Add tests for executing only one transform

tests/ImageSharp.Tests/Formats/WebP/Vp8EncodingTests.cs

@@ -11,7 +11,39 @@ namespace SixLabors.ImageSharp.Tests.Formats.WebP
     [Trait("Format", "Webp")]
     public class Vp8EncodingTests
     {
-        private static void RunInverseTransformTest()
+        private static void RunOneInverseTransformTest()
+        {
+            // arrange
+            byte[] reference =
+            {
+                128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 129, 129, 129, 129,
+                129, 129, 129, 129, 129, 129, 129, 129, 129, 129, 129, 129, 128, 128, 128, 128, 128, 128, 128, 128,
+                128, 128, 128, 128, 128, 128, 128, 128, 129, 129, 129, 129, 129, 129, 129, 129, 129, 129, 129, 129,
+                129, 129, 129, 129, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128,
+                129, 129, 129, 129, 129, 129, 129, 129, 129, 129, 129, 129, 129, 129, 129, 129, 128, 128, 128, 128,
+                128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 129, 129, 129, 129, 129, 129, 129, 129,
+                129, 129, 129, 129, 129, 129, 129, 129
+            };
+            short[] input = { 1, 216, -48, 0, 96, -24, -48, 24, 0, -24, 24, 0, 0, 0, 0, 0, 38, -240, -72, -24, 0, -24, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
+            byte[] dst = new byte[128];
+            byte[] expected =
+            {
+                161, 160, 149, 105, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+                0, 160, 160, 133, 85, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+                0, 0, 156, 147, 109, 76, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+                0, 0, 0, 152, 128, 87, 83, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+                0, 0, 0, 0
+            };
+            int[] scratch = new int[16];
+
+            // act
+            Vp8Encoding.ITransform(reference, input, dst, false, scratch);
+
+            // assert
+            Assert.True(dst.SequenceEqual(expected));
+        }
+
+        private static void RunTwoInverseTransformTest()
         {
             // arrange
             byte[] reference =
@@ -44,14 +76,23 @@ namespace SixLabors.ImageSharp.Tests.Formats.WebP
         }
 
         [Fact]
-        public void InverseTransform_Works() => RunInverseTransformTest();
+        public void OneInverseTransform_Works() => RunOneInverseTransformTest();
+
+        [Fact]
+        public void TwoInverseTransform_Works() => RunTwoInverseTransformTest();
 
 #if SUPPORTS_RUNTIME_INTRINSICS
         [Fact]
-        public void InverseTransform_WithHardwareIntrinsics_Works() => FeatureTestRunner.RunWithHwIntrinsicsFeature(RunInverseTransformTest, HwIntrinsics.AllowAll);
+        public void OneInverseTransform_WithHardwareIntrinsics_Works() => FeatureTestRunner.RunWithHwIntrinsicsFeature(RunOneInverseTransformTest, HwIntrinsics.AllowAll);
+
+        [Fact]
+        public void OneInverseTransform_WithoutHardwareIntrinsics_Works() => FeatureTestRunner.RunWithHwIntrinsicsFeature(RunOneInverseTransformTest, HwIntrinsics.DisableHWIntrinsic);
+
+        [Fact]
+        public void TwoInverseTransform_WithHardwareIntrinsics_Works() => FeatureTestRunner.RunWithHwIntrinsicsFeature(RunTwoInverseTransformTest, HwIntrinsics.AllowAll);
 
         [Fact]
-        public void InverseTransform_WithoutHardwareIntrinsics_Works() => FeatureTestRunner.RunWithHwIntrinsicsFeature(RunInverseTransformTest, HwIntrinsics.DisableHWIntrinsic);
+        public void TwoInverseTransform_WithoutHardwareIntrinsics_Works() => FeatureTestRunner.RunWithHwIntrinsicsFeature(RunTwoInverseTransformTest, HwIntrinsics.DisableHWIntrinsic);
 #endif
     }
 }