Don't debug further tests when stopping the debug session (#1797)

* Don't debug further tests when stopping the debug session

* Add changelog entry

Author: award999

CHANGELOG.md

@@ -8,6 +8,10 @@
 - Prompt to cancel and replace the active test run if one is in flight ([#1774](https://github.com/swiftlang/vscode-swift/pull/1774))
 - A walkthrough for first time extension users ([#1560](https://github.com/swiftlang/vscode-swift/issues/1560))
 
+### Fixed
+
+- Don't start debugging XCTest cases if the swift-testing debug session was stopped ([#1797](https://github.com/swiftlang/vscode-swift/pull/1797))
+
 ## 2.11.20250806 - 2025-08-06
 
 ### Added

src/TestExplorer/TestRunner.ts

@@ -700,6 +700,10 @@ export class TestRunner {
             compositeToken.token
         );
 
+        // If the user terminates a debugging session for swift-testing
+        // we want to prevent XCTest from starting.
+        const terminationListener = runner.onDebugSessionTerminated(() => compositeToken.cancel());
+
         // Register the test run with the manager
         folderContext.registerTestRun(runner.testRun, compositeToken);
 
@@ -709,6 +713,8 @@ export class TestRunner {
         // Run the tests
         await runner.runHandler();
 
+        terminationListener.dispose();
+
         // Run the post-run handler if provided
         if (postRunHandler) {
             await postRunHandler(runner);