Added a check to the analyzer script to detect skipped tests. (#88003)

Added a check to the analyzer script to detect skipped tests that aren't commented.

The comment following the `skip` parameter should include either a link to a
github issue tracking the reenabling of the test, or a '[intended]' tag with
a brief description of why the test should never be enabled for the given
condition.

dev/bots/analyze.dart

diff --git a/dev/bots/analyze.dart b/dev/bots/analyze.dart
index 0fa978b..7323a5b 100644
--- a/dev/bots/analyze.dart
+++ b/dev/bots/analyze.dart
@@ -60,6 +60,9 @@
   print('$clock Deprecations...');
   await verifyDeprecations(flutterRoot);
 
+  print('$clock Skip test comments...');
+  await verifySkipTestComments(flutterRoot);
+
   print('$clock Licenses...');
   await verifyNoMissingLicense(flutterRoot);
 
@@ -280,6 +283,38 @@
   }
 }
 
+final RegExp _skipTestCommentPattern = RegExp(r'\bskip:.*?//(.*)');
+const Pattern _skipTestIntentionalPattern = '[intended]';
+final Pattern _skipTestTrackingBugPattern = RegExp(r'https+?://github.com/.*/issues/[0-9]+');
+
+Future<void> verifySkipTestComments(String workingDirectory) async {
+  final List<String> errors = <String>[];
+  final Stream<File> testFiles = _allFiles(workingDirectory, 'dart', minimumMatches: 1500)
+    .where((File f) => f.path.endsWith('_test.dart'));
+
+  await for (final File file in testFiles) {
+    final List<String> lines = file.readAsLinesSync();
+    for (int index = 0; index < lines.length; index++) {
+      final Match? match = _skipTestCommentPattern.firstMatch(lines[index]);
+      final String? skipComment = match?.group(1);
+      if (skipComment != null
+          && !skipComment.contains(_skipTestIntentionalPattern)
+          && !skipComment.contains(_skipTestTrackingBugPattern)) {
+        final int sourceLine = index + 1;
+        errors.add('${file.path}:$sourceLine}: skip test without a justification comment.');
+      }
+    }
+  }
+
+  // Fail if any errors
+  if (errors.isNotEmpty) {
+    exitWithError(<String>[
+      ...errors,
+      '\n${bold}See: https://github.com/flutter/flutter/wiki/Tree-hygiene#skipped-tests$reset',
+    ]);
+  }
+}
+
 final RegExp _testImportPattern = RegExp(r'''import (['"])([^'"]+_test\.dart)\1''');
 const Set<String> _exemptTestImports = <String>{
   'package:flutter_test/flutter_test.dart',