perf: skip TCS bridge in ExecuteTestAsync when no ExecutionContext is captured

src/Adapter/MSTestAdapter.PlatformServices/Execution/TestMethodRunner.cs

@@ -496,11 +496,27 @@ private async Task<TestResult[]> ExecuteTestAsync(ITestContext executionContext,
  {
  try
  {
+ ExecutionContext? capturedContext = testMethodInfo.Parent.ExecutionContext
+ ?? testMethodInfo.Parent.Parent.ExecutionContext;
+
+ // Fast path: when no ExecutionContext was captured (the common case),
+ // ExecutionContextHelpers.RunOnContext would simply call the action inline.
+ // Skip the TaskCompletionSource bridge, async-lambda closure, and Action
+ // delegate allocations entirely.
+ if (capturedContext is null)
+ {
+ using (TestContextImplementation.SetCurrentTestContext(executionContext as TestContext))
+ {
+ testMethodInfo.TestContext = executionContext;
+ return await _testMethodInfo.Executor.ExecuteAsync(testMethodInfo).ConfigureAwait(false);
+ }
+ }
+
  var tcs = new TaskCompletionSource<TestResult[]>();
 
 #pragma warning disable VSTHRD101 // Avoid unsupported async delegates
  ExecutionContextHelpers.RunOnContext(
-testMethodInfo.Parent.ExecutionContext ?? testMethodInfo.Parent.Parent.ExecutionContext,
+capturedContext,
  async () =>
  {
  try