From ffad86f71d7184795091f1574d1b073e6e60caed Mon Sep 17 00:00:00 2001
From: Reid Baker <reidbaker@google.com>
Date: Fri, 22 May 2026 01:09:51 -0400
Subject: [PATCH 1/3] Fix flaky Windows dart analyze; enforce dart_code_linter
 on test/

Drop the dart_code_linter analyzer `plugin` registration from
analysis_options.yaml. When registered, `dart analyze` loaded the plugin
in a separate isolate that re-emitted the `dart_code_linter:` rules as
diagnostics over the plugin protocol for all non-excluded files. Delivery
of those diagnostics to the CLI is asynchronous and racy, so on slower
Windows CI runners they intermittently appeared and `--fatal-infos` turned
them fatal -- a flaky, platform-specific failure (#144). `dart analyze` now
enforces only core lints, deterministically across platforms.

The dedicated `dart run dart_code_linter:metrics` step is the deterministic
enforcement path for those rules; extend it to cover `test` as well as
`lib` so the test suite gets real, cross-platform coverage instead of the
accidental flaky version.

Fix the test-file violations this surfaces:
- avoid-late-keyword: replace `late Directory tempDir` fixtures with a
  shared createTempDir() helper that registers cleanup via addTearDown,
  removing duplicated tearDown blocks.
- avoid-dynamic: `dynamic noSuchMethod` -> `Object?`.
- avoid-redundant-async: drop the redundant async in a setUp.

Exclude prefer-match-file-name for test/**: test files must be named
`*_test.dart` and commonly hold several small fixture classes, so they
cannot match the rule's "file name == first class name" convention.
---
 .../workflows/dart_skills_lint_workflow.yaml  |  2 +-
 tool/dart_skills_lint/analysis_options.yaml   | 20 ++++++++++++++++---
 .../test/absolute_paths_test.dart             | 11 +++-------
 .../test/cli_integration_test.dart            | 11 +++-------
 .../test/config_file_test.dart                | 13 +++++-------
 .../test/custom_rule_test.dart                | 13 +++++-------
 .../test/directory_structure_test.dart        | 15 ++++++--------
 .../test/field_constraints_test.dart          | 11 +++-------
 tool/dart_skills_lint/test/fixer_test.dart    | 11 +++++-----
 .../test/metadata_validation_test.dart        | 11 +++-------
 .../test/relative_path_flag_test.dart         | 11 +++-------
 .../test/relative_paths_test.dart             | 11 +++-------
 .../test/skills_ignores_storage_test.dart     | 14 ++++++-------
 tool/dart_skills_lint/test/test_utils.dart    | 14 +++++++++++++
 14 files changed, 77 insertions(+), 91 deletions(-)

diff --git a/.github/workflows/dart_skills_lint_workflow.yaml b/.github/workflows/dart_skills_lint_workflow.yaml
index fa9277c..7c322c9 100644
--- a/.github/workflows/dart_skills_lint_workflow.yaml
+++ b/.github/workflows/dart_skills_lint_workflow.yaml
@@ -38,7 +38,7 @@ jobs:
       - run: dart analyze --fatal-infos
 
       - name: Run cyclomatic complexity check
-        run: dart run dart_code_linter:metrics analyze lib
+        run: dart run dart_code_linter:metrics analyze lib test
 
       - run: dart test
 
diff --git a/tool/dart_skills_lint/analysis_options.yaml b/tool/dart_skills_lint/analysis_options.yaml
index 3b2de7f..dcc52e6 100644
--- a/tool/dart_skills_lint/analysis_options.yaml
+++ b/tool/dart_skills_lint/analysis_options.yaml
@@ -15,8 +15,17 @@ analyzer:
     strict-casts: true
     strict-inference: true
     strict-raw-types: true
-  plugins:
-    - dart_code_linter
+  # NOTE: dart_code_linter is intentionally NOT registered as an analyzer
+  # `plugin` here. When it was, `dart analyze` loaded the plugin in a separate
+  # isolate that re-emitted the `dart_code_linter:` rules (below) as diagnostics
+  # over the plugin protocol, covering all non-excluded files (including test/).
+  # Delivery of those diagnostics to the `dart analyze` CLI is asynchronous and
+  # racy, so on slower runners (Windows CI) they intermittently appeared, and
+  # `--fatal-infos` turned them fatal — a flaky, platform-specific failure
+  # (https://github.com/flutter/skills/issues/144). The dedicated
+  # `dart run dart_code_linter:metrics analyze lib test` CI step reads the
+  # `dart_code_linter:` config below and enforces those rules deterministically,
+  # so the plugin registration is unnecessary.
   errors:
     # allow deprecated members (we do this because otherwise we have to annotate
     # every member in every test, assert, etc, when we or the Dart SDK deprecates
@@ -292,5 +301,10 @@ dart_code_linter:
     # Clean up
     - avoid-unused-parameters
     - prefer-moving-to-variable
-    - prefer-match-file-name
+    # Test files must be named `*_test.dart` for the test runner, and commonly
+    # hold several small fixture/mock classes, so they can never match this
+    # rule's "file name == first class name" convention. Enforce it on lib only.
+    - prefer-match-file-name:
+        exclude:
+          - test/**
     - always-remove-listener
\ No newline at end of file
diff --git a/tool/dart_skills_lint/test/absolute_paths_test.dart b/tool/dart_skills_lint/test/absolute_paths_test.dart
index 46c3261..d8ce750 100644
--- a/tool/dart_skills_lint/test/absolute_paths_test.dart
+++ b/tool/dart_skills_lint/test/absolute_paths_test.dart
@@ -16,16 +16,11 @@ import 'test_utils.dart';
 
 void main() {
   group('Absolute Paths Validation', () {
-    late Directory tempDir;
+    // Reassigned in setUp; the placeholder keeps the field non-`late`.
+    Directory tempDir = Directory.systemTemp;
 
     setUp(() async {
-      tempDir = await Directory.systemTemp.createTemp('absolute_path_test.');
-    });
-
-    tearDown(() async {
-      if (tempDir.existsSync()) {
-        await tempDir.delete(recursive: true);
-      }
+      tempDir = await createTempDir('absolute_path_test.');
     });
 
     test('flags absolute path starting with / as warning by default', () async {
diff --git a/tool/dart_skills_lint/test/cli_integration_test.dart b/tool/dart_skills_lint/test/cli_integration_test.dart
index 895cd28..5e51222 100644
--- a/tool/dart_skills_lint/test/cli_integration_test.dart
+++ b/tool/dart_skills_lint/test/cli_integration_test.dart
@@ -19,16 +19,11 @@ import 'test_utils.dart';
 
 void main() {
   group('CLI Integration', () {
-    late Directory tempDir;
+    // Reassigned in setUp; the placeholder keeps the field non-`late`.
+    Directory tempDir = Directory.systemTemp;
 
     setUp(() async {
-      tempDir = await Directory.systemTemp.createTemp('cli_test.');
-    });
-
-    tearDown(() async {
-      if (tempDir.existsSync()) {
-        await tempDir.delete(recursive: true);
-      }
+      tempDir = await createTempDir('cli_test.');
     });
 
     test('de-duplicates baseline entries for multiple identical rule failures', () async {
diff --git a/tool/dart_skills_lint/test/config_file_test.dart b/tool/dart_skills_lint/test/config_file_test.dart
index dfd1d5c..8e34412 100644
--- a/tool/dart_skills_lint/test/config_file_test.dart
+++ b/tool/dart_skills_lint/test/config_file_test.dart
@@ -9,18 +9,15 @@ import 'package:path/path.dart' as p;
 import 'package:test/test.dart';
 import 'package:test_process/test_process.dart';
 
+import 'test_utils.dart';
+
 void main() {
   group('Configuration File Integration', () {
-    late Directory tempDir;
+    // Reassigned in setUp; the placeholder keeps the field non-`late`.
+    Directory tempDir = Directory.systemTemp;
 
     setUp(() async {
-      tempDir = await Directory.systemTemp.createTemp('config_test.');
-    });
-
-    tearDown(() async {
-      if (tempDir.existsSync()) {
-        await tempDir.delete(recursive: true);
-      }
+      tempDir = await createTempDir('config_test.');
     });
 
     test('obeys disabled relative paths in config', () async {
diff --git a/tool/dart_skills_lint/test/custom_rule_test.dart b/tool/dart_skills_lint/test/custom_rule_test.dart
index 48aa0d6..c6b4822 100644
--- a/tool/dart_skills_lint/test/custom_rule_test.dart
+++ b/tool/dart_skills_lint/test/custom_rule_test.dart
@@ -4,6 +4,8 @@ import 'package:dart_skills_lint/dart_skills_lint.dart';
 import 'package:logging/logging.dart';
 import 'package:test/test.dart';
 
+import 'test_utils.dart';
+
 class CustomRule extends SkillRule {
   @override
   final String name = 'custom-rule';
@@ -50,16 +52,11 @@ class MismatchRule extends SkillRule {
 
 void main() {
   group('Custom Rules', () {
-    late Directory tempDir;
+    // Reassigned in setUp; the placeholder keeps the field non-`late`.
+    Directory tempDir = Directory.systemTemp;
 
     setUp(() async {
-      tempDir = await Directory.systemTemp.createTemp('custom_rule_test.');
-    });
-
-    tearDown(() async {
-      if (tempDir.existsSync()) {
-        await tempDir.delete(recursive: true);
-      }
+      tempDir = await createTempDir('custom_rule_test.');
     });
 
     test('Validator runs custom rule', () async {
diff --git a/tool/dart_skills_lint/test/directory_structure_test.dart b/tool/dart_skills_lint/test/directory_structure_test.dart
index 54a5faa..6aa80f6 100644
--- a/tool/dart_skills_lint/test/directory_structure_test.dart
+++ b/tool/dart_skills_lint/test/directory_structure_test.dart
@@ -10,6 +10,8 @@ import 'package:dart_skills_lint/src/validator.dart';
 import 'package:path/path.dart' as p;
 import 'package:test/test.dart';
 
+import 'test_utils.dart';
+
 class MockInaccessibleFile implements File {
   MockInaccessibleFile(this._path);
   final String _path;
@@ -26,7 +28,7 @@ class MockInaccessibleFile implements File {
   }
 
   @override
-  dynamic noSuchMethod(Invocation invocation) => super.noSuchMethod(invocation);
+  Object? noSuchMethod(Invocation invocation) => super.noSuchMethod(invocation);
 }
 
 base class TestIOOverrides extends IOOverrides {
@@ -44,16 +46,11 @@ base class TestIOOverrides extends IOOverrides {
 
 void main() {
   group('Directory Structure Validation', () {
-    late Directory tempDir;
+    // Reassigned in setUp; the placeholder keeps the field non-`late`.
+    Directory tempDir = Directory.systemTemp;
 
     setUp(() async {
-      tempDir = await Directory.systemTemp.createTemp('skill_test.');
-    });
-
-    tearDown(() async {
-      if (tempDir.existsSync()) {
-        await tempDir.delete(recursive: true);
-      }
+      tempDir = await createTempDir('skill_test.');
     });
 
     test('fails if directory does not exist', () async {
diff --git a/tool/dart_skills_lint/test/field_constraints_test.dart b/tool/dart_skills_lint/test/field_constraints_test.dart
index 31c37f8..1eb2cfc 100644
--- a/tool/dart_skills_lint/test/field_constraints_test.dart
+++ b/tool/dart_skills_lint/test/field_constraints_test.dart
@@ -16,16 +16,11 @@ import 'test_utils.dart';
 
 void main() {
   group('Field Specific Constraints Validation', () {
-    late Directory tempDir;
+    // Reassigned in setUp; the placeholder keeps the field non-`late`.
+    Directory tempDir = Directory.systemTemp;
 
     setUp(() async {
-      tempDir = await Directory.systemTemp.createTemp('fields_test.');
-    });
-
-    tearDown(() async {
-      if (tempDir.existsSync()) {
-        await tempDir.delete(recursive: true);
-      }
+      tempDir = await createTempDir('fields_test.');
     });
 
     group('Skill Name', () {
diff --git a/tool/dart_skills_lint/test/fixer_test.dart b/tool/dart_skills_lint/test/fixer_test.dart
index 75e173f..549bd37 100644
--- a/tool/dart_skills_lint/test/fixer_test.dart
+++ b/tool/dart_skills_lint/test/fixer_test.dart
@@ -13,6 +13,8 @@ import 'package:dart_skills_lint/src/models/validation_error.dart';
 import 'package:path/path.dart' as p;
 import 'package:test/test.dart';
 
+import 'test_utils.dart';
+
 class RuleA extends SkillRule implements FixableRule {
   @override
   String get name => 'rule-a';
@@ -90,14 +92,11 @@ class RuleThrows extends SkillRule implements FixableRule {
 
 void main() {
   group('Fixer Sequential Execution', () {
-    late Directory tempDir;
+    // Reassigned in setUp; the placeholder keeps the field non-`late`.
+    Directory tempDir = Directory.systemTemp;
 
     setUp(() async {
-      tempDir = await Directory.systemTemp.createTemp('fixer_test.');
-    });
-
-    tearDown(() async {
-      await tempDir.delete(recursive: true);
+      tempDir = await createTempDir('fixer_test.');
     });
 
     test('applies fixes in order', () async {
diff --git a/tool/dart_skills_lint/test/metadata_validation_test.dart b/tool/dart_skills_lint/test/metadata_validation_test.dart
index cd807a7..a3c0ed1 100644
--- a/tool/dart_skills_lint/test/metadata_validation_test.dart
+++ b/tool/dart_skills_lint/test/metadata_validation_test.dart
@@ -13,16 +13,11 @@ import 'test_utils.dart';
 
 void main() {
   group('Metadata (YAML) Validation', () {
-    late Directory tempDir;
+    // Reassigned in setUp; the placeholder keeps the field non-`late`.
+    Directory tempDir = Directory.systemTemp;
 
     setUp(() async {
-      tempDir = await Directory.systemTemp.createTemp('metadata_test.');
-    });
-
-    tearDown(() async {
-      if (tempDir.existsSync()) {
-        await tempDir.delete(recursive: true);
-      }
+      tempDir = await createTempDir('metadata_test.');
     });
 
     test('fails if YAML metadata is invalid', () async {
diff --git a/tool/dart_skills_lint/test/relative_path_flag_test.dart b/tool/dart_skills_lint/test/relative_path_flag_test.dart
index b2a30dd..61d17d8 100644
--- a/tool/dart_skills_lint/test/relative_path_flag_test.dart
+++ b/tool/dart_skills_lint/test/relative_path_flag_test.dart
@@ -14,16 +14,11 @@ import 'test_utils.dart';
 
 void main() {
   group('Relative Path Flag Validation', () {
-    late Directory tempDir;
+    // Reassigned in setUp; the placeholder keeps the field non-`late`.
+    Directory tempDir = Directory.systemTemp;
 
     setUp(() async {
-      tempDir = await Directory.systemTemp.createTemp('relative_path_test.');
-    });
-
-    tearDown(() async {
-      if (tempDir.existsSync()) {
-        await tempDir.delete(recursive: true);
-      }
+      tempDir = await createTempDir('relative_path_test.');
     });
 
     test('validates links when relativePathsSeverity = warning', () async {
diff --git a/tool/dart_skills_lint/test/relative_paths_test.dart b/tool/dart_skills_lint/test/relative_paths_test.dart
index 8b74b45..4cb2482 100644
--- a/tool/dart_skills_lint/test/relative_paths_test.dart
+++ b/tool/dart_skills_lint/test/relative_paths_test.dart
@@ -14,16 +14,11 @@ import 'test_utils.dart';
 
 void main() {
   group('Relative Paths Validation', () {
-    late Directory tempDir;
+    // Reassigned in setUp; the placeholder keeps the field non-`late`.
+    Directory tempDir = Directory.systemTemp;
 
     setUp(() async {
-      tempDir = await Directory.systemTemp.createTemp('paths_test.');
-    });
-
-    tearDown(() async {
-      if (tempDir.existsSync()) {
-        await tempDir.delete(recursive: true);
-      }
+      tempDir = await createTempDir('paths_test.');
     });
 
     test('passes with valid relative file path (existing file)', () async {
diff --git a/tool/dart_skills_lint/test/skills_ignores_storage_test.dart b/tool/dart_skills_lint/test/skills_ignores_storage_test.dart
index 398f2b8..2b5ad77 100644
--- a/tool/dart_skills_lint/test/skills_ignores_storage_test.dart
+++ b/tool/dart_skills_lint/test/skills_ignores_storage_test.dart
@@ -8,17 +8,15 @@ import 'package:dart_skills_lint/src/models/skills_ignores.dart';
 import 'package:dart_skills_lint/src/skills_ignores_storage.dart';
 import 'package:test/test.dart';
 
+import 'test_utils.dart';
+
 void main() {
-  late Directory tempDir;
-  late SkillsIgnoresStorage storage;
+  final storage = SkillsIgnoresStorage();
+  // Reassigned in setUp; the placeholder keeps the field non-`late`.
+  Directory tempDir = Directory.systemTemp;
 
   setUp(() async {
-    tempDir = Directory.systemTemp.createTempSync('storage_test.');
-    storage = SkillsIgnoresStorage();
-  });
-
-  tearDown(() async {
-    await tempDir.delete(recursive: true);
+    tempDir = await createTempDir('storage_test.');
   });
 
   group('SkillsIgnoresStorage.load Integration', () {
diff --git a/tool/dart_skills_lint/test/test_utils.dart b/tool/dart_skills_lint/test/test_utils.dart
index afa45fd..1f3d831 100644
--- a/tool/dart_skills_lint/test/test_utils.dart
+++ b/tool/dart_skills_lint/test/test_utils.dart
@@ -5,6 +5,7 @@
 import 'dart:async';
 import 'dart:io';
 import 'package:path/path.dart' as p;
+import 'package:test/test.dart';
 
 String buildFrontmatter({
   String name = 'Skill-Name',
@@ -22,6 +23,19 @@ String buildFrontmatter({
   return sb.toString();
 }
 
+/// Creates a fresh temporary directory and registers automatic cleanup via
+/// [addTearDown]. Assign the result to a (non-`late`) variable in `setUp`; the
+/// directory is deleted after the test completes.
+Future<Directory> createTempDir(String prefix) async {
+  final Directory tempDir = await Directory.systemTemp.createTemp(prefix);
+  addTearDown(() async {
+    if (tempDir.existsSync()) {
+      await tempDir.delete(recursive: true);
+    }
+  });
+  return tempDir;
+}
+
 /// Creates a temporary directory for testing and automatically cleans it up.
 Future<void> withTempDir(FutureOr<void> Function(Directory tempDir) action) async {
   final Directory tempDir = await Directory.systemTemp.createTemp('api_test.');

From 003f11fb1f90587f5a46b92de719ec5e653e79f4 Mon Sep 17 00:00:00 2001
From: Reid Baker <reidbaker@google.com>
Date: Fri, 22 May 2026 01:15:23 -0400
Subject: [PATCH 2/3] Exclude avoid-late-keyword for tests instead of
 placeholder workaround

Address review feedback: rather than initializing tempDir fixtures to a
placeholder to satisfy avoid-late-keyword, exclude the rule for test/**
(as already done for prefer-match-file-name). `late` for fields assigned
in setUp is the idiomatic Dart test pattern. Reverts the createTempDir
helper and placeholder initializations; fixtures are plain `late` again.

The genuine, non-late fixes are kept: avoid-dynamic (Object? noSuchMethod)
and avoid-redundant-async (drop async from a sync setUp).
---
 tool/dart_skills_lint/analysis_options.yaml      |  6 +++++-
 .../test/absolute_paths_test.dart                | 11 ++++++++---
 .../test/cli_integration_test.dart               | 11 ++++++++---
 tool/dart_skills_lint/test/config_file_test.dart | 13 ++++++++-----
 tool/dart_skills_lint/test/custom_rule_test.dart | 13 ++++++++-----
 .../test/directory_structure_test.dart           | 13 ++++++++-----
 .../test/field_constraints_test.dart             | 11 ++++++++---
 tool/dart_skills_lint/test/fixer_test.dart       | 11 ++++++-----
 .../test/metadata_validation_test.dart           | 11 ++++++++---
 .../test/relative_path_flag_test.dart            | 11 ++++++++---
 .../test/relative_paths_test.dart                | 11 ++++++++---
 .../test/skills_ignores_storage_test.dart        | 16 +++++++++-------
 tool/dart_skills_lint/test/test_utils.dart       | 14 --------------
 13 files changed, 92 insertions(+), 60 deletions(-)

diff --git a/tool/dart_skills_lint/analysis_options.yaml b/tool/dart_skills_lint/analysis_options.yaml
index dcc52e6..195040e 100644
--- a/tool/dart_skills_lint/analysis_options.yaml
+++ b/tool/dart_skills_lint/analysis_options.yaml
@@ -295,7 +295,11 @@ dart_code_linter:
     - no-empty-block
     - avoid-redundant-async
     - avoid-passing-async-when-sync-expected
-    - avoid-late-keyword
+    # `late` for fields initialized in `setUp` is the idiomatic Dart test
+    # fixture pattern; enforce this rule on lib only.
+    - avoid-late-keyword:
+        exclude:
+          - test/**
     - prefer-named-record-fields
 
     # Clean up
diff --git a/tool/dart_skills_lint/test/absolute_paths_test.dart b/tool/dart_skills_lint/test/absolute_paths_test.dart
index d8ce750..46c3261 100644
--- a/tool/dart_skills_lint/test/absolute_paths_test.dart
+++ b/tool/dart_skills_lint/test/absolute_paths_test.dart
@@ -16,11 +16,16 @@ import 'test_utils.dart';
 
 void main() {
   group('Absolute Paths Validation', () {
-    // Reassigned in setUp; the placeholder keeps the field non-`late`.
-    Directory tempDir = Directory.systemTemp;
+    late Directory tempDir;
 
     setUp(() async {
-      tempDir = await createTempDir('absolute_path_test.');
+      tempDir = await Directory.systemTemp.createTemp('absolute_path_test.');
+    });
+
+    tearDown(() async {
+      if (tempDir.existsSync()) {
+        await tempDir.delete(recursive: true);
+      }
     });
 
     test('flags absolute path starting with / as warning by default', () async {
diff --git a/tool/dart_skills_lint/test/cli_integration_test.dart b/tool/dart_skills_lint/test/cli_integration_test.dart
index 5e51222..895cd28 100644
--- a/tool/dart_skills_lint/test/cli_integration_test.dart
+++ b/tool/dart_skills_lint/test/cli_integration_test.dart
@@ -19,11 +19,16 @@ import 'test_utils.dart';
 
 void main() {
   group('CLI Integration', () {
-    // Reassigned in setUp; the placeholder keeps the field non-`late`.
-    Directory tempDir = Directory.systemTemp;
+    late Directory tempDir;
 
     setUp(() async {
-      tempDir = await createTempDir('cli_test.');
+      tempDir = await Directory.systemTemp.createTemp('cli_test.');
+    });
+
+    tearDown(() async {
+      if (tempDir.existsSync()) {
+        await tempDir.delete(recursive: true);
+      }
     });
 
     test('de-duplicates baseline entries for multiple identical rule failures', () async {
diff --git a/tool/dart_skills_lint/test/config_file_test.dart b/tool/dart_skills_lint/test/config_file_test.dart
index 8e34412..dfd1d5c 100644
--- a/tool/dart_skills_lint/test/config_file_test.dart
+++ b/tool/dart_skills_lint/test/config_file_test.dart
@@ -9,15 +9,18 @@ import 'package:path/path.dart' as p;
 import 'package:test/test.dart';
 import 'package:test_process/test_process.dart';
 
-import 'test_utils.dart';
-
 void main() {
   group('Configuration File Integration', () {
-    // Reassigned in setUp; the placeholder keeps the field non-`late`.
-    Directory tempDir = Directory.systemTemp;
+    late Directory tempDir;
 
     setUp(() async {
-      tempDir = await createTempDir('config_test.');
+      tempDir = await Directory.systemTemp.createTemp('config_test.');
+    });
+
+    tearDown(() async {
+      if (tempDir.existsSync()) {
+        await tempDir.delete(recursive: true);
+      }
     });
 
     test('obeys disabled relative paths in config', () async {
diff --git a/tool/dart_skills_lint/test/custom_rule_test.dart b/tool/dart_skills_lint/test/custom_rule_test.dart
index c6b4822..48aa0d6 100644
--- a/tool/dart_skills_lint/test/custom_rule_test.dart
+++ b/tool/dart_skills_lint/test/custom_rule_test.dart
@@ -4,8 +4,6 @@ import 'package:dart_skills_lint/dart_skills_lint.dart';
 import 'package:logging/logging.dart';
 import 'package:test/test.dart';
 
-import 'test_utils.dart';
-
 class CustomRule extends SkillRule {
   @override
   final String name = 'custom-rule';
@@ -52,11 +50,16 @@ class MismatchRule extends SkillRule {
 
 void main() {
   group('Custom Rules', () {
-    // Reassigned in setUp; the placeholder keeps the field non-`late`.
-    Directory tempDir = Directory.systemTemp;
+    late Directory tempDir;
 
     setUp(() async {
-      tempDir = await createTempDir('custom_rule_test.');
+      tempDir = await Directory.systemTemp.createTemp('custom_rule_test.');
+    });
+
+    tearDown(() async {
+      if (tempDir.existsSync()) {
+        await tempDir.delete(recursive: true);
+      }
     });
 
     test('Validator runs custom rule', () async {
diff --git a/tool/dart_skills_lint/test/directory_structure_test.dart b/tool/dart_skills_lint/test/directory_structure_test.dart
index 6aa80f6..8d501a1 100644
--- a/tool/dart_skills_lint/test/directory_structure_test.dart
+++ b/tool/dart_skills_lint/test/directory_structure_test.dart
@@ -10,8 +10,6 @@ import 'package:dart_skills_lint/src/validator.dart';
 import 'package:path/path.dart' as p;
 import 'package:test/test.dart';
 
-import 'test_utils.dart';
-
 class MockInaccessibleFile implements File {
   MockInaccessibleFile(this._path);
   final String _path;
@@ -46,11 +44,16 @@ base class TestIOOverrides extends IOOverrides {
 
 void main() {
   group('Directory Structure Validation', () {
-    // Reassigned in setUp; the placeholder keeps the field non-`late`.
-    Directory tempDir = Directory.systemTemp;
+    late Directory tempDir;
 
     setUp(() async {
-      tempDir = await createTempDir('skill_test.');
+      tempDir = await Directory.systemTemp.createTemp('skill_test.');
+    });
+
+    tearDown(() async {
+      if (tempDir.existsSync()) {
+        await tempDir.delete(recursive: true);
+      }
     });
 
     test('fails if directory does not exist', () async {
diff --git a/tool/dart_skills_lint/test/field_constraints_test.dart b/tool/dart_skills_lint/test/field_constraints_test.dart
index 1eb2cfc..31c37f8 100644
--- a/tool/dart_skills_lint/test/field_constraints_test.dart
+++ b/tool/dart_skills_lint/test/field_constraints_test.dart
@@ -16,11 +16,16 @@ import 'test_utils.dart';
 
 void main() {
   group('Field Specific Constraints Validation', () {
-    // Reassigned in setUp; the placeholder keeps the field non-`late`.
-    Directory tempDir = Directory.systemTemp;
+    late Directory tempDir;
 
     setUp(() async {
-      tempDir = await createTempDir('fields_test.');
+      tempDir = await Directory.systemTemp.createTemp('fields_test.');
+    });
+
+    tearDown(() async {
+      if (tempDir.existsSync()) {
+        await tempDir.delete(recursive: true);
+      }
     });
 
     group('Skill Name', () {
diff --git a/tool/dart_skills_lint/test/fixer_test.dart b/tool/dart_skills_lint/test/fixer_test.dart
index 549bd37..75e173f 100644
--- a/tool/dart_skills_lint/test/fixer_test.dart
+++ b/tool/dart_skills_lint/test/fixer_test.dart
@@ -13,8 +13,6 @@ import 'package:dart_skills_lint/src/models/validation_error.dart';
 import 'package:path/path.dart' as p;
 import 'package:test/test.dart';
 
-import 'test_utils.dart';
-
 class RuleA extends SkillRule implements FixableRule {
   @override
   String get name => 'rule-a';
@@ -92,11 +90,14 @@ class RuleThrows extends SkillRule implements FixableRule {
 
 void main() {
   group('Fixer Sequential Execution', () {
-    // Reassigned in setUp; the placeholder keeps the field non-`late`.
-    Directory tempDir = Directory.systemTemp;
+    late Directory tempDir;
 
     setUp(() async {
-      tempDir = await createTempDir('fixer_test.');
+      tempDir = await Directory.systemTemp.createTemp('fixer_test.');
+    });
+
+    tearDown(() async {
+      await tempDir.delete(recursive: true);
     });
 
     test('applies fixes in order', () async {
diff --git a/tool/dart_skills_lint/test/metadata_validation_test.dart b/tool/dart_skills_lint/test/metadata_validation_test.dart
index a3c0ed1..cd807a7 100644
--- a/tool/dart_skills_lint/test/metadata_validation_test.dart
+++ b/tool/dart_skills_lint/test/metadata_validation_test.dart
@@ -13,11 +13,16 @@ import 'test_utils.dart';
 
 void main() {
   group('Metadata (YAML) Validation', () {
-    // Reassigned in setUp; the placeholder keeps the field non-`late`.
-    Directory tempDir = Directory.systemTemp;
+    late Directory tempDir;
 
     setUp(() async {
-      tempDir = await createTempDir('metadata_test.');
+      tempDir = await Directory.systemTemp.createTemp('metadata_test.');
+    });
+
+    tearDown(() async {
+      if (tempDir.existsSync()) {
+        await tempDir.delete(recursive: true);
+      }
     });
 
     test('fails if YAML metadata is invalid', () async {
diff --git a/tool/dart_skills_lint/test/relative_path_flag_test.dart b/tool/dart_skills_lint/test/relative_path_flag_test.dart
index 61d17d8..b2a30dd 100644
--- a/tool/dart_skills_lint/test/relative_path_flag_test.dart
+++ b/tool/dart_skills_lint/test/relative_path_flag_test.dart
@@ -14,11 +14,16 @@ import 'test_utils.dart';
 
 void main() {
   group('Relative Path Flag Validation', () {
-    // Reassigned in setUp; the placeholder keeps the field non-`late`.
-    Directory tempDir = Directory.systemTemp;
+    late Directory tempDir;
 
     setUp(() async {
-      tempDir = await createTempDir('relative_path_test.');
+      tempDir = await Directory.systemTemp.createTemp('relative_path_test.');
+    });
+
+    tearDown(() async {
+      if (tempDir.existsSync()) {
+        await tempDir.delete(recursive: true);
+      }
     });
 
     test('validates links when relativePathsSeverity = warning', () async {
diff --git a/tool/dart_skills_lint/test/relative_paths_test.dart b/tool/dart_skills_lint/test/relative_paths_test.dart
index 4cb2482..8b74b45 100644
--- a/tool/dart_skills_lint/test/relative_paths_test.dart
+++ b/tool/dart_skills_lint/test/relative_paths_test.dart
@@ -14,11 +14,16 @@ import 'test_utils.dart';
 
 void main() {
   group('Relative Paths Validation', () {
-    // Reassigned in setUp; the placeholder keeps the field non-`late`.
-    Directory tempDir = Directory.systemTemp;
+    late Directory tempDir;
 
     setUp(() async {
-      tempDir = await createTempDir('paths_test.');
+      tempDir = await Directory.systemTemp.createTemp('paths_test.');
+    });
+
+    tearDown(() async {
+      if (tempDir.existsSync()) {
+        await tempDir.delete(recursive: true);
+      }
     });
 
     test('passes with valid relative file path (existing file)', () async {
diff --git a/tool/dart_skills_lint/test/skills_ignores_storage_test.dart b/tool/dart_skills_lint/test/skills_ignores_storage_test.dart
index 2b5ad77..99c10f3 100644
--- a/tool/dart_skills_lint/test/skills_ignores_storage_test.dart
+++ b/tool/dart_skills_lint/test/skills_ignores_storage_test.dart
@@ -8,15 +8,17 @@ import 'package:dart_skills_lint/src/models/skills_ignores.dart';
 import 'package:dart_skills_lint/src/skills_ignores_storage.dart';
 import 'package:test/test.dart';
 
-import 'test_utils.dart';
-
 void main() {
-  final storage = SkillsIgnoresStorage();
-  // Reassigned in setUp; the placeholder keeps the field non-`late`.
-  Directory tempDir = Directory.systemTemp;
+  late Directory tempDir;
+  late SkillsIgnoresStorage storage;
+
+  setUp(() {
+    tempDir = Directory.systemTemp.createTempSync('storage_test.');
+    storage = SkillsIgnoresStorage();
+  });
 
-  setUp(() async {
-    tempDir = await createTempDir('storage_test.');
+  tearDown(() async {
+    await tempDir.delete(recursive: true);
   });
 
   group('SkillsIgnoresStorage.load Integration', () {
diff --git a/tool/dart_skills_lint/test/test_utils.dart b/tool/dart_skills_lint/test/test_utils.dart
index 1f3d831..afa45fd 100644
--- a/tool/dart_skills_lint/test/test_utils.dart
+++ b/tool/dart_skills_lint/test/test_utils.dart
@@ -5,7 +5,6 @@
 import 'dart:async';
 import 'dart:io';
 import 'package:path/path.dart' as p;
-import 'package:test/test.dart';
 
 String buildFrontmatter({
   String name = 'Skill-Name',
@@ -23,19 +22,6 @@ String buildFrontmatter({
   return sb.toString();
 }
 
-/// Creates a fresh temporary directory and registers automatic cleanup via
-/// [addTearDown]. Assign the result to a (non-`late`) variable in `setUp`; the
-/// directory is deleted after the test completes.
-Future<Directory> createTempDir(String prefix) async {
-  final Directory tempDir = await Directory.systemTemp.createTemp(prefix);
-  addTearDown(() async {
-    if (tempDir.existsSync()) {
-      await tempDir.delete(recursive: true);
-    }
-  });
-  return tempDir;
-}
-
 /// Creates a temporary directory for testing and automatically cleans it up.
 Future<void> withTempDir(FutureOr<void> Function(Directory tempDir) action) async {
   final Directory tempDir = await Directory.systemTemp.createTemp('api_test.');

From 3efac9072f2757799ff7934337a36b469f40f4eb Mon Sep 17 00:00:00 2001
From: Reid Baker <1063596+reidbaker@users.noreply.github.com>
Date: Fri, 22 May 2026 09:50:01 -0400
Subject: [PATCH 3/3] Apply suggestion from @reidbaker

---
 tool/dart_skills_lint/analysis_options.yaml | 14 +++-----------
 1 file changed, 3 insertions(+), 11 deletions(-)

diff --git a/tool/dart_skills_lint/analysis_options.yaml b/tool/dart_skills_lint/analysis_options.yaml
index 195040e..7128ea6 100644
--- a/tool/dart_skills_lint/analysis_options.yaml
+++ b/tool/dart_skills_lint/analysis_options.yaml
@@ -15,17 +15,9 @@ analyzer:
     strict-casts: true
     strict-inference: true
     strict-raw-types: true
-  # NOTE: dart_code_linter is intentionally NOT registered as an analyzer
-  # `plugin` here. When it was, `dart analyze` loaded the plugin in a separate
-  # isolate that re-emitted the `dart_code_linter:` rules (below) as diagnostics
-  # over the plugin protocol, covering all non-excluded files (including test/).
-  # Delivery of those diagnostics to the `dart analyze` CLI is asynchronous and
-  # racy, so on slower runners (Windows CI) they intermittently appeared, and
-  # `--fatal-infos` turned them fatal — a flaky, platform-specific failure
-  # (https://github.com/flutter/skills/issues/144). The dedicated
-  # `dart run dart_code_linter:metrics analyze lib test` CI step reads the
-  # `dart_code_linter:` config below and enforces those rules deterministically,
-  # so the plugin registration is unnecessary.
+  # dart_code_linter is intentionally NOT registered as an analyzer
+  # `plugin` here. When it was, `dart analyze` had racy false positives. 
+  # See https://github.com/flutter/skills/issues/144
   errors:
     # allow deprecated members (we do this because otherwise we have to annotate
     # every member in every test, assert, etc, when we or the Dart SDK deprecates