Missing built in matchers

[sagmor]

This is the list of pending matchers based on RSpec's Built in Matchers

Object identity

• expect(actual).to be(expected) # passes if actual.equal?(expected)

Object equivalence

• expect(actual).to eq(expected) # passes if actual == expected

Optional APIs for identity/equivalence

• expect(actual).to eql(expected) # passes if actual.eql?(expected)
• expect(actual).to equal(expected) # passes if actual.equal?(expected)

Comparisons

• expect(actual).to be > expected
• expect(actual).to be >= expected
• expect(actual).to be <= expected
• expect(actual).to be < expected
• expect(actual).to be_between(minimum, maximum).inclusive
• expect(actual).to be_between(minimum, maximum).exclusive
• expect(actual).to match(/expression/)
• expect(actual).to be_within(delta).of(expected)
• expect(actual).to start_with expected
• expect(actual).to end_with expected

Types/classes/response

• expect(actual).to be_instance_of(expected)
• expect(actual).to be_kind_of(expected)
• expect(actual).to respond_to(expected)

Truthiness and existentialism

• expect(actual).to be_truthy # passes if actual is truthy (not nil or false)
• expect(actual).to be true # passes if actual == true
• expect(actual).to be_falsey # passes if actual is falsy (nil or false)
• expect(actual).to be false # passes if actual == false
• expect(actual).to be_nil # passes if actual is nil
• expect(actual).to exist # passes if actual.exist? and/or actual.exists? are truthy
• expect(actual).to exist(_args) # passes if actual.exist?(_args) and/or actual.exists?(*args) are truthy

Expecting errors

• expect { ... }.to raise_error
• expect { ... }.to raise_error(ErrorClass)
• expect { ... }.to raise_error("message")
• expect { ... }.to raise_error(ErrorClass, "message")

Expecting throws

• expect { ... }.to throw_symbol
• expect { ... }.to throw_symbol(:symbol)
• expect { ... }.to throw_symbol(:symbol, 'value')

Predicate matchers

• expect(actual).to be_xxx # passes if actual.xxx?
• expect(actual).to have_xxx(:arg) # passes if actual.has_xxx?(:arg)

Collection membership

• expect(actual).to include(expected)
• expect(array).to match_array(expected_array)
• expect(array).to contain_exactly(individual, elements)

Ranges

• expect(1..10).to cover(3)

Change observation

• expect { object.action }.to change(object, :value).from(old).to(new)
• expect { object.action }.to change(object, :value).by(delta)
• expect { object.action }.to change(object, :value).by_at_least(minimum_delta)
• expect { object.action }.to change(object, :value).by_at_most(maximum_delta)

Satisfy

• expect(actual).to satisfy { |value| value == expected }

Output capture

• expect { actual }.to output("some output").to_stdout
• expect { actual }.to output("some error").to_stderr

Block expectation

• expect { |b| object.action(&b) }.to yield_control
• expect { |b| object.action(&b) }.to yield_with_no_args # only matches no args
• expect { |b| object.action(&b) }.to yield_with_args # matches any args
• expect { |b| object.action(&b) }.to yield_successive_args(*args) # matches args against multiple yields