Change percentages for mac

tests/ImageSharp.Tests/Formats/Gif/GifDecoderTests.cs

@@ -56,7 +56,7 @@ namespace SixLabors.ImageSharp.Tests.Formats.Gif
 
             image.DebugSave(provider, testOutputDetails: details, appendPixelTypeToFileName: false);
             image.CompareToReferenceOutput(
-                ImageComparer.Exact,
+                ImageComparer.TolerantPercentage(0.0001F),
                 provider,
                 testOutputDetails: details,
                 appendPixelTypeToFileName: false);

tests/ImageSharp.Tests/Formats/Tga/TgaDecoderTests.cs

@@ -764,7 +764,7 @@ namespace SixLabors.ImageSharp.Tests.Formats.Tga
 
             image.DebugSave(provider, testOutputDetails: details, appendPixelTypeToFileName: false);
             image.CompareToReferenceOutput(
-                ImageComparer.Exact,
+                ImageComparer.TolerantPercentage(0.0001F),
                 provider,
                 testOutputDetails: details,
                 appendPixelTypeToFileName: false);

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

@@ -372,7 +372,7 @@ namespace SixLabors.ImageSharp.Tests.Formats.Webp
 
             image.DebugSave(provider, testOutputDetails: details, appendPixelTypeToFileName: false);
             image.CompareToReferenceOutput(
-                ImageComparer.Exact,
+                ImageComparer.TolerantPercentage(0.0006F),
                 provider,
                 testOutputDetails: details,
                 appendPixelTypeToFileName: false);

tests/ImageSharp.Tests/TestUtilities/ImageComparison/Exceptions/ImageDifferenceIsOverThresholdException.cs

@@ -24,8 +24,7 @@ namespace SixLabors.ImageSharp.Tests.TestUtilities.ImageComparison
 
             sb.Append(Environment.NewLine);
 
-            // TODO: We should add macOS.
-            sb.AppendFormat("Test Environment OS : {0}", TestEnvironment.IsWindows ? "Windows" : "Linux");
+            sb.AppendFormat("Test Environment OS : {0}", GetEnvironmentName());
             sb.Append(Environment.NewLine);
 
             sb.AppendFormat("Test Environment is CI : {0}", TestEnvironment.RunsOnCI);
@@ -33,11 +32,14 @@ namespace SixLabors.ImageSharp.Tests.TestUtilities.ImageComparison
 
             sb.AppendFormat("Test Environment is .NET Core : {0}", !TestEnvironment.IsFramework);
             sb.Append(Environment.NewLine);
+            
+            sb.AppendFormat("Test Environment is Mono : {0}", TestEnvironment.IsMono);
+            sb.Append(Environment.NewLine);
 
             int i = 0;
             foreach (ImageSimilarityReport r in reports)
             {
-                sb.Append($"Report ImageFrame {i}: ");
+                sb.Append("Report ImageFrame {i}: ");
                 sb.Append(r);
                 sb.Append(Environment.NewLine);
                 i++;
@@ -45,5 +47,25 @@ namespace SixLabors.ImageSharp.Tests.TestUtilities.ImageComparison
 
             return sb.ToString();
         }
+
+        private static string GetEnvironmentName()
+        {
+            if (TestEnvironment.IsMacOS)
+            {
+                return "Mac OS";
+            }
+
+            if (TestEnvironment.IsMacOS)
+            {
+                return "Linux";
+            }
+
+            if (TestEnvironment.IsWindows)
+            {
+                return "Windows";
+            }
+
+            return "Unknown";
+        }
     }
 }