ImageSharp/tests/ImageSharp.Tests/Formats/Tiff/Compression/DeflateTiffCompressionTests.cs

// Copyright (c) Six Labors.
// Licensed under the Apache License, Version 2.0.

using System.IO;
using SixLabors.ImageSharp.Compression.Zlib;
using SixLabors.ImageSharp.Formats.Tiff.Compression.Decompressors;
using SixLabors.ImageSharp.Formats.Tiff.Constants;
using SixLabors.ImageSharp.IO;

using Xunit;

namespace SixLabors.ImageSharp.Tests.Formats.Tiff.Compression
{
    [Trait("Format", "Tiff")]
    public class DeflateTiffCompressionTests
    {
        [Theory]
        [InlineData(new byte[] { })]
        [InlineData(new byte[] { 42 })] // One byte
        [InlineData(new byte[] { 42, 16, 128, 53, 96, 218, 7, 64, 3, 4, 97 })] // Random bytes
        [InlineData(new byte[] { 1, 2, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 3, 4 })] // Repeated bytes
        [InlineData(new byte[] { 1, 2, 42, 53, 42, 53, 42, 53, 42, 53, 42, 53, 3, 4 })] // Repeated sequence
        public void Compress_Decompress_Roundtrip_Works(byte[] data)
        {
            using (BufferedReadStream stream = CreateCompressedStream(data))
            {
                var buffer = new byte[data.Length];

                using var decompressor = new DeflateTiffCompression(Configuration.Default.MemoryAllocator, 10, 8, TiffPredictor.None);

                decompressor.Decompress(stream, 0, (uint)stream.Length, buffer);

                Assert.Equal(data, buffer);
            }
        }

        private static BufferedReadStream CreateCompressedStream(byte[] data)
        {
            Stream compressedStream = new MemoryStream();

            using (Stream uncompressedStream = new MemoryStream(data),
                          deflateStream = new ZlibDeflateStream(Configuration.Default.MemoryAllocator, compressedStream, DeflateCompressionLevel.Level6))
            {
                uncompressedStream.CopyTo(deflateStream);
            }

            compressedStream.Seek(0, SeekOrigin.Begin);
            return new BufferedReadStream(Configuration.Default, compressedStream);
        }
    }
}