A comprehensive custom lint library for Dart/Flutter projects with 13 carefully crafted lint rules to enforce best practices, improve code quality, and ensure robust testing standards.

Lint Rules #

Error-Level Rules

• forbid_forced_unwrapping: Forbids forced unwrapping (!) in production code. Exceptions: test files, /testing/ fakes, and generated files (.freezed.dart, .g.dart).

• no_optional_operators_in_tests: Forbids optional operators (?., ??) in test files to ensure explicit test failures.

• no_direct_instantiation: Enforces dependency injection by forbidding direct class instantiation. Exceptions: Module and Factory classes.

• document_fake_parameters: Requires documentation on Fake classes and their non-private members.

• document_interface: Requires documentation on abstract classes and their public methods.

• test_file_mutation_coverage: Ensures every test file in test/units has a corresponding .xml mutation file in test/mutations.

• private_subject: Requires Subject variables (BehaviorSubject, ReplaySubject, PublishSubject) to be private with underscore prefix.

• sealed_over_dynamic: Enforces sealed classes instead of dynamic for type-safe sync results.

• specific_exception_types: Requires specific exception types instead of generic Exception.

Warning-Level Rules

• prefer_fake_over_mock: Recommends Fake over Mock for test doubles.

• todo_with_story_links: Requires TODO comments to include YouTrack story links.

• no_internal_method_docs: Forbids documentation on private methods to reduce noise.

• avoid_test_timeouts: Forbids .timeout() and Future.delayed() in tests to prevent flaky tests.

Features #

• Clean architecture with base analyzer and lint rule classes
• Extensible framework for adding custom rules
• Comprehensive test coverage for all rules
• Example files demonstrating violations and correct usage
• Support for custom lint configuration via custom_lint.yaml
• Integration with Dart analyzer and IDE support