A comprehensive, enterprise-grade linting package for Flutter projects that ensures code quality, performance, security, and accessibility compliance.

• avoid_empty_catch_blocks - Prevents silent error swallowing
• avoid_long_methods - Enforces method length limits (default: 50 lines)
• avoid_magic_numbers - Requires constants for hardcoded numbers
• avoid_nested_conditionals - Limits conditional nesting depth
• prefer_early_return - Encourages guard clauses
• prefer_single_widget_per_file - Promotes better organization
• prefer_trailing_commas - Ensures consistent formatting

• prefer_slivers_over_columns - Optimizes scrolling performance for long lists
• avoid_widget_rebuilds - Detects unnecessary widget rebuilds
• prefer_stateless_widgets - Suggests StatelessWidget when appropriate
• avoid_build_context_across_async - Prevents common async context errors

• enforce_layer_dependencies - Validates clean architecture layer dependencies

• avoid_hardcoded_secrets - Detects API keys, passwords, and other secrets

• Comprehensive Analysis - Multi-dimensional code quality assessment
• Performance Profiling - Widget tree optimization and memory leak detection
• Security Scanning - Vulnerability assessment and secret detection
• Accessibility Compliance - WCAG guidelines validation
• Interactive Reports - HTML/JSON/Markdown report generation

Add this to your package's pubspec.yaml:

dev_dependencies:
  custom_lint: ^0.6.4
  flutter_quality_lints: ^0.9.1

Create or update your analysis_options.yaml:

analyzer:
  plugins:
    - custom_lint

custom_lint:
  rules:
    # Recommended preset (10 rules)
    - avoid_empty_catch_blocks
    - avoid_magic_numbers
    - prefer_early_return
    - prefer_trailing_commas
    - avoid_widget_rebuilds
    - prefer_stateless_widgets
    - avoid_build_context_across_async
    - avoid_hardcoded_secrets
    - enforce_layer_dependencies
    - prefer_slivers_over_columns

Choose from predefined rule sets:

// In your custom_lint.yaml or analysis_options.yaml
import 'package:flutter_quality_lints/flutter_quality_lints.dart';

// Available presets:
FlutterQualityLints.basicRules        // 5 essential rules
FlutterQualityLints.recommendedRules  // 10 production-ready rules
FlutterQualityLints.strictRules       // All 13 rules
FlutterQualityLints.performanceRules  // 4 performance-focused rules
FlutterQualityLints.securityRules     // 1 security rule

flutter_quality_lints:
  # Core Rules Configuration
  avoid_long_methods:
    max_lines: 50
    exclude_getters: true
    exclude_constructors: true
  
  avoid_magic_numbers:
    allowed_numbers: [0, 1, -1, 2, 10, 100, 1000]
    ignore_in_tests: true
  
  # Performance Rules Configuration
  prefer_slivers_over_columns:
    max_children: 10
    check_scrollable_nesting: true
  
  avoid_widget_rebuilds:
    check_const_usage: true
    check_inline_functions: true
  
  # Architecture Rules Configuration
  enforce_layer_dependencies:
    layers:
      presentation: ["lib/presentation/", "lib/ui/", "lib/pages/"]
      domain: ["lib/domain/", "lib/entities/", "lib/usecases/"]
      data: ["lib/data/", "lib/datasources/", "lib/models/"]
    
    dependency_rules:
      presentation: ["domain"]  # Can only depend on domain
      domain: []                # Pure - no dependencies
      data: ["domain"]          # Can only depend on domain
  
  # Security Rules Configuration
  avoid_hardcoded_secrets:
    min_secret_length: 10
    ignore_test_files: true
    check_patterns:
      - api_keys
      - jwt_tokens
      - oauth_tokens

The Flutter Quality Lints CLI provides advanced analysis capabilities:

# Add to pubspec.yaml
dependencies:
  flutter_quality_lints: ^0.9.1

# Make CLI executable
chmod +x bin/flutter_quality_lints.dart

dart bin/flutter_quality_lints.dart analyze [target_directory]

# Example output:
# Running Flutter Quality Analysis on: lib
# Analysis Results:
# Files analyzed: 25
# Issues found: 12
# Critical: 2
# Warning: 7
# Info: 3
# Quality Score: 9.5/10.0

dart bin/flutter_quality_lints.dart performance [target_directory]

# Features:
# Widget Tree Complexity Analysis
# Memory Leak Detection
# Unnecessary Rebuild Detection
# Performance Score Calculation

dart bin/flutter_quality_lints.dart optimize [target_directory]

# Provides:
# Widget Optimizations
# State Management Improvements
# Build Context Safety Recommendations

dart bin/flutter_quality_lints.dart security [target_directory]

# Detects:
# Hardcoded Secrets (API keys, passwords)
# Input Validation Issues
# Insecure Network Connections

dart bin/flutter_quality_lints.dart accessibility [target_directory]

# Validates:
# WCAG AA Compliance
# Semantic Labels
# Color Contrast Ratios
# Focus Management

dart bin/flutter_quality_lints.dart report [html|json|markdown]

# Generates:
# Comprehensive Quality Reports
# Trend Analysis Charts
# Interactive Navigation
# Export to PDF (HTML format)

# Preview fixes without applying them
dart bin/flutter_quality_lints.dart fix [target_directory] --dry-run

# Apply automatic fixes
dart bin/flutter_quality_lints.dart fix [target_directory]

# Auto-fixes include:
# - Add const to widget constructors
# - Add trailing commas
# - Convert to StatelessWidget
# - Add mounted checks after async
# - Simplify nested conditionals
# - Extract magic numbers to constants

// Bad
Container(width: 250, height: 150);

// Good
class Constants {
  static const double cardWidth = 250;
  static const double cardHeight = 150;
}
Container(width: Constants.cardWidth, height: Constants.cardHeight);

// Bad
String processUser(User? user) {
  if (user != null) {
    if (user.isActive) {
      return user.name;
    } else {
      return 'Inactive user';
    }
  } else {
    return 'No user';
  }
}

// Good
String processUser(User? user) {
  if (user == null) return 'No user';
  if (!user.isActive) return 'Inactive user';
  return user.name;
}

// Bad - Performance issue with many children
Column(
  children: List.generate(1000, (index) => Text('Item $index')),
)

// Good - Efficient scrolling
CustomScrollView(
  slivers: [
    SliverList(
      delegate: SliverChildBuilderDelegate(
        (context, index) => Text('Item $index'),
        childCount: 1000,
      ),
    ),
  ],
)

// Bad - Context used after async operation
Future<void> deleteItem() async {
  await apiService.deleteItem();
  Navigator.of(context).pop(); // Dangerous!
}

// Good - Check if mounted
Future<void> deleteItem() async {
  await apiService.deleteItem();
  if (mounted) {
    Navigator.of(context).pop();
  }
}

// Bad
const String apiKey = 'sk_live_abcd1234567890';

// Good
final String apiKey = Platform.environment['API_KEY'] ?? '';

// Bad - Presentation layer importing data layer
import '../data/user_repository_impl.dart'; // In presentation layer

// Good - Presentation layer importing domain layer
import '../domain/repositories/user_repository.dart'; // In presentation layer

The package provides comprehensive quality scoring:

• Quality Score: Overall code health (0-10.0)
• Performance Score: Widget and rendering efficiency
• Security Score: Vulnerability assessment
• Accessibility Score: WCAG compliance level

Quality Score = 10.0 - (Critical Issues × 2.0 + Warnings × 1.0 + Info × 0.5) / Files Analyzed

# .github/workflows/quality_check.yml
- name: Run Quality Analysis
  run: |
    dart bin/flutter_quality_lints.dart analyze lib
    dart bin/flutter_quality_lints.dart security lib
    dart bin/flutter_quality_lints.dart report json > quality_report.json

{
  "dart.customLintRules": ["flutter_quality_lints"],
  "dart.showIgnoreQuickFixes": true
}

#!/bin/sh
dart bin/flutter_quality_lints.dart analyze lib
if [ $? -ne 0 ]; then
  echo "Quality check failed. Please fix issues before committing."
  exit 1
fi

Full integration with Dart's built-in analyzer for comprehensive coverage.

Many rules support automatic fixes for common patterns.

Deep analysis of widget trees and rebuild patterns.

Enterprise-grade secret detection with pattern matching.

WCAG 2.1 AA compliance checking with actionable recommendations.

We welcome contributions! Please see our Contributing Guide for details.

git clone https://github.com/dvillegastech/flutter_quality_lints.git
cd flutter_quality_lints
dart pub get
dart test

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

• Documentation
• Issue Tracker
• Changelog

Made with by David Villegas