import_guard_custom_lint #

A custom_lint package to guard imports between packages and folders.

日本語版 README

Note: For Dart 3.10+, consider using import_guard which uses the native analyzer plugin API with better IDE integration.

Features #

• Define import restrictions per folder using import_guard.yaml
• Glob patterns: package:my_app/data/**, package:flutter/**
• Works with package imports and relative imports
• Hierarchical config inheritance from repo root
• Allow list support for exceptions

Installation #

dev_dependencies:
  import_guard_custom_lint: ^0.0.7
  custom_lint: ^0.7.0

Enable in analysis_options.yaml:

analyzer:
  plugins:
    - custom_lint

Usage #

Create import_guard.yaml in any directory to define restrictions for files in that directory.

Configuration Options #

# Deny specific imports (files in this directory cannot import these)
deny:
  - package:my_app/presentation/**
  - package:my_app/data/**
  - dart:mirrors

# Allow specific imports (exceptions to deny rules, or whitelist mode)
allow:
  - package:my_app/domain/**
  - dart:core

# Inherit rules from parent directories (default: true)
inherit: true

Example: Clean Architecture #

For a Flutter app named my_app:

my_app/
├── pubspec.yaml          # name: my_app
├── import_guard.yaml     # Root-level rules (apply to entire project)
└── lib/
    ├── domain/
    │   ├── import_guard.yaml  # Domain-specific rules
    │   └── user.dart
    ├── presentation/
    │   └── user_page.dart
    └── data/
        └── user_repository.dart

Root-level config:

# import_guard.yaml
deny:
  - dart:mirrors  # Deny in entire project

Domain layer config:

# lib/domain/import_guard.yaml
deny:
  - package:my_app/presentation/**
  - package:my_app/data/**

This prevents domain layer from importing presentation or data layers.

Pattern Types #

Recommended: Use package imports #

To simplify configuration, enable always_use_package_imports:

# analysis_options.yaml
linter:
  rules:
    - always_use_package_imports

Then you only need to write package patterns (no relative path patterns needed).

Running #

dart run custom_lint

Related Packages #

• import_guard - Native analyzer plugin (Dart 3.10+)

License #

MIT