feat(suppression): automatically unsuppress and re-suppress tests on GitHub issue events

app_dart/lib/cocoon_service.dart

@@ -63,6 +63,8 @@ export 'src/service/flags/ordered_presubmit_flags.dart';
 export 'src/service/flags/unified_check_run_flow_flags.dart';
 export 'src/service/gerrit_service.dart';
 export 'src/service/github_checks_service.dart';
+export 'src/service/issue_service.dart';
 export 'src/service/luci_build_service.dart';
 export 'src/service/pull_request_manager.dart';
 export 'src/service/scheduler.dart';
+export 'src/service/test_suppression.dart';

app_dart/lib/server.dart

@@ -27,7 +27,6 @@ import 'src/service/content_aware_hash_service.dart';
 import 'src/service/discord_service.dart';
 import 'src/service/log_analyzer.dart';
 import 'src/service/scheduler/ci_yaml_fetcher.dart';
-import 'src/service/test_suppression.dart';
 
 typedef Server = Future<void> Function(Request);
 
@@ -66,6 +65,11 @@ Server createServer({
     cache: cache,
   );
 
+  final issueService = IssueService(
+    firestore: firestore,
+    suppressionService: suppressionService,
+  );
+
   final handlers = <String, RequestHandler>{
     '/api/analyze-logs': AnalyzeLogs(
       config: config,
@@ -110,6 +114,7 @@ Server createServer({
       scheduler: scheduler,
       commitService: commitService,
       firestore: firestore,
+      issueService: issueService,
     ),
     '/api/v2/presubmit-luci-subscription': PresubmitLuciSubscription(
       cache: cache,

app_dart/lib/src/model/firestore/suppressed_test.dart

@@ -64,9 +64,18 @@ final class SuppressedTest extends AppDocument<SuppressedTest> {
       '$fieldRepository =': repository,
       '$fieldIsSuppressed =': true,
     });
-    return docs.isEmpty
-        ? []
-        : [for (final doc in docs) SuppressedTest.fromDocument(doc)];
+    return [for (final doc in docs) SuppressedTest.fromDocument(doc)];
+  }
+
+  /// Returns all [SuppressedTest] documents matching [issueLink].
+  static Future<List<SuppressedTest>> getByIssueLink(
+    FirestoreService firestore,
+    String issueLink,
+  ) async {
+    final docs = await firestore.query(kCollectionId, {
+      '$fieldIssueLink =': issueLink,
+    });
+    return [for (final doc in docs) SuppressedTest.fromDocument(doc)];
   }
 
   /// Creates a new [SuppressedTest] document.
@@ -93,39 +102,47 @@ final class SuppressedTest extends AppDocument<SuppressedTest> {
   }
 
   /// The misbehaving test.
-  String get testName => fields[fieldName]!.stringValue!;
+  String get testName => fields[fieldName]?.stringValue ?? '';
 
   /// The repository this test is evaluated with.
-  String get repository => fields[fieldRepository]!.stringValue!;
+  String get repository => fields[fieldRepository]?.stringValue ?? '';
 
   /// A required github issue link describing why the test is suppressed.
-  String get issueLink => fields[fieldIssueLink]!.stringValue!;
+  String get issueLink => fields[fieldIssueLink]?.stringValue ?? '';
 
   /// Whether this test is currently suppressed.
-  bool get isSuppressed => fields[fieldIsSuppressed]!.booleanValue!;
+  bool get isSuppressed => fields[fieldIsSuppressed]?.booleanValue ?? false;
 
   /// When this document was created.
-  DateTime get createTimestamp =>
-      DateTime.parse(fields[fieldCreateTimestamp]!.timestampValue!);
+  DateTime get createTimestamp {
+    final timestamp = fields[fieldCreateTimestamp]?.timestampValue;
+    return timestamp != null
+        ? DateTime.parse(timestamp)
+        : DateTime.fromMillisecondsSinceEpoch(0);
+  }
 
   /// A list of updates to this document for audit purposes.
   List<Map<String, dynamic>> get updates {
     final values = fields[fieldUpdates]?.arrayValue?.values;
     if (values == null) {
       return const [];
     }
-    return [...values.map(_valueToUpdateMap)];
+    return [for (final value in values) _valueToUpdateMap(value)];
   }
 
   static Map<String, dynamic> _valueToUpdateMap(Value value) {
-    final fields = value.mapValue!.fields!;
+    final fields = value.mapValue?.fields;
+    if (fields == null) {
+      return const {};
+    }
     return {
-      updateFieldUser: fields[updateFieldUser]!.stringValue!,
-      updateFieldUpdateTimestamp: DateTime.parse(
-        fields[updateFieldUpdateTimestamp]!.timestampValue!,
-      ),
-      updateFieldNote: fields[updateFieldNote]!.stringValue!,
-      updateFieldAction: fields[updateFieldAction]!.stringValue!,
+      updateFieldUser: fields[updateFieldUser]?.stringValue ?? '',
+      updateFieldUpdateTimestamp:
+          fields[updateFieldUpdateTimestamp]?.timestampValue != null
+          ? DateTime.parse(fields[updateFieldUpdateTimestamp]!.timestampValue!)
+          : DateTime.fromMillisecondsSinceEpoch(0),
+      updateFieldNote: fields[updateFieldNote]?.stringValue ?? '',
+      updateFieldAction: fields[updateFieldAction]?.stringValue ?? '',
     };
   }
 }

app_dart/lib/src/request_handlers/github/webhook_subscription.dart

@@ -43,6 +43,7 @@ final class GithubWebhookSubscription extends SubscriptionHandler {
     required this.gerritService,
     required this.commitService,
     required this.firestore,
+    this.issueService,
     super.authProvider,
     this.pullRequestLabelProcessorProvider = PullRequestLabelProcessor.new,
     @visibleForTesting DateTime Function() now = DateTime.now,
@@ -63,6 +64,7 @@ final class GithubWebhookSubscription extends SubscriptionHandler {
 
   final FirestoreService firestore;
   final PullRequestLabelProcessorProvider pullRequestLabelProcessorProvider;
+  final IssueService? issueService;
 
   @override
   Future<Response> post(Request request) async {
@@ -78,6 +80,8 @@ final class GithubWebhookSubscription extends SubscriptionHandler {
     switch (webhook.event) {
       case 'pull_request':
         return _handlePullRequest(webhook.payload);
+      case 'issues':
+        return _handleIssues(webhook.payload);
       case 'merge_group':
         final result = await _handleMergeGroup(
           webhook.payload,
@@ -417,6 +421,26 @@ final class GithubWebhookSubscription extends SubscriptionHandler {
     }
   }
 
+  Future<Response> _handleIssues(String rawRequest) async {
+    final issueEvent = _getIssueEvent(rawRequest);
+    if (issueEvent == null) {
+      throw const BadRequestException('Expected issue event.');
+    }
+    if (issueService case final service?) {
+      await service.handleIssueEvent(issueEvent);
+    }
+    return Response.emptyOk;
+  }
+
+  IssueEvent? _getIssueEvent(String request) {
+    try {
+      return IssueEvent.fromJson(jsonDecode(request) as Map<String, dynamic>);
+    } catch (e, s) {
+      log.warn('_getIssueEvent: Failed to parse $request', e, s);
+      return null;
+    }
+  }
+
   LabeledEvent? _getLabeledEvent(String request) {
     try {
       return LabeledEvent.fromJson(

app_dart/lib/src/request_handlers/update_suppressed_test.dart

@@ -8,8 +8,6 @@ import 'package:github/github.dart';
 import '../../cocoon_service.dart';
 import '../request_handling/api_request_handler.dart';
 import '../request_handling/exceptions.dart';
-import '../service/test_suppression.dart'
-    show SuppressingAction, TestSuppression;
 
 /// Manually updates the test suppression status.
 ///
@@ -97,16 +95,17 @@ final class UpdateSuppressedTest extends ApiRequestHandler {
           'Parameter "$_paramIssueLink" must be a string',
         );
       }
-      issueLink = link;
 
-      // Validate issue link
-      final issueNumber = _parseIssueNumber(issueLink);
-      if (issueNumber == null) {
+      final canonicalUrl = TestSuppression.canonicalizeIssueUrl(link);
+      if (canonicalUrl == null) {
         throw const BadRequestException(
           'Invalid issue link format, expected https://github.com/flutter/flutter/issues/1234',
         );
       }
 
+      issueLink = canonicalUrl;
+      final issueNumber = int.parse(Uri.parse(canonicalUrl).pathSegments.last);
+
       final githubService = await config.createGithubService(repository);
       final Issue? issue;
       try {
@@ -146,19 +145,4 @@ final class UpdateSuppressedTest extends ApiRequestHandler {
 
     return Response.emptyOk;
   }
-
-  int? _parseIssueNumber(String issueLink) {
-    // Expected format: https://github.com/flutter/flutter/issues/123456
-    final uri = Uri.tryParse(issueLink);
-    if (uri == null ||
-        uri.host != 'github.com' ||
-        uri.pathSegments.length < 4 ||
-        uri.pathSegments[uri.pathSegments.length - 2] != 'issues') {
-      return null;
-    }
-
-    // Path segments: [flutter, flutter, issues, 123456]
-    // Or just check the last segment if it is a number
-    return int.tryParse(uri.pathSegments.last);
-  }
 }

app_dart/lib/src/service/issue_service.dart

@@ -0,0 +1,111 @@
+// Copyright 2026 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'package:cocoon_server/logging.dart';
+import 'package:github/github.dart';
+import 'package:github/hooks.dart';
+
+import '../model/firestore/suppressed_test.dart';
+import 'firestore.dart';
+import 'test_suppression.dart';
+
+/// Processes GitHub issue events to unsuppress or re-suppress matching tests.
+final class IssueService {
+  const IssueService({
+    required this.firestore,
+    required this.suppressionService,
+  });
+
+  final FirestoreService firestore;
+  final TestSuppression suppressionService;
+
+  /// Re-opens or closes suppressed tests matching a GitHub [IssueEvent].
+  Future<void> handleIssueEvent(IssueEvent event) async {
+    if (event.issue?.htmlUrl case final issueUrl? when issueUrl.isNotEmpty) {
+      switch (event.action) {
+        case 'closed':
+          await _handleIssueClosed(event, issueUrl);
+        case 'reopened':
+          await _handleIssueReopened(event, issueUrl);
+        case final action:
+          log.debug('Ignoring issue event action: $action');
+      }
+      return;
+    }
+    log.debug('IssueEvent has no htmlUrl; skipping.');
+  }
+
+  Future<void> _handleIssueClosed(IssueEvent event, String issueUrl) async {
+    final docs = await SuppressedTest.getByIssueLink(firestore, issueUrl);
+    final processed = <String>{};
+
+    for (final doc in docs) {
+      // Tests can be suppressed at different times; we only need to handle
+      // this event once per unique test.
+      final key = '${doc.repository}/${doc.testName}';
+      if (!processed.add(key)) {
+        continue;
+      }
+
+      final latest = await SuppressedTest.getLatest(
+        firestore,
+        doc.repository,
+        doc.testName,
+      );
+      if (latest == null ||
+          latest.issueLink != issueUrl ||
+          !latest.isSuppressed) {
+        continue;
+      }
+
+      log.info(
+        'Unsuppressing test ${doc.testName} in ${doc.repository} due to issue closed ($issueUrl)',
+      );
+      await suppressionService.updateSuppression(
+        testName: doc.testName,
+        email: event.sender?.login ?? 'github-webhook',
+        repository: RepositorySlug.full(doc.repository),
+        action: SuppressingAction.unsuppress,
+        note: 'Automatic unsuppression: issue $issueUrl was closed.',
+      );
+    }
+  }
+
+  Future<void> _handleIssueReopened(IssueEvent event, String issueUrl) async {
+    final docs = await SuppressedTest.getByIssueLink(firestore, issueUrl);
+    final processed = <String>{};
+
+    for (final doc in docs) {
+      // Tests can be suppressed at different times; we only need to handle
+      // this event once per unique test.
+      final key = '${doc.repository}/${doc.testName}';
+      if (!processed.add(key)) {
+        continue;
+      }
+
+      final latest = await SuppressedTest.getLatest(
+        firestore,
+        doc.repository,
+        doc.testName,
+      );
+      if (latest == null ||
+          latest.issueLink != issueUrl ||
+          latest.isSuppressed) {
+        continue;
+      }
+
+      log.info(
+        'Re-suppressing test ${doc.testName} in ${doc.repository} due to issue reopened ($issueUrl)',
+      );
+      await suppressionService.updateSuppression(
+        testName: doc.testName,
+        email: event.sender?.login ?? 'github-webhook',
+        repository: RepositorySlug.full(doc.repository),
+        action: SuppressingAction.suppress,
+        issueLink: issueUrl,
+        note: 'Automatic re-suppression: issue $issueUrl was reopened.',
+      );
+    }
+  }
+}

app_dart/lib/src/service/test_suppression.dart

@@ -99,12 +99,23 @@ class TestSuppression {
         return;
       }
 
+      if (issueLink == null) {
+        throw ArgumentError.notNull('issueLink');
+      }
+
+      final canonicalLink = canonicalizeIssueUrl(issueLink);
+      if (canonicalLink == null) {
+        throw ArgumentError.value(
+          issueLink,
+          'issueLink',
+          'Invalid GitHub issue URL format. Expected https://github.com/<owner>/<repo>/issues/<number>',
+        );
+      }
+
       final newSuppression = SuppressedTest(
         name: testName,
         repository: repository.fullName,
-        issueLink:
-            issueLink ??
-            'BUG: You have found a bug! Please report to https://www.github.com/flutter/flutter/issues/new',
+        issueLink: canonicalLink,
         isSuppressed: true,
         createTimestamp: now,
         updates: [updateEntry],
@@ -124,6 +135,35 @@ class TestSuppression {
     );
   }
 
+  /// Canonicalizes a GitHub issue URL into `https://github.com/<owner>/<repo>/issues/<issue_number>`.
+  ///
+  /// Strips fragment anchors (e.g. `#issuecomment-123456`), query parameters, subpaths,
+  /// and trailing slashes. Returns `null` if the URL cannot be parsed into a valid GitHub issue link.
+  static String? canonicalizeIssueUrl(String issueUrl) {
+    final trimmed = issueUrl.trim();
+    if (Uri.tryParse(trimmed) case Uri(
+      :final host,
+      :final pathSegments,
+    ) when host == 'github.com' || host == 'www.github.com') {
+      final segments = [
+        for (final s in pathSegments)
+          if (s.isNotEmpty) s,
+      ];
+      if (segments case [
+        final owner,
+        final repo,
+        'issues',
+        final issueNumber,
+        ...,
+      ]) {
+        if (int.tryParse(issueNumber) != null) {
+          return 'https://github.com/$owner/$repo/issues/$issueNumber';
+        }
+      }
+    }
+    return null;
+  }
+
   Future<bool> isTestSuppressed({
     required String testName,
     required RepositorySlug repository,