Test against NET 9

.github/workflows/build-and-test.yml

@@ -19,6 +19,31 @@ jobs:
         isARM:
           - ${{ contains(github.event.pull_request.labels.*.name, 'arch:arm32') || contains(github.event.pull_request.labels.*.name, 'arch:arm64') }}
         options:
+          - os: ubuntu-latest
+            framework: net9.0
+            sdk: 9.0.x
+            sdk-preview: true
+            runtime: -x64
+            codecov: false
+          - os: macos-13 # macos-latest runs on arm64 runners where libgdiplus is unavailable
+            framework: net9.0
+            sdk: 9.0.x
+            sdk-preview: true
+            runtime: -x64
+            codecov: false
+          - os: windows-latest
+            framework: net9.0
+            sdk: 9.0.x
+            sdk-preview: true
+            runtime: -x64
+            codecov: false
+          - os: buildjet-4vcpu-ubuntu-2204-arm
+            framework: net9.0
+            sdk: 9.0.x
+            sdk-preview: true
+            runtime: -x64
+            codecov: false
+
           - os: ubuntu-latest
             framework: net8.0
             sdk: 8.0.x
@@ -100,7 +125,7 @@ jobs:
         uses: actions/setup-dotnet@v4
         with:
           dotnet-version: |
-            8.0.x
+            9.0.x
 
       - name: DotNet Build
         if: ${{ matrix.options.sdk-preview != true }}

src/ImageSharp/ImageSharp.csproj

@@ -13,6 +13,7 @@
     <PackageTags>Image Resize Crop Gif Jpg Jpeg Bitmap Pbm Png Tga Tiff WebP NetCore</PackageTags>
     <Description>A new, fully featured, fully managed, cross-platform, 2D graphics API for .NET</Description>
     <Configurations>Debug;Release</Configurations>
+    <IsTrimmable>true</IsTrimmable>
   </PropertyGroup>
 
   <!--  This enables the nullable analysis and treats all nullable warnings as error-->
@@ -29,14 +30,12 @@
   <Choose>
     <When Condition="$(SIXLABORS_TESTING_PREVIEW) == true">
       <PropertyGroup>
-        <TargetFrameworks>net8.0</TargetFrameworks>
-        <IsTrimmable>true</IsTrimmable>
+        <TargetFrameworks>net8.0;net9.0</TargetFrameworks>
       </PropertyGroup>
     </When>
     <Otherwise>
       <PropertyGroup>
         <TargetFrameworks>net8.0</TargetFrameworks>
-        <IsTrimmable>true</IsTrimmable>
       </PropertyGroup>
     </Otherwise>
   </Choose>

tests/ImageSharp.Benchmarks/ImageSharp.Benchmarks.csproj

@@ -23,7 +23,7 @@
   <Choose>
     <When Condition="$(SIXLABORS_TESTING_PREVIEW) == true">
       <PropertyGroup>
-        <TargetFrameworks>net8.0</TargetFrameworks>
+        <TargetFrameworks>net8.0;net9.0</TargetFrameworks>
       </PropertyGroup>
     </When>
     <Otherwise>

tests/ImageSharp.Tests.ProfilingSandbox/ImageSharp.Tests.ProfilingSandbox.csproj

@@ -19,7 +19,7 @@
   <Choose>
     <When Condition="$(SIXLABORS_TESTING_PREVIEW) == true">
       <PropertyGroup>
-        <TargetFrameworks>net8.0</TargetFrameworks>
+        <TargetFrameworks>net8.0;net9.0</TargetFrameworks>
       </PropertyGroup>
     </When>
     <Otherwise>

tests/ImageSharp.Tests/Formats/Tiff/TiffDecoderTests.cs

@@ -719,7 +719,7 @@ public class TiffDecoderTests : TiffDecoderBaseTester
         // ImageMagick cannot decode this image.
         image.DebugSave(provider);
         image.CompareToReferenceOutput(
-            ImageComparer.Exact,
+            ImageComparer.TolerantPercentage(0.0018F), // NET 9+ Uses zlib-ng to decompress, which manages to decode 2 extra pixels.
             provider,
             appendPixelTypeToFileName: false);
     }

tests/ImageSharp.Tests/ImageSharp.Tests.csproj

@@ -12,7 +12,7 @@
   <Choose>
     <When Condition="$(SIXLABORS_TESTING_PREVIEW) == true">
       <PropertyGroup>
-        <TargetFrameworks>net8.0</TargetFrameworks>
+        <TargetFrameworks>net8.0;net9.0</TargetFrameworks>
       </PropertyGroup>
     </When>
     <Otherwise>