# 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

- #mock(*arguments) ⇒ Mock

  Builds a new mock object.

- #sequence(name) { ... } ⇒ Sequence

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

- #states(name) ⇒ StateMachine

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

- #stub(*arguments) ⇒ Mock

  Builds a new mock object.

- #stub_everything(*arguments) ⇒ Mock

  Builds a mock object that accepts calls to any method.

### Methods included from Hooks

#mocha_setup, #mocha_teardown, #mocha_test_name, #mocha_verify

### Methods included from ParameterMatchers

#Not, #all_of, #any_of, #any_parameters, #anything, #equals, #equivalent_uri, #has_entries, #has_entry, #has_key, #has_keys, #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`

  Parameters:

  - name (`String`, `Symbol`) —

    identifies mock object in error messages.

- #mock(expected_methods_vs_return_values = {}) ⇒ `Mock`

  Parameters:

  - expected_methods_vs_return_values (`Hash`) (defaults to: `{}`) —

    expected method name symbols as keys and corresponding return values as values - these expectations are setup as if Mock#expects were called multiple times.

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

  Parameters:

  - name (`String`, `Symbol`) —

    identifies mock object in error messages.

  - expected_methods_vs_return_values (`Hash`) (defaults to: `{}`) —

    expected method name symbols as keys and corresponding return values as values - these expectations are setup as if Mock#expects were called multiple times.

Returns:

- (`Mock`) —

  a new mock object

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    # File 'lib/mocha/api.rb', line 69

    def mock(*arguments)
      name = arguments.shift.to_s if arguments.first.is_a?(String) || arguments.first.is_a?(Symbol)
      expectations = arguments.shift || {}
      mock = name ? Mockery.instance.named_mock(name) : Mockery.instance.unnamed_mock
      mock.expects(expectations)
      mock
    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 calling Expectation#in_sequence on each expectation or by passing a block within which all expectations should be constrained by the Sequence.

#### Examples:

#####

Ensure methods on egg are invoked in correct order.

    breakfast = sequence('breakfast')

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

#####

Ensure methods across multiple objects are invoked in correct order.

    sequence = sequence(:task_order)

    task_one = mock("task_one")
    task_two = mock("task_two")

    task_one.expects(:execute).in_sequence(sequence)
    task_two.expects(:execute).in_sequence(sequence)

    task_one.execute
    task_two.execute

#####

Ensure methods on egg are invoked in the correct order using a block.

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

Parameters:

- name (`String`) —

  name of sequence

Yields:

- optional block within which expectations should be constrained by the sequence

Returns:

- (`Sequence`) —

  a new sequence

See Also:

- Expectation#in_sequence

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    # File 'lib/mocha/api.rb', line 170

    def sequence(name)
      Sequence.new(name).tap do |seq|
        Mockery.instance.sequences.push(seq)
        begin
          yield if block_given?
        ensure
          Mockery.instance.sequences.pop
        end
      end
    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')
    radio.expects(:switch_on).then(power.is('on'))
    radio.expects(:select_channel).with('BBC Radio 4').when(power.is('on'))
    radio.expects(:adjust_volume).with(+5).when(power.is('on'))
    radio.expects(:select_channel).with('BBC World Service').when(power.is('on'))
    radio.expects(:adjust_volume).with(-5).when(power.is('on'))
    radio.expects(:switch_off).then(power.is('off'))

Parameters:

- name (`String`) —

  name of state machine

Returns:

- (`StateMachine`) —

  a new state machine

See Also:

- Expectation#then
- Expectation#when
- StateMachine

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    # File 'lib/mocha/api.rb', line 207

    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`

  Parameters:

  - name (`String`, `Symbol`) —

    identifies mock object in error messages.

- #stub(stubbed_methods_vs_return_values = {}) ⇒ `Mock`

  Parameters:

  - stubbed_methods_vs_return_values (`Hash`) (defaults to: `{}`) —

    stubbed method name symbols as keys and corresponding return values as values - these stubbed methods are setup as if Mock#stubs were called multiple times.

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

  Parameters:

  - name (`String`, `Symbol`) —

    identifies mock object in error messages.

  - stubbed_methods_vs_return_values (`Hash`) (defaults to: `{}`) —

    stubbed method name symbols as keys and corresponding return values as values - these stubbed methods are setup as if Mock#stubs were called multiple times.

Returns:

- (`Mock`) —

  a new mock object

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    # File 'lib/mocha/api.rb', line 96

    def stub(*arguments)
      name = arguments.shift.to_s if arguments.first.is_a?(String) || arguments.first.is_a?(Symbol)
      expectations = arguments.shift || {}
      stub = name ? Mockery.instance.named_mock(name) : Mockery.instance.unnamed_mock
      stub.stubs(expectations)
      stub
    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`

  Parameters:

  - name (`String`, `Symbol`) —

    identifies mock object in error messages.

- #stub_everything(stubbed_methods_vs_return_values = {}) ⇒ `Mock`

  Parameters:

  - stubbed_methods_vs_return_values (`Hash`) (defaults to: `{}`) —

    stubbed method name symbols as keys and corresponding return values as values - these stubbed methods are setup as if Mock#stubs were called multiple times.

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

  Parameters:

  - name (`String`, `Symbol`) —

    identifies mock object in error messages.

  - stubbed_methods_vs_return_values (`Hash`) (defaults to: `{}`) —

    stubbed method name symbols as keys and corresponding return values as values - these stubbed methods are setup as if Mock#stubs were called multiple times.

Returns:

- (`Mock`) —

  a new mock object

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    # File 'lib/mocha/api.rb', line 123

    def stub_everything(*arguments)
      name = arguments.shift if arguments.first.is_a?(String) || arguments.first.is_a?(Symbol)
      expectations = arguments.shift || {}
      stub = name ? Mockery.instance.named_mock(name) : Mockery.instance.unnamed_mock
      stub.stub_everything
      stub.stubs(expectations)
      stub
    end