ruby-minitest-testing

name	ruby-minitest-testing
description	Minitest patterns for Ruby and Rails: assertions, parallel tests, fixtures, and Rails 8 default test stack. Use when working in `test/` directories or Minitest-only projects.

Minitest Testing

Use Minitest effectively — Rails 8's default — with clear structure and parallel execution.

When to Use This Skill

• Writing test/ files in Rails
• Converting from RSpec
• Speeding up unit tests

Defaults (This Plugin)

• Toolchain: mise — not rbenv, rvm, or asdf directly
• Ruby: 4.0.0+ unless the project pins otherwise
• Rails: 8+ conventions and generators when applicable
• Execution: Prefer mise exec --, bin/rails, bin/rspec, and bundle exec

Core Guidance

1. Rails generators produce Minitest by default unless configured for RSpec.

2. Parallelize in test_helper.rb when tests are isolated:

parallelize(workers: :number_of_processors)

1. Fixtures for stable baseline data; factories (factory_bot) only if already adopted.

2. Integration vs system: Use ActionDispatch::IntegrationTest for HTTP; system tests for full browser (Cuprite/Selenium).

3. Run:

mise exec -- bin/rails test
mise exec -- bin/rails test test/models/user_test.rb

Quick Commands

mise exec -- bin/rails test
mise exec -- bin/rails test:system
mise exec -- PARALLEL_WORKERS=4 bin/rails test

Anti-Patterns

• Disabling transactional tests without cleaning DB
• Sleep-based timing instead of perform_enqueued_jobs

See Also

• rails-testing
• ruby-rspec-testing