Add trailing whitespace validator

tool/dart_skills_lint/.agents/skills/add-dart-lint-validation-rule/SKILL.md

@@ -11,114 +11,116 @@ Use this skill when you need to add a new validation rule to the `dart_skills_li
 
 ## 🛠️ Step-by-Step Implementation
 
-### 1. Define the Rule in `lib/src/rules.dart`
-
-To create a new rule, add a top-level `CheckType` instance.
+### 1. Create the Rule Class
+Create a new file in `lib/src/rules/` extending `SkillRule`.
 
 ```dart
-// lib/src/rules.dart
-
-/// Template instance for checking if the description has a trailing period.
-final descriptionTrailingPeriodCheck = CheckType(
-  name: 'description-trailing-period',
-  defaultSeverity: AnalysisSeverity.error, // or warning/disabled
-);
-```
+// lib/src/rules/my_new_rule.dart
 
-### 2. Expose the CLI Flag in `lib/src/entry_point.dart`
+import '../models/analysis_severity.dart';
+import '../models/skill_context.dart';
+import '../models/skill_rule.dart';
+import '../models/validation_error.dart';
 
-Modify `runApp` to include the toggleable flag for your new rule.
-
-#### 📋 Register Parser Option
-Add `.addFlag` in `runApp` (around line 60-90):
-
-```dart
-// lib/src/entry_point.dart
+class MyNewRule extends SkillRule {
+  MyNewRule({super.severity});
 
-parser
-  ..addFlag(descriptionTrailingPeriodCheck.name,
-      negatable: true,
-      defaultsTo: true,
-      help: 'Check if the description ends with a period.');
-```
-
-#### 🎚️ Resolve Flag Logic or Override Severities
-Find where severities are evaluated (around line 140-170) and bind your flag state:
-
-```dart
-if (results.wasParsed(descriptionTrailingPeriodCheck.name)) {
-  descriptionTrailingPeriodCheck.severity = (results[descriptionTrailingPeriodCheck.name] as bool)
-      ? descriptionTrailingPeriodCheck.defaultSeverity
-      : AnalysisSeverity.disabled;
+  @override
+  Future<List<ValidationError>> validate(SkillContext context) async {
+    final errors = <ValidationError>[];
+    // Add validation logic here using context.rawContent or context.directory
+    return errors;
+  }
 }
 ```
 
-Add your rule to the `checkTypes` set if you want it loaded by default configuration overrides.
+### 2. Register the Rule in `lib/src/rule_registry.dart`
 
-### 3. Implement Validation in `lib/src/validator.dart`
-
-Write the specific logic inside `Validator` checking the schema.
+Add a new `CheckType` instance to `RuleRegistry.allChecks` list. This automatically exposes it as a CLI flag.
 
 ```dart
-// lib/src/validator.dart
-
-void _validateDescriptionPeriod(String description, List<ValidationError> validationErrors) {
-  if (description.isNotEmpty && !description.endsWith('.')) {
-    validationErrors.add(ValidationError(
-      ruleId: _getRule(descriptionTrailingPeriodCheck).name,
-      file: _skillFileName,
-      message: 'Description must end with a period.',
-      severity: _getRule(descriptionTrailingPeriodCheck).severity,
-    ));
-  }
-}
+// lib/src/rule_registry.dart in allChecks list
+
+  const CheckType(
+    name: MyNewRule.ruleName,
+    defaultSeverity: MyNewRule.defaultSeverity,
+    help: 'Description of what the rule does for CLI help.',
+  ),
 ```
 
-Invoke your sub-routine inside `_parseMetadataFields`:
+Then, add a case to `RuleRegistry.createRule` to instantiate your rule:
 
 ```dart
-final description = yaml[_descriptionField]?.toString() ?? '';
-if (description.isNotEmpty) {
-  _validateDescriptionPeriod(description, validationErrors);
-}
+// lib/src/rule_registry.dart in createRule method
+
+  static SkillRule? createRule(String name, AnalysisSeverity severity) {
+    switch (name) {
+      // ... other rules
+      case MyNewRule.ruleName:
+        return MyNewRule(severity: severity);
+      default:
+        return null;
+    }
+  }
 ```
 
+### 3. Handle Disabled by Default Rules (If applicable)
+If the rule is disabled by default (`defaultSeverity: AnalysisSeverity.disabled`), passing the flag `--check-my-new-rule` will automatically enable it with `AnalysisSeverity.error` severity (handled in `entry_point.dart`).
+
 ---
 
 ## 🧪 Testing the New Rule
 
 You must write automated tests verifying your rule triggers when it should and skips when it shouldn't.
 
-### Creating a Test Suite Case
-Add matching suite files in `test/` (e.g., `test/field_constraints_test.dart` or `test/metadata_validation_test.dart`).
+### Preferred Approach: In-Memory Unit Tests
+Instead of writing files to disk, test the rule directly using a mock `SkillContext`. This is faster and avoids I/O dependencies.
 
 ```dart
-// test/field_constraints_test.dart
-
-test('triggers error when description does not end with period', () async {
-  final tempDir = createTempSkillDir(
-    name: 'test-skill',
-    description: 'This description does not end with a period',
-  );
-
-  final validator = Validator(rules: {descriptionTrailingPeriodCheck});
-  final result = await validator.validate(tempDir);
-
-  expect(result.validationErrors.any((e) => e.ruleId == 'description-trailing-period'), isTrue);
-});
-test('skips error when description ends with period', () async {
-  final tempDir = createTempSkillDir(
-    name: 'test-skill',
-    description: 'This description ends with a period.',
-  );
-
-  final validator = Validator(rules: {descriptionTrailingPeriodCheck});
-  final result = await validator.validate(tempDir);
-
-  expect(result.validationErrors.any((e) => e.ruleId == 'description-trailing-period'), isFalse);
-});
+// test/my_new_rule_test.dart
+
+import 'dart:io';
+import 'package:dart_skills_lint/src/models/analysis_severity.dart';
+import 'package:dart_skills_lint/src/models/skill_context.dart';
+import 'package:dart_skills_lint/src/models/validation_error.dart';
+import 'package:dart_skills_lint/src/rules/my_new_rule.dart';
+import 'package:test/test.dart';
+
+void main() {
+  group('MyNewRule', () {
+    test('flags invalid content', () async {
+      final rule = MyNewRule(severity: AnalysisSeverity.warning);
+      final context = SkillContext(
+        directory: Directory('dummy'),
+        rawContent: 'Invalid content',
+      );
+
+      final List<ValidationError> errors = await rule.validate(context);
+
+      expect(errors, isNotEmpty);
+      expect(errors.first.message, contains('Expected error message'));
+    });
+
+    test('passes valid content', () async {
+      final rule = MyNewRule(severity: AnalysisSeverity.warning);
+      final context = SkillContext(
+        directory: Directory('dummy'),
+        rawContent: 'Valid content',
+      );
+
+      final List<ValidationError> errors = await rule.validate(context);
+
+      expect(errors, isEmpty);
+    });
+  });
+}
 ```
 
+### Integration Tests
+If the rule interacts with CLI flags or configuration files, add a test in `test/cli_integration_test.dart` using `TestProcess`.
+> [!IMPORTANT]
+> When writing integration tests that use config files and `TestProcess`, ensure that paths in the config file and paths passed to the CLI match in style (both relative or both absolute) to avoid issues with path matching in `entry_point.dart`.
+
 ---
 
 ## 📚 Documentation Updates
@@ -127,20 +129,18 @@ When a new rule is introduced, verify that you synchronize sibling markdown file
 
 1.  **`README.md`:**
     *   Add your flag under the **Usage** and **Flags** sections so users know it exists.
-    *   Add descriptive lines under **Specification Validation**.
 2.  **`documentation/knowledge/SPECIFICATION.md`:**
-    *   If the rule implements standard specifications traits, add constraints parameters under Section 5.1 (Validation parameters).
+    *   Document the formal constraint in the specification if it defines a standard for skill files.
 
 ---
 
 ## 🚦 Checklist Before Submitting PR
 
-- [ ] Rule defined in `rules.dart`.
-- [ ] Flag registered in `entry_point.dart`.
-- [ ] Logic implemented in `validator.dart`.
-- [ ] Toggle logic tests added in `test/`.
+- [ ] Rule class created in `lib/src/rules/`.
+- [ ] Rule registered in `lib/src/rule_registry.dart`.
+- [ ] Unit tests added in `test/` using in-memory `SkillContext`.
 - [ ] Usage listed in `README.md`.
-- [ ] Schema documented in `documentation/knowledge/SPECIFICATION.md`.
-- [ ] Run `dart analyze` to ensure no issues.
-- [ ] Run `dart test` to ensure tests passing.
+- [ ] Schema documented in `documentation/knowledge/SPECIFICATION.md` (if applicable).
 - [ ] Run `dart format .` to format code.
+- [ ] Run `dart analyze --fatal-infos` to ensure no issues.
+- [ ] Run `dart test` to ensure tests passing.

tool/dart_skills_lint/.agents/skills/dart-best-practices/SKILL.md

@@ -47,6 +47,8 @@ or identifiers that cannot be broken.
 
 ## Related Skills
 
-- **[`dart-modern-features`](../dart-modern-features/SKILL.md)**: For idiomatic
+- **[dart-modern-features]**: For idiomatic
   usage of modern Dart features like Pattern Matching (useful for deep JSON
   extraction), Records, and Switch Expressions.
+
+[dart-modern-features]: https://github.com/kevmoo/dash_skills/blob/main/.agent/skills/dart-modern-features/SKILL.md

tool/dart_skills_lint/.agents/skills/dart-cli-app-best-practices/SKILL.md

@@ -93,6 +93,15 @@ Future<void> main(List<String> arguments) async {
 }
 ```
 
+### Cross-Platform Compatibility (Windows Support)
+When writing CLI applications and tests, ensure compatibility with Windows:
+- **Paths**: Never hardcode path separators like `/`. Use `package:path`'s
+  `p.join` or `p.normalize` to construct paths portably.
+- **File Permissions**: When testing file permission errors, remember that
+  `chmod` is not available on Windows. Use `icacls` on Windows or appropriate
+  mock libraries. Never skip tests on Windows simply because of permission
+  commands if a Windows equivalent exists.
+
 ## 3. Recommended Packages
 
 Use these community-standard packages owned by the [Dart team](https://dart.dev)

tool/dart_skills_lint/.agents/skills/dart-matcher-best-practices/SKILL.md

@@ -16,7 +16,7 @@ Use this skill when:
 
 ## Core Matchers
 
-### 1. Collections (`hasLength`, `contains`, `isEmpty`)
+### 1. Collections (`hasLength`, `contains`, `isEmpty`, `unorderedEquals`, `containsPair`)
 
 - **`hasLength(n)`**:
   - Prefer `expect(list, hasLength(n))` over `expect(list.length, n)`.
@@ -28,9 +28,16 @@ Use this skill when:
 
 - **`contains(item)`**:
   - Verify existence without manual iteration.
+  - Prefer over `expect(list.contains(item), true)`.
 
 - **`unorderedEquals(items)`**:
   - Verify contents regardless of order.
+  - Prefer over `expect(list, containsAll(items))`.
+
+- **`containsPair(key, value)`**:
+  - Verify a map contains a specific key-value pair.
+  - Prefer over checking `expect(map[key], value)` or 
+    `expect(map.containsKey(key), true)`.
 
 ### 2. Type Checks (`isA<T>` and `TypeMatcher<T>`)
 
@@ -99,8 +106,11 @@ expect(sideEffectState, equals('done')); // Race condition!
 
 ## Related Skills
 
-- **[`dart-test-fundamentals`](../dart-test-fundamentals/SKILL.md)**: Core
+- **[dart-test-fundamentals]**: Core
   concepts for structuring tests, lifecycles, and configuration.
-- **[`dart-checks-migration`](../dart-checks-migration/SKILL.md)**: Use this
+- **[dart-checks-migration]**: Use this
   skill if you are migrating tests from `package:matcher` to modern
   `package:checks`.
+
+[dart-test-fundamentals]: https://github.com/kevmoo/dash_skills/blob/main/.agent/skills/dart-test-fundamentals/SKILL.md
+[dart-checks-migration]: https://github.com/kevmoo/dash_skills/blob/main/.agent/skills/dart-checks-migration/SKILL.md

tool/dart_skills_lint/.agents/skills/dart-modern-features/SKILL.md

@@ -236,6 +236,8 @@ LogLevel currentLevel = .info;
 
 ## Related Skills
 
-- **[`dart-best-practices`](../dart-best-practices/SKILL.md)**: General code
+- **[dart-best-practices]**: General code
   style and foundational Dart idioms that predate or complement the modern
   syntax features.
+
+[dart-best-practices]: https://github.com/kevmoo/dash_skills/blob/main/.agent/skills/dart-best-practices/SKILL.md

tool/dart_skills_lint/.agents/skills/dart-test-fundamentals/SKILL.md

@@ -117,8 +117,11 @@ timeouts:
 `dart-test-fundamentals` is the core skill for structuring and configuring
 tests. For writing assertions within those tests, refer to:
 
-- **[`dart-matcher-best-practices`](../dart-matcher-best-practices/SKILL.md)**:
+- **[dart-matcher-best-practices]**:
   Use this if the project sticks with the traditional
   `package:matcher` (`expect` calls).
-- **[`dart-checks-migration`](../dart-checks-migration/SKILL.md)**: Use this
+- **[dart-checks-migration]**: Use this
   if the project is migrating to the modern `package:checks` (`check` calls).
+
+[dart-matcher-best-practices]: https://github.com/kevmoo/dash_skills/blob/main/.agent/skills/dart-matcher-best-practices/SKILL.md
+[dart-checks-migration]: https://github.com/kevmoo/dash_skills/blob/main/.agent/skills/dart-checks-migration/SKILL.md

tool/dart_skills_lint/.agents/skills/flutter_skills_ignore.json

@@ -1,3 +1,3 @@
 {
   "skills": {}
-}
+}

tool/dart_skills_lint/.agents/skills/ignore.json

@@ -1,14 +1,14 @@
 {
   "skills": {
-    "dart-matcher-best-practices": [
+    "dart-modern-features": [
       {
-        "rule_id": "check-relative-paths",
+        "rule_id": "check-trailing-whitespace",
         "file_name": "SKILL.md"
       }
     ],
-    "dart-test-fundamentals": [
+    "dart-matcher-best-practices": [
       {
-        "rule_id": "check-relative-paths",
+        "rule_id": "check-trailing-whitespace",
         "file_name": "SKILL.md"
       }
     ]

tool/dart_skills_lint/README.md

@@ -73,6 +73,7 @@ If no directory is specified, it automatically checks `.claude/skills` and `.age
 - `-w`, `--print-warnings`: Enable printing of warning messages.
 - `--fast-fail`: Halt execution immediately on the error.
 - `--ignore-config`: Ignore the YAML configuration file entirely.
+- `--[no-]check-trailing-whitespace`: Enable/disable checking for trailing whitespace. (Disabled by default).
 
 ### 2. As a Command Line Tool with a YAML Configuration File
 You can configure the linter using a configuration file (defaulting to `dart_skills_lint.yaml` in the current directory).
@@ -190,6 +191,9 @@ The linter checks against the criteria defined in `documentation/knowledge/SPECI
 - **Description (`description`)**: Max 1024 characters.
 - **Compatibility (`compatibility`)**: Max 500 characters.
 
+### 4. Content Constraints
+- **Trailing Whitespace**: Lines in `SKILL.md` should not have trailing whitespace. Exactly 2 spaces at the end of a line are allowed to support Markdown hard line breaks, per the [CommonMark Spec](https://spec.commonmark.org/0.30/#hard-line-breaks).
+
 ## Contributing
 
 Contributions are welcome! Please ensure that any PRs pass the linter themselves and align with the `documentation/knowledge/SPECIFICATION.md`.

tool/dart_skills_lint/dart_skills_lint.yaml

@@ -4,6 +4,7 @@ dart_skills_lint:
     check-absolute-paths: error
   directories:
     - path: ".agents/skills"
+      check-trailing-whitespace: error
       ignore_file: ".agents/skills/ignore.json"
     - path: "../../skills"
       ignore_file: ".agents/skills/flutter_skills_ignore.json"

tool/dart_skills_lint/documentation/knowledge/SPECIFICATION.md

@@ -61,6 +61,9 @@ Validation ensures that a skill directory and its `SKILL.md` file adhere to the
 - **Compatibility (`compatibility`)**:
   - Length: Maximum 500 characters.
 
+#### 4.1.4 Content Constraints
+- **Trailing Whitespace**: Lines in `SKILL.md` should not have trailing whitespace. Exactly 2 spaces at the end of a line are allowed to support Markdown hard line breaks, per the [CommonMark Spec](https://spec.commonmark.org/0.30/#hard-line-breaks).
+
 ### 5.2 Scripts & Tools
 - Scripts in the `scripts/` directory should be self-documenting and provide clear error messages.