Expose test arguments as filterable properties

TUnit.Engine.Tests/FilterByArgumentValueFilteringTests.cs

@@ -0,0 +1,21 @@
+using Shouldly;
+using TUnit.Engine.Tests.Enums;
+
+namespace TUnit.Engine.Tests;
+
+public class FilterByArgumentValueFilteringTests(TestMode testMode) : InvokableTestBase(testMode)
+{
+    [Test]
+    public async Task ExactMatch()
+    {
+        await RunTestsWithFilter(
+            "/*/*/FilterByArgumentValueTests/*[arg0=beta]",
+            [
+                result => result.ResultSummary.Outcome.ShouldBe("Completed"),
+                result => result.ResultSummary.Counters.Total.ShouldBe(1),
+                result => result.ResultSummary.Counters.Passed.ShouldBe(1),
+                result => result.ResultSummary.Counters.Failed.ShouldBe(0),
+                result => result.ResultSummary.Counters.NotExecuted.ShouldBe(0)
+            ]);
+    }
+}

TUnit.Engine/Building/TestBuilder.cs

@@ -1125,6 +1125,16 @@ private Task InvokeDiscoveryEventReceiversAsync(TestContext context)
             context.Metadata.TestDetails.TestName,
             context);
 
+        // Expose the resolved method argument values as filterable properties so
+        // callers can use `--treenode-filter` with syntax like `MyTest[arg0=*foo*]`
+        // to target a specific parameterized instance.
+        var testMethodArguments = context.Metadata.TestDetails.TestMethodArguments;
+        for (var i = 0; i < testMethodArguments.Length; i++)
+        {
+            var argValue = testMethodArguments[i]?.ToString() ?? "";
+            discoveredContext.AddProperty($"arg{i}", argValue);
+        }
+
         return _eventReceiverOrchestrator.InvokeTestDiscoveryEventReceiversAsync(context, discoveredContext, CancellationToken.None);
     }
 

TUnit.TestProject/FilterByArgumentValueTests.cs

@@ -0,0 +1,12 @@
+namespace TUnit.TestProject;
+
+public class FilterByArgumentValueTests
+{
+    [Test]
+    [Arguments("alpha")]
+    [Arguments("beta")]
+    [Arguments("gamma")]
+    public void Test(string value)
+    {
+    }
+}