[coverage] Fix another flaky lifecycle management error (#2082)

Author: liamappelbe

pkgs/coverage/CHANGELOG.md

@@ -1,3 +1,8 @@
+## 1.13.1
+
+- Fix a bug where the VM service can be shut down while some coverage
+  collections are still happening.
+
 ## 1.13.0
 
 - Introduced support for minimum coverage thresholds using --fail-under flag in

pkgs/coverage/lib/src/isolate_paused_listener.dart

@@ -27,6 +27,7 @@ class IsolatePausedListener {
   final SyncErrorLogger _log;
 
   final _isolateGroups = <String, IsolateGroupState>{};
+  final _oldCollectionTasks = <Future<void>>{};
 
   int _numIsolates = 0;
   bool _finishedListening = false;
@@ -48,7 +49,7 @@ class IsolatePausedListener {
     _finishedListening = true;
 
     // Collect all remaining uncollected groups.
-    final collectionTasks = <Future<void>>[];
+    final collectionTasks = _oldCollectionTasks.toList();
     for (final group in _isolateGroups.values) {
       if (!group.collected) {
         group.collected = true;
@@ -91,9 +92,13 @@ class IsolatePausedListener {
       if (isLastIsolateInGroup) {
         group.collected = true;
       }
+      Future<void>? collectionTask;
       try {
-        await _onIsolatePaused(isolateRef, isLastIsolateInGroup);
+        collectionTask = _onIsolatePaused(isolateRef, isLastIsolateInGroup);
+        _oldCollectionTasks.add(collectionTask);
+        await collectionTask;
       } finally {
+        _oldCollectionTasks.remove(collectionTask);
         group.exit(isolateRef);
         if (!_finishedListening) {
           await _service.resume(isolateRef.id!);

pkgs/coverage/pubspec.yaml

@@ -1,5 +1,5 @@
 name: coverage
-version: 1.13.0
+version: 1.13.1
 description: Coverage data manipulation and formatting
 repository: https://github.com/dart-lang/tools/tree/main/pkgs/coverage
 issue_tracker: https://github.com/dart-lang/tools/issues?q=is%3Aissue+is%3Aopen+label%3Apackage%3Acoverage

pkgs/coverage/test/isolate_paused_listener_test.dart

@@ -867,15 +867,14 @@ void main() {
       pauseEvent('B', '2');
       pauseEvent('A', '1', 'main');
 
-      while (received.length < 4) {
+      while (received.length < 3) {
         await Future<void>.delayed(Duration.zero);
       }
 
       expect(received, [
         'Pause B. Collect group 2? Yes',
         'Pause A. Collect group 1? Yes',
         'Pause done A',
-        'Resume A',
       ]);
 
       delayingB.complete();
@@ -884,8 +883,9 @@ void main() {
         'Pause B. Collect group 2? Yes',
         'Pause A. Collect group 1? Yes',
         'Pause done A',
-        'Resume A',
         'Pause done B',
+        // A waits for B's pause callback to complete before resuming.
+        'Resume A',
         // Don't try to resume B, because the VM service is already shut down.
       ]);
     });