Add Browser platform support to OS enum and RunOn/ExcludeOn attributes with WebAssembly compatibility fixes (#2965)

* Initial plan: Add Browser platform support

Co-authored-by: thomhurst <[email protected]>

* Add Browser platform support to OS enum and attributes

Co-authored-by: thomhurst <[email protected]>

* Complete Browser platform support implementation

Co-authored-by: thomhurst <[email protected]>

* Fix browser platform compatibility issues with Console and Threading APIs

Co-authored-by: thomhurst <[email protected]>

* Add missing Engine test and update public API snapshots for Browser platform support

Co-authored-by: thomhurst <[email protected]>

---------

Co-authored-by: copilot-swe-agent[bot] <[email protected]>
Co-authored-by: thomhurst <[email protected]>

Author: Copilot

Library.props

@@ -16,4 +16,8 @@
         <AssemblyOriginatorKeyFile>$(MSBuildThisFileDirectory)strongname.snk</AssemblyOriginatorKeyFile>
         <PublicKey>0024000004800000940000000602000000240000525341310004000001000100698a70398fa0b2230c5a72e3bd9d56b48f809f6173e49a19fbb942d621be93ad48c5566b47b28faabc359b9ad3ff4e00bbdea88f5bdfa250f391fedd28182b2e37b55d429c0151a42a98ea7a5821818cd15a79fef9903e8607a88304cf3e0317bf86ec96e32e1381535a6582251e5a6eed40b5a3ed82bc444598b1269cce57a7</PublicKey>
     </PropertyGroup>
+
+    <ItemGroup>
+        <SupportedPlatform Include="browser" />
+    </ItemGroup>
 </Project>

TUnit.Core/Attributes/TestMetadata/ExcludeOnAttribute.cs

@@ -35,7 +35,7 @@ namespace TUnit.Core;
 /// }
 ///
 /// // Skip on all supported platforms (essentially always skips the test)
-/// [Test, ExcludeOn(OS.Windows | OS.Linux | OS.MacOs)]
+/// [Test, ExcludeOn(OS.Windows | OS.Linux | OS.MacOs | OS.Browser)]
 /// public void NeverRunTest()
 /// {
 ///     // This test will not run on any supported platform
@@ -57,8 +57,9 @@ public override Task<bool> ShouldSkip(TestRegisteredContext context)
             // Only validate Linux and macOS on .NET 5+ where these OS flags are available
             || (OperatingSystem.HasFlag(OS.Linux) && RuntimeInformation.IsOSPlatform(OSPlatform.Linux))
             || (OperatingSystem.HasFlag(OS.MacOs) && RuntimeInformation.IsOSPlatform(OSPlatform.OSX))
+            || (OperatingSystem.HasFlag(OS.Browser) && System.OperatingSystem.IsBrowser())
 #endif
-            || true;
+            ;
 
         // Return true if the test should be skipped (if we're on an excluded OS)
         return Task.FromResult(shouldSkip);

TUnit.Core/Attributes/TestMetadata/RunOnAttribute.cs

@@ -35,7 +35,7 @@ namespace TUnit.Core;
 /// }
 ///
 /// // Run on all supported platforms
-/// [Test, RunOn(OS.Windows | OS.Linux | OS.MacOs)]
+/// [Test, RunOn(OS.Windows | OS.Linux | OS.MacOs | OS.Browser)]
 /// public void AllPlatformsTest()
 /// {
 ///     // This test will run on all supported platforms
@@ -64,6 +64,12 @@ public override Task<bool> ShouldSkip(TestRegisteredContext context)
         {
             return Task.FromResult(false);
         }
+
+        // Check for Browser platform (WebAssembly)
+        if (OperatingSystem.HasFlag(OS.Browser) && System.OperatingSystem.IsBrowser())
+        {
+            return Task.FromResult(false);
+        }
 #endif
 
         return Task.FromResult(true);

TUnit.Core/EngineCancellationToken.cs

@@ -27,7 +27,15 @@ internal void Initialise(CancellationToken cancellationToken)
         CancellationTokenSource = CancellationTokenSource.CreateLinkedTokenSource(cancellationToken);
         Token = CancellationTokenSource.Token;
 
-        Console.CancelKeyPress += OnCancelKeyPress;
+        // Console.CancelKeyPress is not supported on browser platforms
+#if NET5_0_OR_GREATER
+        if (!OperatingSystem.IsBrowser())
+        {
+#endif
+            Console.CancelKeyPress += OnCancelKeyPress;
+#if NET5_0_OR_GREATER
+        }
+#endif
     }
 
     private void OnCancelKeyPress(object? sender, ConsoleCancelEventArgs e)
@@ -68,7 +76,15 @@ private void OnCancelKeyPress(object? sender, ConsoleCancelEventArgs e)
     /// </summary>
     public void Dispose()
     {
-        Console.CancelKeyPress -= OnCancelKeyPress;
+        // Console.CancelKeyPress is not supported on browser platforms
+#if NET5_0_OR_GREATER
+        if (!OperatingSystem.IsBrowser())
+        {
+#endif
+            Console.CancelKeyPress -= OnCancelKeyPress;
+#if NET5_0_OR_GREATER
+        }
+#endif
         _forcefulExitCts?.Cancel();
         _forcefulExitCts?.Dispose();
         CancellationTokenSource.Dispose();

TUnit.Core/Enums/OS.cs

@@ -22,7 +22,7 @@
 /// [RunOn(OS.Windows | OS.Linux)]
 /// 
 /// // Specify a test should run on all supported platforms
-/// [RunOn(OS.Windows | OS.Linux | OS.MacOs)]
+/// [RunOn(OS.Windows | OS.Linux | OS.MacOs | OS.Browser)]
 /// </code>
 /// </example>
 /// <seealso cref="RunOnAttribute"/>
@@ -51,5 +51,13 @@ public enum OS
     /// <remarks>
     /// Tests with this flag will be executed on macOS platforms when used with <see cref="RunOnAttribute"/>.
     /// </remarks>
-    MacOs = 4
+    MacOs = 4,
+
+    /// <summary>
+    /// Represents the Browser platform (WebAssembly).
+    /// </summary>
+    /// <remarks>
+    /// Tests with this flag will be executed on Browser platforms when used with <see cref="RunOnAttribute"/>.
+    /// </remarks>
+    Browser = 8
 }

TUnit.Core/Executors/DedicatedThreadExecutor.cs

@@ -7,6 +7,15 @@ public class DedicatedThreadExecutor : GenericAbstractExecutor, ITestRegisteredE
 {
     protected sealed override async ValueTask ExecuteAsync(Func<ValueTask> action)
     {
+        // On browser platforms, threading is not supported, so fall back to direct execution
+#if NET5_0_OR_GREATER
+        if (OperatingSystem.IsBrowser())
+        {
+            await action();
+            return;
+        }
+#endif
+
         var tcs = new TaskCompletionSource<object?>();
 
         var thread = new Thread(() =>

TUnit.Engine/Logging/TUnitFrameworkLogger.cs

@@ -76,7 +76,16 @@ private static ConsoleColor GetConsoleColor(LogLevel logLevel)
             return ConsoleColor.DarkRed;
         }
 
+        // Console.ForegroundColor is not supported on browser platforms
+#if NET5_0_OR_GREATER
+        if (!OperatingSystem.IsBrowser())
+        {
+            return Console.ForegroundColor;
+        }
+        return ConsoleColor.Gray; // Default color for browser platforms
+#else
         return Console.ForegroundColor;
+#endif
     }
 
     public bool IsEnabled(LogLevel logLevel)

TUnit.PublicAPI/Tests.Core_Library_Has_No_API_Changes.DotNet8_0.verified.txt

@@ -1695,6 +1695,7 @@ namespace .Enums
         Linux = 1,
         Windows = 2,
         MacOs = 4,
+        Browser = 8,
     }
     public enum Priority
     {

TUnit.PublicAPI/Tests.Core_Library_Has_No_API_Changes.DotNet9_0.verified.txt

@@ -1695,6 +1695,7 @@ namespace .Enums
         Linux = 1,
         Windows = 2,
         MacOs = 4,
+        Browser = 8,
     }
     public enum Priority
     {

TUnit.PublicAPI/Tests.Core_Library_Has_No_API_Changes.Net4_7.verified.txt

@@ -1607,6 +1607,7 @@ namespace .Enums
         Linux = 1,
         Windows = 2,
         MacOs = 4,
+        Browser = 8,
     }
     public enum Priority
     {