Generate RSpec Tests for Ruby Code

The skill generates RSpec test suites following the Arrange-Act-Assert pattern and RSpec's own organizing conventions: describe blocks for classes/modules and methods, context blocks for different conditions, example descriptions starting with a verb ("returns", "raises", "updates"), and let/let! for test data instead of instance variables. For an instance method, each distinct condition gets its own nested context - a #full_name method, for instance, gets separate contexts for "when both first and last name are present" versus "when last name is missing", each with its own let(:user) setup and expectation.

Use it to generate specs for the three common Rails testing targets. A model spec checks validations, associations and scopes with shoulda-style one-liners plus behavior-specific examples:

RSpec.describe User, type: :model do
  describe 'validations' do
    subject { build(:user) }
    
    it { should validate_presence_of(:email) }
    it { should validate_uniqueness_of(:email).case_insensitive }
    it { should validate_length_of(:password).is_at_least(8) }
  end
  
  describe 'associations' do
    it { should have_many(:posts).dependent(:destroy) }
    it { should belong_to(:organization) }
  end
end

A controller spec checks response status, assigns, and redirect/render targets across valid and invalid parameter cases. A service-object spec checks the result object's success?/errors and any side effects, such as expecting UserMailer to receive :welcome_email. It is not a generic Ruby testing skill - it assumes RSpec plus common Rails testing gems (FactoryBot-style build/create, shoulda matchers).

Input is the Ruby/Rails class to test - a model, controller, or service object. Output is a .rb spec file structured with nested describe/context blocks, plus supporting constructs: mocking and stubbing (allow(...).to receive(...).and_return(...), expect(...).to have_received(...), stubbing Time.current for deterministic time-based tests), RSpec.shared_examples for behavior shared across models (e.g. "an auditable model" checking created_at/updated_at), and custom matchers defined with RSpec::Matchers.define.

It configures spec_helper.rb itself where relevant: verify_partial_doubles = true for safer mocks, disable_monkey_patching!, randomized run order with a seeded RNG, and filter_run_when_matching :focus for iterating on one spec. Performance and quality guidance favors build over create when persistence isn't needed, aggregate_failures for multiple related expectations in one example, travel_to over stubbing Time.now for time-based tests, and proper database-cleaning strategy for test isolation. It also recommends writing integration tests for critical user workflows on top of the fast, focused unit specs, and using descriptive factory traits to express different test scenarios.

Ruby/Rails developers who want idiomatic, well-organized RSpec specs generated for models, controllers and service objects - with the mocking, shared examples and configuration that make a test suite maintainable, not just a pile of passing examples.