Better integration tests

tests/ImageSharp.Tests/Processors/Filters/DitherTest.cs

@@ -14,64 +14,88 @@ namespace ImageSharp.Tests
 
     public class DitherTest : FileTestBase
     {
-        [Fact]
-        public void ImageShouldApplyDitherFilter()
+        public static readonly TheoryData<string, IOrderedDither> Ditherers = new TheoryData<string, IOrderedDither>
+        {
+            { "Ordered", new Ordered() },
+            { "Bayer", new Bayer() }
+        };
+
+        public static readonly TheoryData<string, IErrorDiffuser> ErrorDiffusers = new TheoryData<string, IErrorDiffuser>
+        {
+            { "Atkinson", new Atkinson() },
+            { "Burks", new Burks() },
+            { "FloydSteinberg", new FloydSteinberg() },
+            { "JarvisJudiceNinke", new JarvisJudiceNinke() },
+            { "Sierra2", new Sierra2() },
+            { "Sierra3", new Sierra3() },
+            { "SierraLite", new SierraLite() },
+            { "Stucki", new Stucki() },
+        };
+
+        [Theory]
+        [MemberData(nameof(Ditherers))]
+        public void ImageShouldApplyDitherFilter(string name, IOrderedDither ditherer)
         {
             string path = this.CreateOutputDirectory("Dither", "Dither");
 
             foreach (TestFile file in Files)
             {
+                string filename = file.GetFileName(name);
                 using (Image image = file.CreateImage())
-                using (FileStream output = File.OpenWrite($"{path}/{file.FileName}"))
+                using (FileStream output = File.OpenWrite($"{path}/{filename}"))
                 {
-                    image.Dither(new Bayer()).Save(output);
+                    image.Dither(ditherer).Save(output);
                 }
             }
         }
 
-        [Fact]
-        public void ImageShouldApplyDitherFilterInBox()
+        [Theory]
+        [MemberData(nameof(Ditherers))]
+        public void ImageShouldApplyDitherFilterInBox(string name, IOrderedDither ditherer)
         {
             string path = this.CreateOutputDirectory("Dither", "Dither");
 
             foreach (TestFile file in Files)
             {
-                string filename = file.GetFileName("-InBox");
+                string filename = file.GetFileName($"{name}-InBox");
                 using (Image image = file.CreateImage())
                 using (FileStream output = File.OpenWrite($"{path}/{filename}"))
                 {
-                    image.Dither(new Bayer(), new Rectangle(10, 10, image.Width / 2, image.Height / 2)).Save(output);
+                    image.Dither(ditherer, new Rectangle(10, 10, image.Width / 2, image.Height / 2)).Save(output);
                 }
             }
         }
 
-        [Fact]
-        public void ImageShouldApplyDiffusionFilter()
+        [Theory]
+        [MemberData(nameof(ErrorDiffusers))]
+        public void ImageShouldApplyDiffusionFilter(string name, IErrorDiffuser diffuser)
         {
             string path = this.CreateOutputDirectory("Dither", "Diffusion");
 
             foreach (TestFile file in Files)
             {
+                string filename = file.GetFileName(name);
                 using (Image image = file.CreateImage())
-                using (FileStream output = File.OpenWrite($"{path}/{file.FileName}"))
+                using (FileStream output = File.OpenWrite($"{path}/{filename}"))
                 {
-                    image.Dither(new SierraLite(), .5F).Save(output);
+                    image.Dither(diffuser, .5F).Save(output);
                 }
             }
         }
 
-        [Fact]
-        public void ImageShouldApplyDiffusionFilterInBox()
+        [Theory]
+        [MemberData(nameof(ErrorDiffusers))]
+        public void ImageShouldApplyDiffusionFilterInBox(string name, IErrorDiffuser diffuser)
         {
             string path = this.CreateOutputDirectory("Dither", "Diffusion");
 
             foreach (TestFile file in Files)
             {
-                string filename = file.GetFileName("-InBox");
+                string filename = file.GetFileName($"{name}-InBox");
                 using (Image image = file.CreateImage())
                 using (FileStream output = File.OpenWrite($"{path}/{filename}"))
                 {
-                    image.Dither(new SierraLite(), .5F, new Rectangle(10, 10, image.Width / 2, image.Height / 2)).Save(output);
+                    image.Dither(diffuser, .5F, new Rectangle(10, 10, image.Width / 2, image.Height / 2)).Save(output);
                 }
             }
         }