better BmpEncoderTests

tests/ImageSharp.Tests/Formats/Bmp/BmpEncoderTests.cs

@@ -8,28 +8,59 @@ using Xunit;
 
 namespace SixLabors.ImageSharp.Tests
 {
+    using SixLabors.ImageSharp.Tests.TestUtilities.ImageComparison;
+
+    using Xunit.Abstractions;
+
     public class BmpEncoderTests : FileTestBase
     {
-        public static readonly TheoryData<BmpBitsPerPixel> BitsPerPixel
+        private const PixelTypes PixelTypesToTest = PixelTypes.Rgba32 | PixelTypes.Bgra32 | PixelTypes.Rgb24;
-        = new TheoryData<BmpBitsPerPixel>
+
+        public static readonly TheoryData<BmpBitsPerPixel> BitsPerPixel =
+            new TheoryData<BmpBitsPerPixel>
                 {
                     BmpBitsPerPixel.Pixel24,
                     BmpBitsPerPixel.Pixel32
                 };
 
-        [Theory]
+        public BmpEncoderTests(ITestOutputHelper output)
-        [MemberData(nameof(BitsPerPixel))]
-        public void BitmapCanEncodeDifferentBitRates(BmpBitsPerPixel bitsPerPixel)
         {
-            string path = TestEnvironment.CreateOutputDirectory("Bmp");
+            this.Output = output;
+        }
+
+        private ITestOutputHelper Output { get; }
 
-            foreach (TestFile file in Files)
+        [Theory]
+        [WithTestPatternImages(nameof(BitsPerPixel), 48, 24, PixelTypesToTest)]
+        [WithTestPatternImages(nameof(BitsPerPixel), 47, 8, PixelTypesToTest)]
+        [WithTestPatternImages(nameof(BitsPerPixel), 49, 7, PixelTypesToTest)]
+        [WithSolidFilledImages(nameof(BitsPerPixel), 1, 1, 255, 100, 50, 255, PixelTypesToTest)]
+        [WithTestPatternImages(nameof(BitsPerPixel), 7, 5, PixelTypesToTest)]
+        public void Encode<TPixel>(TestImageProvider<TPixel> provider, BmpBitsPerPixel bitsPerPixel)
+            where TPixel : struct, IPixel<TPixel>
         {
-                string filename = file.GetFileNameWithoutExtension(bitsPerPixel);
+            
-                using (Image<Rgba32> image = file.CreateImage())
+            using (Image<TPixel> image = provider.GetImage())
             {
-                    image.Save($"{path}/{filename}.bmp", new BmpEncoder { BitsPerPixel = bitsPerPixel });
+                // there is no alpha in bmp!
-                }
+                image.Mutate(
+                    c => c.Opacity(1)
+                    );
+                
+                var encoder = new BmpEncoder { BitsPerPixel = bitsPerPixel };
+                string path = provider.Utility.SaveTestOutputFile(image, "bmp", encoder, testOutputDetails:bitsPerPixel);
+
+                this.Output.WriteLine(path);
+
+                IImageDecoder referenceDecoder = TestEnvironment.GetReferenceDecoder(path);
+                string referenceOutputFile = provider.Utility.GetReferenceOutputFileName("bmp", bitsPerPixel, true);
+
+                this.Output.WriteLine(referenceOutputFile);
+
+                //using (var encodedImage = Image.Load<TPixel>(referenceOutputFile, referenceDecoder))
+                //{
+                //    ImageComparer.Exact.CompareImagesOrFrames(image, encodedImage);
+                //}
             }
         }
     }

tests/ImageSharp.Tests/TestUtilities/ImageProviders/TestPatternProvider.cs

@@ -86,9 +86,10 @@ namespace SixLabors.ImageSharp.Tests
                                      NamedColors<TPixel>.HotPink,
                                      NamedColors<TPixel>.Blue
                                  };
-                int p = 0;
+                
                 for (int y = top; y < bottom; y++)
                 {
+                    int p = 0;
                     for (int x = left; x < right; x++)
                     {
                         if (x % stride == 0)