Module: Mocha::API

Includes:
Hooks, ParameterMatchers
Included in:
Integration::MiniTest::Adapter, Integration::TestUnit::Adapter
Defined in:
lib/mocha/api.rb

Overview

Methods added to Test::Unit::TestCase, MiniTest::Unit::TestCase or equivalent. The mock creation methods are #mock, #stub and #stub_everything, all of which return a #Mock which can be further modified by Mock#responds_like and Mock#responds_like_instance_of methods, both of which return a Mock, too, and can therefore, be chained to the original creation methods.

Mock#responds_like and Mock#responds_like_instance_of force the mock to indicate what it is supposed to be mocking, thus making it a safer verifying mock. They check that the underlying responder will actually respond to the methods being stubbed, throwing a NoMethodError upon invocation otherwise.

Examples:

Verifying mock using Mock#responds_like_instance_of

class Sheep
  def initialize
    raise "some awkward code we don't want to call"
  end
  def chew(grass); end
end

sheep = mock('sheep').responds_like_instance_of(Sheep)
sheep.expects(:chew)
sheep.expects(:foo)
sheep.respond_to?(:chew) # => true
sheep.respond_to?(:foo) # => false
sheep.chew
sheep.foo # => raises NoMethodError exception

Instance Method Summary collapse

Methods included from Hooks

#mocha_setup, #mocha_teardown, #mocha_verify

Methods included from ParameterMatchers

#Not, #all_of, #any_of, #any_parameters, #anything, #equals, #equivalent_uri, #has_entries, #has_entry, #has_key, #has_value, #includes, #instance_of, #is_a, #kind_of, #optionally, #regexp_matches, #responds_with, #yaml_equivalent

Instance Method Details

#mock(name) ⇒ Mock #mock(expected_methods_vs_return_values = {}) ⇒ Mock #mock(name, expected_methods_vs_return_values = {}) ⇒ Mock

Builds a new mock object

Examples:

Using expected_methods_vs_return_values Hash to setup expectations.

def test_motor_starts_and_stops
  motor = mock('motor', :start => true, :stop => true)
  assert motor.start
  assert motor.stop
  # an error will be raised unless both Motor#start and Motor#stop have been called
end

Overloads:

  • #mock(name) ⇒ Mock
    Note:

    Prior to v1.10.0 when name was a Symbol, this method returned an unnamed Mock that stubbed the method identified by name. This was undocumented behaviour and it no longer exists.


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# File 'lib/mocha/api.rb', line 68

def mock(*arguments)
  create_mock(arguments) { |mock, expectations| mock.expects(expectations) }
end

#sequence(name) ⇒ Sequence

Builds a new sequence which can be used to constrain the order in which expectations can occur.

Specify that an expected invocation must occur within a named Sequence by using Expectation#in_sequence.

Examples:

Ensure methods on egg are invoked in correct order.

breakfast = sequence('breakfast')

egg = mock('egg') do
  expects(:crack).in_sequence(breakfast)
  expects(:fry).in_sequence(breakfast)
  expects(:eat).in_sequence(breakfast)
end

See Also:


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# File 'lib/mocha/api.rb', line 138

def sequence(name)
  Sequence.new(name)
end

#states(name) ⇒ StateMachine

Builds a new state machine which can be used to constrain the order in which expectations can occur.

Specify the initial state of the state machine by using StateMachine#starts_as.

Specify that an expected invocation should change the state of the state machine by using Expectation#then.

Specify that an expected invocation should be constrained to occur within a particular state by using Expectation#when.

A test can contain multiple state machines.

Examples:

Constrain expected invocations to occur in particular states.

power = states('power').starts_as('off')

radio = mock('radio') do
  expects(:switch_on).then(power.is('on'))
  expects(:select_channel).with('BBC Radio 4').when(power.is('on'))
  expects(:adjust_volume).with(+5).when(power.is('on'))
  expects(:select_channel).with('BBC World Service').when(power.is('on'))
  expects(:adjust_volume).with(-5).when(power.is('on'))
  expects(:switch_off).then(power.is('off'))
end

See Also:


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# File 'lib/mocha/api.rb', line 168

def states(name)
  Mockery.instance.new_state_machine(name)
end

#stub(name) ⇒ Mock #stub(stubbed_methods_vs_return_values = {}) ⇒ Mock #stub(name, stubbed_methods_vs_return_values = {}) ⇒ Mock

Builds a new mock object

Examples:

Using stubbed_methods_vs_return_values Hash to setup stubbed methods.

def test_motor_starts_and_stops
  motor = stub('motor', :start => true, :stop => true)
  assert motor.start
  assert motor.stop
  # an error will not be raised even if either Motor#start or Motor#stop has not been called
end

Overloads:

  • #stub(name) ⇒ Mock
    Note:

    Prior to v1.10.0 when name was a Symbol, this method returned an unnamed Mock that stubbed the method identified by name. This was undocumented behaviour and it no longer exists.


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# File 'lib/mocha/api.rb', line 91

def stub(*arguments)
  create_mock(arguments) { |stub, expectations| stub.stubs(expectations) }
end

#stub_everything(name) ⇒ Mock #stub_everything(stubbed_methods_vs_return_values = {}) ⇒ Mock #stub_everything(name, stubbed_methods_vs_return_values = {}) ⇒ Mock

Builds a mock object that accepts calls to any method. By default it will return nil for any method call.

Examples:

Ignore invocations of irrelevant methods.

def test_motor_stops
  motor = stub_everything('motor', :stop => true)
  assert_nil motor.irrelevant_method_1 # => no error raised
  assert_nil motor.irrelevant_method_2 # => no error raised
  assert motor.stop
end

Overloads:

  • #stub_everything(name) ⇒ Mock
    Note:

    Prior to v1.10.0 when name was a Symbol, this method returned an unnamed Mock that stubbed everything. This was undocumented behaviour and it no longer exists.


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# File 'lib/mocha/api.rb', line 115

def stub_everything(*arguments)
  create_mock(arguments) do |stub, expectations|
    stub.stub_everything
    stub.stubs(expectations)
  end
end