lint_barrel_self_import

A custom lint rule to avoid importing a package's own barrel file from within that package.

Problem

When developing Dart packages, it's common to create a "barrel file" (e.g., package_name.dart) that re-exports all public APIs. However, importing this barrel file from within the same package can lead to:

  • Circular dependency issues
  • Unnecessary indirection
  • Performance overhead
  • Maintenance complexity

Solution

This lint rule detects and warns against importing a package's own barrel file from within that package, whether through:

  • package: URI imports (e.g., import 'package:my_package/my_package.dart';)
  • Relative path imports (e.g., import './my_package.dart'; or import '../lib/my_package.dart';)

Installation

Add the following to your pubspec.yaml:

dev_dependencies:
  custom_lint: ^0.6.4
  lint_barrel_self_import: ^0.1.0

Then run:

dart pub get

Usage

Add the following to your analysis_options.yaml:

analyzer:
  plugins:
    - custom_lint

Examples

❌ Bad (will trigger warnings)

// In lib/src/some_file.dart
import 'package:my_package/my_package.dart'; // Warning: avoid importing barrel file

// In lib/src/another_file.dart  
import '../my_package.dart'; // Warning: avoid importing barrel file

// In lib/nested/deep_file.dart
import '../../lib/my_package.dart'; // Warning: avoid importing barrel file

✅ Good (no warnings)

// In lib/src/some_file.dart
import 'another_file.dart'; // OK: importing other files within package
import 'package:other_package/other_package.dart'; // OK: importing other packages

// In lib/src/another_file.dart
import '../utils/helper.dart'; // OK: importing specific files

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

License

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

Libraries

lint_barrel_self_import
A custom lint rule to avoid importing a package's own barrel file from within that package.