ImageSharp/tests/ImageSharp.Formats.Tiff.Tests/Formats/Tiff/TiffIfd/TiffIfdTests.cs

// <copyright file="TiffIfdTests.cs" company="James Jackson-South">
// Copyright (c) James Jackson-South and contributors.
// Licensed under the Apache License, Version 2.0.
// </copyright>

namespace ImageSharp.Tests
{
    using System.IO;
    using Xunit;

    using ImageSharp.Formats;

    public class TiffIfdTests
    {
        [Fact]
        public void Constructor_SetsProperties()
        {
            var entries = new TiffIfdEntry[10];
            var ifd = new TiffIfd(entries, 1234u);

            Assert.Equal(entries, ifd.Entries);
            Assert.Equal(1234u, ifd.NextIfdOffset);
        }

        [Fact]
        public void GetIfdEntry_ReturnsIfdIfExists()
        {
            var entries = new[]
                    {
                        new TiffIfdEntry(10, TiffType.Short, 20, new byte[4]),
                        new TiffIfdEntry(20, TiffType.Short, 20, new byte[4]),
                        new TiffIfdEntry(30, TiffType.Short, 20, new byte[4]),
                        new TiffIfdEntry(40, TiffType.Short, 20, new byte[4])
                    };
            var ifd = new TiffIfd(entries, 1234u);

            TiffIfdEntry? entry = ifd.GetIfdEntry(30);

            Assert.Equal(true, entry.HasValue);
            Assert.Equal(30, entry.Value.Tag);
        }

        [Fact]
        public void GetIfdEntry_ReturnsNullOtherwise()
        {
            var entries = new[]
                    {
                        new TiffIfdEntry(10, TiffType.Short, 20, new byte[4]),
                        new TiffIfdEntry(20, TiffType.Short, 20, new byte[4]),
                        new TiffIfdEntry(30, TiffType.Short, 20, new byte[4]),
                        new TiffIfdEntry(40, TiffType.Short, 20, new byte[4])
                    };
            var ifd = new TiffIfd(entries, 1234u);

            TiffIfdEntry? entry = ifd.GetIfdEntry(25);

            Assert.Equal(false, entry.HasValue);
        }

        [Fact]
        public void TryGetIfdEntry_ReturnsIfdIfExists()
        {
            var entries = new[]
                    {
                        new TiffIfdEntry(10, TiffType.Short, 20, new byte[4]),
                        new TiffIfdEntry(20, TiffType.Short, 20, new byte[4]),
                        new TiffIfdEntry(30, TiffType.Short, 20, new byte[4]),
                        new TiffIfdEntry(40, TiffType.Short, 20, new byte[4])
                    };
            var ifd = new TiffIfd(entries, 1234u);

            bool success = ifd.TryGetIfdEntry(30, out var entry);

            Assert.Equal(true, success);
            Assert.Equal(30, entry.Tag);
        }

        [Fact]
        public void TryGetIfdEntry_ReturnsFalseOtherwise()
        {
            var entries = new[]
                    {
                        new TiffIfdEntry(10, TiffType.Short, 20, new byte[4]),
                        new TiffIfdEntry(20, TiffType.Short, 20, new byte[4]),
                        new TiffIfdEntry(30, TiffType.Short, 20, new byte[4]),
                        new TiffIfdEntry(40, TiffType.Short, 20, new byte[4])
                    };
            var ifd = new TiffIfd(entries, 1234u);

            bool success = ifd.TryGetIfdEntry(25, out var entry);

            Assert.Equal(false, success);
            Assert.Equal(0, entry.Tag);
        }
    }
}