dart-matcher-best-practices

What problem does it solve?

This Skill helps developers write more readable, maintainable, and effective assertions in their Dart tests by leveraging the full power of package:matcher. It guides users away from common pitfalls and towards best practices for clearer test failures.

Core Features & Use Cases

• Readable Assertions: Learn to use matchers like hasLength, contains, isEmpty, and isA<T> for clearer intent.
• Effective Property Checking: Utilize .having() for detailed object property assertions.
• Robust Async Testing: Master completion() and throwsA() with expectLater for reliable asynchronous tests.
• Use Case: When writing a test for a function that returns a list, instead of checking list.length == 5 and then iterating to check contents, use expect(list, allOf([hasLength(5), contains('expected_item')])) for a more concise and informative assertion.

Quick Start

Use the dart-matcher-best-practices skill to refactor a test assertion from checking list.length to using hasLength.