formats/gif/block_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/gif/block.h"

#include <cstdint>
#include <string>
#include <vector>

#include "absl/status/status_matchers.h"
#include "gmock/gmock.h"
#include "gtest/gtest.h"
#include "riegeli/bytes/string_writer.h"

namespace credentio {
namespace {

TEST(BlockTest, Write10BytePayload) {
  std::string manifest_store = "0123456789";

  std::vector<uint8_t> expected_output = {
      0x21, 0xFF, 0x0B, 'C', '2', 'P', 'A', '_', 'G', 'I', 'F', 0x01, 0x00,
      0x00, 0x0a, '0',  '1', '2', '3', '4', '5', '6', '7', '8', '9',  0x00,
  };
  std::string expected(expected_output.begin(), expected_output.end());

  std::string output_s;
  riegeli::StringWriter<> output(&output_s);
  ABSL_ASSERT_OK(WriteGifC2paBlock(manifest_store, output));
  ASSERT_TRUE(output.Close());

  EXPECT_EQ(output_s, expected);
  EXPECT_EQ(output_s.size(), 26);
}

TEST(BlockTest, Write300BytePayload) {
  // Manifest store is 300 bytes long.
  std::string manifest_store(300, 'a');

  // Construct the expected output.
  std::vector<uint8_t> expected_output = {
      0x21, 0xFF, 0x0B, 'C',  '2',  'P',  'A',  '_',
      'G',  'I',  'F',  0x01, 0x00, 0x00, 0xFF,
  };
  expected_output.reserve(expected_output.size() + 302);
  for (uint32_t i = 0; i < 255; ++i) {
    expected_output.push_back('a');
  }
  expected_output.push_back(45);
  for (uint32_t i = 0; i < 45; ++i) {
    expected_output.push_back('a');
  }
  expected_output.push_back(0x00);
  std::string expected(expected_output.begin(), expected_output.end());

  std::string output_s;
  riegeli::StringWriter<> output(&output_s);
  ABSL_ASSERT_OK(WriteGifC2paBlock(manifest_store, output));
  ASSERT_TRUE(output.Close());

  EXPECT_EQ(output_s, expected);
  EXPECT_EQ(output_s.size(), 317);
}

TEST(BlockTest, CalculateSizeOneSubBlock) {
  EXPECT_EQ(CalculateTotalGifC2paBlockSize(10), 26);
}

TEST(BlockTest, CalculateSizeMultipleSubBlocks) {
  EXPECT_EQ(CalculateTotalGifC2paBlockSize(1000), 1019);
}

}  // namespace
}  // namespace credentio