PixiEditor/PixiEditorTests/ModelsTests/ToolsTests/BrightnessToolTests.cs

using System.Windows.Media;
using PixiEditor.Models.Layers;
using PixiEditor.Models.Position;
using PixiEditor.Models.Tools.Tools;
using Xunit;

namespace PixiEditorTests.ModelsTests.ToolsTests
{
    [Collection("Application collection")]
    public class BrightnessToolTests
    {
        [StaTheory]
        [InlineData(5, 12, 12, 12)]
        [InlineData(-5, 242, 242, 242)]

        // If correction factor is negative, testing color will be white, otherwise black
        public void TestThatBrightnessToolChangesPixelBrightness(float correctionFactor, byte expectedR, byte expectedG, byte expectedB)
        {
            Color expectedColor = Color.FromRgb(expectedR, expectedG, expectedB);

            BrightnessTool tool = new BrightnessTool();

            Layer layer = new Layer("test", 1, 1);
            layer.SetPixel(new Coordinates(0, 0), correctionFactor < 0 ? Colors.White : Colors.Black);

            PixiEditor.Models.DataHolders.BitmapPixelChanges changes = tool.ChangeBrightness(layer, new Coordinates(0, 0), 1, correctionFactor);
            layer.SetPixels(changes);

            Assert.Equal(expectedColor, layer.GetPixel(0, 0));
        }
    }
}