formats/jpeg/box_header_test.cc

// Copyright 2026 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//    https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//

#include "formats/jpeg/box_header.h"

#include <cstdint>
#include <string>

#include "absl/status/status.h"
#include "absl/status/status_matchers.h"
#include "absl/strings/str_format.h"
#include "gmock/gmock.h"
#include "gtest/gtest.h"
#include "riegeli/bytes/string_reader.h"

namespace credentio {
namespace {

using ::absl_testing::StatusIs;
using ::testing::Range;
using ::testing::TestParamInfo;

using BoxHeaderTest = testing::TestWithParam<uint32_t>;

INSTANTIATE_TEST_SUITE_P(MarkerTests, BoxHeaderTest,
                         Range(static_cast<uint32_t>(0x0000feff),
                               static_cast<uint32_t>(0x00010000)),
                         [](const TestParamInfo<uint32_t>& info) {
                           return absl::StrFormat(
                               "%04x", static_cast<uint16_t>(info.param));
                         });

TEST_P(BoxHeaderTest, ConsumeJpegBoxHeaderTest) {
  std::string data("\0\0\0\4\1\1", 6);
  data[0] = static_cast<uint8_t>((GetParam() & 0x0000ff00) >> 8);
  data[1] = static_cast<uint8_t>((GetParam() & 0x000000ff));

  riegeli::StringReader<> input(data);

  if (GetParam() < 0xff00 || GetParam() == 0xffff) {
    // Invalid marker.
    EXPECT_THAT(ConsumeJpegBoxHeader(input),
                StatusIs(absl::StatusCode::kInvalidArgument));
    return;
  }

  auto header_or = ConsumeJpegBoxHeader(input);
  ABSL_ASSERT_OK(header_or);

  JpegBoxHeader header = *header_or;
  EXPECT_EQ(header.offset, 0);
  EXPECT_EQ(header.type, GetParam());
  if (GetParam() == 0xff01 || (GetParam() >= 0xffd0 && GetParam() <= 0xffd9)) {
    EXPECT_EQ(header.size, 2);
  } else {
    EXPECT_EQ(header.size, 6);  // Length + 2 for the marker
  }
}

TEST(BoxHeaderTest, ConsumeJpegBoxHeaderEmptyInput) {
  std::string data("");
  riegeli::StringReader<> input(data);
  EXPECT_THAT(ConsumeJpegBoxHeader(input),
              StatusIs(absl::StatusCode::kDataLoss,
                       ::testing::HasSubstr("Failed to read type")));
}

TEST(BoxHeaderTest, ConsumeJpegBoxHeaderShortInputForSize) {
  std::string data("\xff\xe1\x00", 3);
  riegeli::StringReader<> input(data);
  EXPECT_THAT(ConsumeJpegBoxHeader(input),
              StatusIs(absl::StatusCode::kDataLoss,
                       ::testing::HasSubstr("Failed to read size")));
}

TEST_P(BoxHeaderTest, ConvertMarkerToLabelTest) {
  uint16_t marker = static_cast<uint16_t>(GetParam() & 0x0000ffff);
  JpegBoxHeader header = {.type = marker};

  switch (marker) {
    case 0xfeff:
      EXPECT_EQ(header.label(), "feff");
      return;
    case 0xff01:
      EXPECT_EQ(header.label(), "TEM");
      return;
    case 0xffc4:
      EXPECT_EQ(header.label(), "DHT");
      return;
    case 0xffc8:
      EXPECT_EQ(header.label(), "JPG");
      return;
    case 0xffcc:
      EXPECT_EQ(header.label(), "DAC");
      return;
    case 0xffd8:
      EXPECT_EQ(header.label(), "SOI");
      return;
    case 0xffd9:
      EXPECT_EQ(header.label(), "EOI");
      return;
    case 0xffda:
      EXPECT_EQ(header.label(), "SOS");
      return;
    case 0xffdb:
      EXPECT_EQ(header.label(), "DQT");
      return;
    case 0xffdc:
      EXPECT_EQ(header.label(), "DNL");
      return;
    case 0xffdd:
      EXPECT_EQ(header.label(), "DRI");
      return;
    case 0xffde:
      EXPECT_EQ(header.label(), "DHP");
      return;
    case 0xffdf:
      EXPECT_EQ(header.label(), "EXP");
      return;
    case 0xfffe:
      EXPECT_EQ(header.label(), "COM");
      return;
    case 0xffff:
      EXPECT_EQ(header.label(), "ffff");
      return;
  }

  if ((marker & 0x00f0) == 0x00c0) {
    EXPECT_EQ(header.label(), absl::StrFormat("SOF%d", (marker & 0x000f)));
    return;
  }
  if (marker >= 0xffd0 && marker <= 0xffd7) {
    EXPECT_EQ(header.label(), absl::StrFormat("RST%d", (marker & 0x000f)));
    return;
  }
  if ((marker & 0x00f0) == 0x00e0) {
    EXPECT_EQ(header.label(), absl::StrFormat("APP%d", (marker & 0x000f)));
    return;
  }
  if (marker >= 0xfff0 && marker <= 0xfffd) {
    EXPECT_EQ(header.label(), absl::StrFormat("JPG%d", (marker & 0x000f)));
    return;
  }
  EXPECT_EQ(header.label(), "RES");
}

TEST(BoxHeaderTest, PrintToJpegBoxHeader) {
  JpegBoxHeader header = {.type = 0xffe1, .offset = 10, .size = 20};
  EXPECT_EQ(testing::PrintToString(header),
            "{type: 65505, offset: 10, size: 20, label: \"APP1\"}");
}

}  // namespace
}  // namespace credentio