概要
This skill provides a comprehensive framework for testing Ruby on Rails applications using an opinionated, Minitest-first approach. It strictly enforces the Red-Green-Refactor cycle, ensuring that no implementation code is written without a preceding failing test. By focusing on Rails-native tools like fixtures and integration tests while explicitly forbidding RSpec and heavy system tests, it facilitates a fast, lightweight, and reliable testing environment. It includes specialized patterns for model validations, associations, scopes, and external dependency mocking via WebMock to maintain deterministic test results.