rspec-skill

name rspec-skill description Generates RSpec tests in Ruby with describe/context/it blocks, matchers, let/before hooks, and mocking. Use when user mentions "RSpec", "describe do", "expect().to", "Ruby test". Triggers on: "RSpec", "expect().to eq()", "describe do", "Ruby test", "spec file". languages ["Ruby"] category unit-testing license MIT metadata {"author":"TestMu AI","version":"1.0"} RSpec Testing Skill Core Patterns Basic Test RSpec .describe Calculator do subject( :calculator ) { described_class.new } describe '#add' do it 'adds two positive numbers' do expect(calculator.add( 2 , 3 )).to eq( 5 ) end it 'handles negative numbers' do expect(calculator.add(- 1 , 1 )).to eq( 0 ) end end describe '#divide' do it 'divides evenly' do expect(calculator.divide( 10 , 2 )).to eq( 5 ) end it 'raises on zero divisor' do expect { calculator.divide( 10 , 0 ) }.to raise_error( ZeroDivisionError ) end end end Matchers # Equality expect(actual).to eq(expected) # == expect(actual).to eql(expected) # eql? expect(actual).to equal(expected) # equal? (same object) expect(actual).to be(expected) # equal? # Comparison expect(value).to be > 5 expect(value).to be_between( 1 , 10 ).inclusive # Truthiness expect(value).to be_truthy expect(value).to be_falsey expect(value).to be_nil # Collections expect(array).to include ( 3 ) expect(array).to contain_exactly( 1 , 2 , 3 ) expect(array).to match_array([ 3 , 1 , 2 ]) expect(hash).to include ( name: 'Alice' ) # Strings expect(str).to include ( 'hello' ) expect(str).to start_with( 'He' ) expect(str).to match( /\d+/ ) # Types expect(obj).to be_a( String ) expect(obj).to be_an_instance_of( MyClass ) # Exceptions expect { method }.to raise_error( StandardError ) expect { method }.to raise_error( StandardError , /message/ ) # Change expect { user.activate }.to change(user, :active ).from( false ).to( true ) expect { list.push( 1 ) }.to change(list, :size ).by( 1 ) Hooks and Let RSpec .describe UserService do let( :repo ) { instance_double( UserRepository ) } let( :service ) { described_class.new(repo) } before( :each ) do allow(repo).to receive( :save ).and_return( true ) end after( :each ) { cleanup } before( :all ) { setup_database } after( :all ) { teardown_database } context 'when creating a user' do it 'saves to repository' do service.create( 'Alice' , 'alice@test.com' ) expect(repo).to have_received( :save ).once end end end Mocking and Stubbing # Doubles user = double( 'User' , name: 'Alice' , email: 'alice@test.com' ) user = instance_double( User , name: 'Alice' ) # Stubs allow(service).to receive( :fetch ).and_return(data) allow(service).to receive( :fetch ).with( 'id' ).and_return(user) # Expectations expect(service).to receive( :save ).once expect(service).to receive( :notify ).with( 'alice@test.com' ) expect(service).not_to receive( :delete ) Shared Examples RSpec .shared_examples 'a valid model' do it { is_expected.to be_valid } it { is_expected.to respond_to( :save ) } end RSpec .describe User do subject { described_class.new( name: 'Alice' ) } it_behaves_like 'a valid model' end Anti-Patterns Bad Good Why before with heavy setup let (lazy) Only evaluates when used No contexts context 'when...' Clear scenarios Instance variables let blocks Cleaner, lazier should syntax expect().to Modern RSpec Setup: gem install rspec then rspec --init Run: bundle exec rspec or rspec spec/models/user_spec.rb Config: .rspec file with --format documentation --color Deep Patterns For advanced patterns, debugging guides, CI/CD integration, and best practices, see reference/playbook.md .