Flutter Code Quality Checker

🛡️ A comprehensive Dart/Flutter code quality analyzer with 48 rules across 10 categories — get a coding standard score, clickable inline issues, and fix suggestions.

✨ Features at a Glance

🔍 10 Powerful Analyzers

Total: 48 rules — all configurable, all with fix suggestions!

📊 Coding Standard Score (0-100)

Get a quality score with color-coded grades:

The score uses weighted severity penalties: Errors (-5), Warnings (-3), Info (-1), Hints (-0.5). Project-wide scans scale logarithmically so large projects aren't unfairly penalized.

🖥️ Beautiful Bottom Panel UI

• Score Gauge — Animated circular progress with color-coded grade
• Issue Cards — Real-time counts of Errors, Warnings, Info, and Hints
• Clickable Issues — Click any issue to jump directly to the problematic line
• Filters & Sorting — Filter by category/severity; sort by file, line, or severity
• Theme Support — Adapts to VS Code dark and light themes

🎯 Flexible Scope

• Check Current File — Analyze just the active Dart file
• Check Entire Project — Scan all Dart files in your workspace

⚡ Smart Exclusions

Automatically skips generated and non-production files:

• *.g.dart, *.freezed.dart, *.mocks.dart
• Test files (configurable)
• Build directories and .dart_tool

🚀 Getting Started

Installation

1. Open VS Code
2. Go to Extensions (Ctrl+Shift+X / Cmd+Shift+X)
3. Search for "Flutter Code Quality Checker"
4. Click Install

Usage

1. Open a Flutter/Dart project
2. Open Command Palette (Ctrl+Shift+P / Cmd+Shift+P)
3. Type "Flutter Quality: Analyze Code Quality"
4. Select "Check Current File" or "Check Entire Project"
5. View results in the Flutter Quality panel at the bottom

You can also:

• Click the shield icon in the editor title bar
• Check the status bar for your last score
• Use keyboard shortcut to re-analyze

📋 Rules Reference

🖨️ Print Statements

// ❌ Bad
print('debug value: $value');
debugPrint('something');

// ✅ Good
if (kDebugMode) {
  debugPrint('debug value: $value');
}

🏗️ Missing Const

// ❌ Bad — only flagged when arguments are true compile-time literals
Text('Hello World')
SizedBox(height: 16)
EdgeInsets.all(8.0)

// ✅ Good
const Text('Hello World')
const SizedBox(height: 16)
const EdgeInsets.all(8.0)

// ✅ NOT flagged — runtime values are correctly skipped
SizedBox(height: SizeConfig.h * AppSpacing.s36)
EdgeInsets.only(bottom: AppSpacing.s16)

🧱 BLoC Issues

// ❌ Bad — Side effect in BlocBuilder
BlocBuilder<MyBloc, MyState>(
  builder: (context, state) {
    Navigator.of(context).pop(); // Side effect!
    return Container();
  },
);

// ✅ Good — Use BlocListener for side effects
BlocListener<MyBloc, MyState>(
  listener: (context, state) {
    Navigator.of(context).pop();
  },
  child: BlocBuilder<MyBloc, MyState>(
    builder: (context, state) => Container(),
  ),
);

🔄 Unnecessary Rebuilds

// ❌ Bad — Controller created in build()
Widget build(BuildContext context) {
  final controller = TextEditingController(); // Recreated every build!
  return TextField(controller: controller);
}

// ✅ Good
late final _controller = TextEditingController();
Widget build(BuildContext context) {
  return TextField(controller: _controller);
}

🔒 Null Safety

// ❌ Bad — Force unwrap risks runtime crash
final name = user!.name;
final first = list.first!;

// ✅ Good
final name = user?.name ?? 'Unknown';
final first = list.firstOrNull;

⏳ Async Operations

// ❌ Bad — Using context after async gap without mounted check
Future<void> _onSubmit() async {
  await repository.save(data);
  Navigator.of(context).pop(); // Widget might be disposed!
}

// ✅ Good
Future<void> _onSubmit() async {
  await repository.save(data);
  if (!mounted) return;
  Navigator.of(context).pop();
}

🌐 API Usage

// ❌ Bad — API call without error handling
final response = await http.get(Uri.parse(url));

// ✅ Good
try {
  final response = await http.get(Uri.parse(url));
} catch (e) {
  // Handle error gracefully
}

🏛️ Separation of Concerns

// ❌ Bad — API call directly in widget
class MyWidget extends StatelessWidget {
  Widget build(BuildContext context) {
    final response = await http.get(url); // Direct API call!
    return Text(response.body);
  }
}

// ✅ Good — Use Repository + BLoC/Provider pattern
class MyWidget extends StatelessWidget {
  Widget build(BuildContext context) {
    return BlocBuilder<MyBloc, MyState>(
      builder: (context, state) => Text(state.data),
    );
  }
}

🧹 Clean Code

// ❌ Bad — Commented-out code and URLs
// final data = await fetchData();
// final result = transform(data);
// https://api.old-server.com/v1/users

// ✅ Good — Use version control, not comments
// Use proper configuration for URLs

⚙️ Configuration

Open Settings (Ctrl+,) and search for "Flutter Quality Checker":

📈 Scoring System

For project-wide scans, deductions scale logarithmically with file count — so a few issues in a big project don't tank your score.

📋 Complete Rules, Severity & Scoring Matrix

Each rule belongs to one of the 10 Categories and carries a specific Severity, which translates directly into score deductions:

🤝 Contributing

Contributions are welcome! Please feel free to submit issues and pull requests.

📄 License

This project is licensed under the MIT License — see the LICENSE file for details.

Made with ❤️ for the Flutter community by Vishal Gole