));

  std::string s(p.AsStringView());

  ExplodedPageState output;
  EXPECT_FALSE(DecodePageState(s, &output));
}

// Tests that LegacyEncodePageState, which uses the pre-mojo serialization
// format, produces the exact same blob as it did when the test was written.
// This ensures that the implementation is frozen, which is needed to correctly
// test compatibility and migration.
TEST_F(PageStateSerializationTest, LegacyEncodePageStateFrozen) {
  ExplodedPageState actual_state;
  PopulatePageStateForBackwardsCompatTest(&actual_state, 25);

  std::string actual_encoded_state;
  LegacyEncodePageStateForTesting(actual_state, 25, &actual_encoded_state);

  base::FilePath path = GetFilePath();
  path = path.AppendASCII("serialized_v25.dat");

  std::string file_contents;
  ASSERT_TRUE(base::ReadFileToString(path, &file_contents))
      << "File not found: " << path.value();

  std::string trimmed_file_contents;
  EXPECT_TRUE(base::RemoveChars(file_contents, "\n", &trimmed_file_contents));

  std::string expected_encoded_state;
  EXPECT_TRUE(
      base::Base64Decode(trimmed_file_contents, &expected_encoded_state));

  ExpectEquality(actual_encoded_state, expected_encoded_state);
}

TEST_F(PageStateSerializationTest, ScrollAnchorSelectorLengthLimited) {
  ExplodedPageState input;
  PopulateFrameState(&input.top);

  input.top.scroll_anchor_selector =
      std::u16string(kMaxScrollAnchorSelectorLength + 1, u'a');

  std::string encoded;
  EncodePageState(input, &encoded);

  ExplodedPageState output;
  DecodePageState(encoded, &output);

  // We should drop all the scroll anchor data if the length is over the limit.
  EXPECT_FALSE(output.top.scroll_anchor_selector);
  EXPECT_EQ(output.top.scroll_anchor_offset, gfx::PointF());
  EXPECT_EQ(output.top.scroll_anchor_simhash, 0ul);
}

// Change to #if 1 to enable this code. Run this test to generate data, based on
// the current serialization format, for the BackwardsCompat_vXX tests. This
// will generate an expected.dat in the temp directory, which should be moved
// //third_party/blink/common/page_state/test_data/serialized_vXX.dat. A
// corresponding test case for that version should also then be added below. You
// need to add such a test for any addition/change to the schema of serialized
// page state. If you're adding a field whose type is defined externally of
// page_state.mojom, add an backwards compat test for that field specifically
// by dumping a state object with only that field populated. See, e.g.,
// BackwardsCompat_UrlString as an example.
//
// IMPORTANT: this code dumps the serialization as the *current* version, so if
// generating a backwards compat test for v23, the tree must be synced to a
// revision where page_state_serialization.cc:kCurrentVersion == 23.
#if 0
TEST_F(PageStateSerializationTest, DumpExpectedPageStateForBackwardsCompat) {
  // Populate |state| with test data suitable for testing the current (i.e. the
  // latest) version of serialization.  This is accomplished by asking for test
  // data for version 9999 - a future, hypothetical version number.
  ExplodedPageState state;
  PopulatePageStateForBackwardsCompatTest(&state, 9999);

  std::string encoded;
  EncodePageState(state, &encoded);

  std::string base64 = base::Base64Encode(encoded);

  base::FilePath path;
  base::PathService::Get(base::DIR_TEMP, &path);
  path = path.AppendASCII("expected.dat");

  FILE* fp = base::OpenFile(path, "wb");
  ASSERT_TRUE(fp);

  const size_t kRowSize = 76;
  for (size_t offset = 0; offset < base64.size(); offset += kRowSize) {
    size_t length = std::min(base64.size() - offset, kRowSize);
    std::string segment(&base64[offset], length);
    segment.push_back('\n');
    ASSERT_EQ(1U, fwrite(segment.data(), segment.size(), 1, fp));
  }

  fclose(fp);
}
#endif

#if !BUILDFLAG(IS_ANDROID)
// TODO(darin): Re-enable for Android once this test accounts for systems with
//              a device scale factor not equal to 2.
TEST_F(PageStateSerializationTest, BackwardsCompat_v11) {
  TestBackwardsCompat(11);
}
#endif

TEST_F(PageStateSerializationTest, BackwardsCompat_v12) {
  TestBackwardsCompat(12);
}

TEST_F(PageStateSerializationTest, BackwardsCompat_v13) {
  TestBackwardsCompat(13);
}

TEST_F(PageStateSerializationTest, BackwardsCompat_v14) {
  TestBackwardsCompat(14);
}

TEST_F(PageStateSerializationTest, BackwardsCompat_v15) {
  TestBackwardsCompat(15);
}

TEST_F(PageStateSerializationTest, BackwardsCompat_v16) {
  TestBackwardsCompat(16);
}

TEST_F(PageStateSerializationTest, BackwardsCompat_v18) {
  TestBackwardsCompat(18);
}

TEST_F(PageStateSerializationTest, BackwardsCompat_v20) {
  TestBackwardsCompat(20);
}

TEST_F(PageStateSerializationTest, BackwardsCompat_v21) {
  TestBackwardsCompat(21);
}

TEST_F(PageStateSerializationTest, BackwardsCompat_v22) {
  TestBackwardsCompat(22);
}

TEST_F(PageStateSerializationTest, BackwardsCompat_v23) {
  TestBackwardsCompat(23);
}

TEST_F(PageStateSerializationTest, BackwardsCompat_v24) {
  TestBackwardsCompat(24);
}

TEST_F(PageStateSerializationTest, BackwardsCompat_v25) {
  TestBackwardsCompat(25);
}

TEST_F(PageStateSerializationTest, BackwardsCompat_v26) {
  TestBackwardsCompat(26);
}

TEST_F(PageStateSerializationTest, BackwardsCompat_v27) {
  TestBackwardsCompat(27);
}

TEST_F(PageStateSerializationTest, BackwardsCompat_v28) {
  TestBackwardsCompat(28);
}

TEST_F(PageStateSerializationTest, BackwardsCompat_v29) {
  TestBackwardsCompat(29);
}

TEST_F(PageStateSerializationTest, BackwardsCompat_v30) {
  TestBackwardsCompat(30);
}

TEST_F(PageStateSerializationTest, BackwardsCompat_v31) {
  TestBackwardsCompat(31);
}

TEST_F(PageStateSerializationTest, BackwardsCompat_v32) {
  TestBackwardsCompat(32);
}

TEST_F(PageStateSerializationTest, BackwardsCompat_v33) {
  TestBackwardsCompat(33);
}

// Add your new backwards compat test for future versions *above* this
// comment block; field-specific tests go *below* this comment block.
// Any field additions require a new version and backcompat test; only fields
// with external type definitions require their own dedicated test.
// See DumpExpectedPageStateForBackwardsCompat for more details.
// If any of the below tests fail, you likely made a backwards incompatible
// change to a definition that page_state.mojom relies on. Ideally you should
// find a way to avoid making this change; if that's not possible, contact the
// page state serialization owners to figure out a resolution.

TEST_F(PageStateSerializationTest, BackwardsCompat_ReferencedFiles) {
  ExplodedPageState state;
  state.referenced_files.push_back(u"file.txt");

  ExplodedPageState saved_state;
  ReadBackwardsCompatPageState("referenced_files", 26, &saved_state);
  ExpectEquality(state, saved_state);
}

TEST_F(PageStateSerializationTest, BackwardsCompat_UrlString) {
  ExplodedPageState state;
  state.top.url_string = u"http://chromium.org";

  ExplodedPageState saved_state;
  ReadBackwardsCompatPageState("url_string", 26, &saved_state);
  ExpectEquality(state, saved_state);
}

TEST_F(PageStateSerializationTest, BackwardsCompat_Referrer) {
  ExplodedPageState state;
  state.top.referrer = u"http://www.google.com";

  ExplodedPageState saved_state;
  ReadBackwardsCompatPageState("referrer", 26, &saved_state);
  ExpectEquality(state, saved_state);
}

TEST_F(PageStateSerializationTest, BackwardsCompat_Target) {
  ExplodedPageState state;
  state.top.target = u"http://www.google.com";

  ExplodedPageState saved_state;
  ReadBackwardsCompatPageState("target", 26, &saved_state);
  ExpectEquality(state, saved_state);
}

TEST_F(PageStateSerializationTest, BackwardsCompat_StateObject) {
  ExplodedPageState state;
  state.top.state_object = u"state";

  ExplodedPageState saved_state;
  ReadBackwardsCompatPageState("state_object", 26, &saved_state);
  ExpectEquality(state, saved_state);
}

TEST_F(PageStateSerializationTest, BackwardsCompat_DocumentState) {
  ExplodedPageState state;
  state.top.document_state.push_back(
      u"\n\r?% WebKit serialized form state version 8 \n\r=&");

  ExplodedPageState saved_state;
  ReadBackwardsCompatPageState("document_state", 26, &saved_state);
  ExpectEquality(state, saved_state);
}

TEST_F(PageStateSerializationTest, BackwardsCompat_ScrollRestorationType) {
  ExplodedPageState state;
  state.top.scroll_restoration_type = mojom::ScrollRestorationType::kManual;

  ExplodedPageState saved_state;
  ReadBackwardsCompatPageState("scroll_restoration_type", 26, &saved_state);
  ExpectEquality(state, saved_state);
}

TEST_F(PageStateSerializationTest, BackwardsCompat_VisualViewportScrollOffset) {
  ExplodedPageState state;
  state.top.visual_viewport_scroll_offset = gfx::PointF(42.2, -42.2);

  ExplodedPageState saved_state;
  ReadBackwardsCompatPageState("visual_viewport_scroll_offset", 26,
                               &saved_state);
  ExpectEquality(state, saved_state);
}

TEST_F(PageStateSerializationTest, BackwardsCompat_ScrollOffset) {
  ExplodedPageState state;
  state.top.scroll_offset = gfx::Point(1, -1);

  ExplodedPageState saved_state;
  ReadBackwardsCompatPageState("scroll_offset", 26, &saved_state);
  ExpectEquality(state, saved_state);
}

TEST_F(PageStateSerializationTest, BackwardsCompat_ReferrerPolicy) {
  ExplodedPageState state;
  state.top.referrer_policy = network::mojom::ReferrerPolicy::kAlways;

  ExplodedPageState saved_state;
  ReadBackwardsCompatPageState("referrer_policy", 26, &saved_state);
  ExpectEquality(state, saved_state);
}

TEST_F(PageStateSerializationTest, BackwardsCompat_HttpBody) {
  ExplodedPageState state;
  ExplodedHttpBody& http_body = state.top.http_body;

  http_body.request_body = new network::ResourceRequestBody();
  http_body.request_body->set_identifier(12345);
  http_body.contains_passwords = false;
  http_body.http_content_type = u"text/foo";

  std::string test_body("foo");
  http_body.request_body->AppendCopyOfBytes(base::as_byte_span(test_body));

  base::FilePath path(FILE_PATH_LITERAL("file.txt"));
  http_body.request_body->AppendFileRange(
      base::FilePath(path), 100, 1024,
      base::Time::FromSecondsSinceUnixEpoch(9999.0));

  ExplodedPageState saved_state;
  ReadBackwardsCompatPageState("http_body", 26, &saved_state);
  ExpectEquality(state, saved_state);
}

// Add new backwards compat field-specific tests here.  See comment above for
// where to put backwards compat version tests.

}  // namespace
}  // namespace blink