Class: RSpec::Mocks::MessageExpectation

Relationships & Source Files
Namespace Children
Modules: `ImplementationDetails`
Extension / Inclusion / Inheritance Descendants
Subclasses: RSpec::Mocks::VerifyingMessageExpectation
Super Chains via Extension / Inclusion / Inheritance
Instance Chain: self, `ImplementationDetails`
Inherits:	Object
Defined in:	rspec-mocks/lib/rspec/mocks/message_expectation.rb

Overview

Represents an individual method stub or message expectation. The methods defined here can be used to configure how it behaves. The methods return ‘self` so that they can be chained together to form a fluent interface.

Configuring Responses

#and_call_original ⇒ nil

Tells the object to delegate to the original unmodified method when it receives the message.
#and_invoke(first_proc, *procs) ⇒ nil

Tells the object to invoke a Proc when it receives the message.
#and_raise ⇒ nil

Tells the object to raise an exception when the message is received.
#and_return(value) ⇒ nil

Tells the object to return a value when it receives the message.
#and_throw(symbol) ⇒ nil

Tells the object to throw a symbol (with the object if that form is used) when the message is received.
#and_wrap_original(&block) ⇒ nil

Decorates the stubbed method with the supplied block.
#and_yield(*args) {|@eval_context = Object.new| ... } ⇒ MessageExpectation

Tells the object to yield one or more args to a block when the message is received.

Constraining Receive Counts

#at_least(n, &block) ⇒ MessageExpectation

Constrain a message expectation to be received at least a specific number of times.
#at_most(n, &block) ⇒ MessageExpectation

Constrain a message expectation to be received at most a specific number of times.
#exactly(n, &block) ⇒ MessageExpectation

Constrain a message expectation to be received a specific number of times.
#never ⇒ MessageExpectation

Expect a message not to be received at all.
#once(&block) ⇒ MessageExpectation

Expect a message to be received exactly one time.
#thrice(&block) ⇒ MessageExpectation

Expect a message to be received exactly three times.
#time(&block)

Alias for #times.
#times(&block) ⇒ MessageExpectation (also: #time)

Syntactic sugar for ‘exactly`, #at_least and #at_most.
#twice(&block) ⇒ MessageExpectation

Expect a message to be received exactly two times.

Other Constraints

#inspect

Alias for #to_s.
#ordered(&block) ⇒ MessageExpectation

Expect messages to be received in a specific order.
#to_s ⇒ String (also: #inspect)
#with(*args, &block) ⇒ MessageExpectation

Constrains a stub or message expectation to invocations with specific arguments.

Instance Attribute Summary

Instance Method Summary

`ImplementationDetails` - Included

#additional_expected_calls, #advise, #and_yield_receiver_to_implementation, #description_for, #ensure_expected_ordering_received!, #expectation_count_type, #expected_args, #generate_error, #increase_actual_received_count!, #initialize, #invoke, #invoke_without_incrementing_received_count, #matches?, #matches_name_but_not_args, #negative_expectation_for?, #raise_out_of_order_error, #raise_unexpected_message_args_error, #safe_invoke, #similar_messages, #unadvise, #verify_messages_received, #exception_source_id, #invoke_incrementing_actual_calls_by, #raise_already_invoked_error_if_necessary, #set_expected_received_count, #warn_about_stub_override, #wrap_original

Instance Method Details

#and_call_original ⇒ `nil`

Note:

This is only available on partial doubles.

Tells the object to delegate to the original unmodified method when it receives the message.

Examples:

expect(counter).to receive(:increment).and_call_original
original_count = counter.count
counter.increment
expect(counter.count).to eq(original_count + 1)

Returns:

(nil) —

No further chaining is supported after this.

[ GitHub ]

# File 'rspec-mocks/lib/rspec/mocks/message_expectation.rb', line 141


def and_call_original
  block = lambda do |original, *args, &b|
    original.call(*args, &b)
  end
  block = block.ruby2_keywords if block.respond_to?(:ruby2_keywords)

  wrap_original(__method__, &block)
end

#and_invoke(first_proc, *procs) ⇒ `nil`

Tells the object to invoke a Proc when it receives the message. Given more than one value, the result of the first Proc is returned the first time the message is received, the result of the second Proc is returned the next time, etc, etc.

If the message is received more times than there are Procs, the result of the last Proc is returned for every subsequent call.

Examples:

allow(api).to receive(:get_foo).and_invoke(-> { raise ApiTimeout })
api.get_foo # => raises ApiTimeout
api.get_foo # => raises ApiTimeout

allow(api).to receive(:get_foo).and_invoke(-> { raise ApiTimeout }, -> { raise ApiTimeout }, -> { :a_foo })
api.get_foo # => raises ApiTimeout
api.get_foo # => raises ApiTimeout
api.get_foo # => :a_foo
api.get_foo # => :a_foo
api.get_foo # => :a_foo
# etc

Returns:

(nil) —

No further chaining is supported after this.

[ GitHub ]

# File 'rspec-mocks/lib/rspec/mocks/message_expectation.rb', line 109


def and_invoke(first_proc, *procs)
  raise_already_invoked_error_if_necessary(__method__)
  if negative?
    raise "`and_invoke` is not supported with negative message expectations"
  end

  if block_given?
    raise ArgumentError, "Implementation blocks aren't supported with `and_invoke`"
  end

  procs.unshift(first_proc)
  if procs.any? { |p| !p.respond_to?(:call) }
    raise ArgumentError, "Arguments to `and_invoke` must be callable."
  end

  @expected_received_count = [@expected_received_count, procs.size].max unless ignoring_args? || (@expected_received_count == 0 && @at_least)
  self.terminal_implementation_action = AndInvokeImplementation.new(procs)

  nil
end

#and_raise ⇒ `nil` #and_raise(ExceptionClass) ⇒ `nil` #and_raise(ExceptionClass, message) ⇒ `nil` #and_raise(exception_instance) ⇒ `nil`

Note:

When you pass an exception class, the MessageExpectation will raise an instance of it, creating it with ‘exception` and passing message if specified. If the exception class initializer requires more than one parameters, you must pass in an instance and not the class, otherwise this method will raise an ArgumentError exception.

Tells the object to raise an exception when the message is received.

Examples:

allow(car).to receive(:go).and_raise
allow(car).to receive(:go).and_raise(OutOfGas)
allow(car).to receive(:go).and_raise(OutOfGas, "At least 2 oz of gas needed to drive")
allow(car).to receive(:go).and_raise(OutOfGas.new(2, :oz))

Returns:

(nil) —

No further chaining is supported after this.

[ GitHub ]

# File 'rspec-mocks/lib/rspec/mocks/message_expectation.rb', line 186


def and_raise(*args)
  raise_already_invoked_error_if_necessary(__method__)
  self.terminal_implementation_action = Proc.new { raise(*args) }
  nil
end

#and_return(value) ⇒ `nil` #and_return(first_value, second_value) ⇒ `nil`

Tells the object to return a value when it receives the message. Given more than one value, the first value is returned the first time the message is received, the second value is returned the next time, etc, etc.

If the message is received more times than there are values, the last value is returned for every subsequent call.

Examples:

allow(counter).to receive(:count).and_return(1)
counter.count # => 1
counter.count # => 1

allow(counter).to receive(:count).and_return(1,2,3)
counter.count # => 1
counter.count # => 2
counter.count # => 3
counter.count # => 3
counter.count # => 3
# etc

Returns:

(nil) —

No further chaining is supported after this.

[ GitHub ]

# File 'rspec-mocks/lib/rspec/mocks/message_expectation.rb', line 71


def and_return(first_value, *values)
  raise_already_invoked_error_if_necessary(__method__)
  if negative?
    raise "`and_return` is not supported with negative message expectations"
  end

  if block_given?
    raise ArgumentError, "Implementation blocks aren't supported with `and_return`"
  end

  values.unshift(first_value)
  @expected_received_count = [@expected_received_count, values.size].max unless ignoring_args? || (@expected_received_count == 0 && @at_least)
  self.terminal_implementation_action = AndReturnImplementation.new(values)

  nil
end

#and_throw(symbol) ⇒ `nil` #and_throw(symbol, object) ⇒ `nil`

Tells the object to throw a symbol (with the object if that form is used) when the message is received.

Examples:

allow(car).to receive(:go).and_throw(:out_of_gas)
allow(car).to receive(:go).and_throw(:out_of_gas, :level => 0.1)

Returns:

(nil) —

No further chaining is supported after this.

[ GitHub ]

# File 'rspec-mocks/lib/rspec/mocks/message_expectation.rb', line 202


def and_throw(*args)
  raise_already_invoked_error_if_necessary(__method__)
  self.terminal_implementation_action = Proc.new { throw(*args) }
  nil
end

#and_wrap_original(&block) ⇒ `nil`

Note:

This is only available on partial doubles.

Decorates the stubbed method with the supplied block. The original unmodified method is passed to the block along with any method call arguments so you can delegate to it, whilst still being able to change what args are passed to it and/or change the return value.

Examples:

expect(api).to receive(:large_list).and_wrap_original do |original_method, *args, &block|
  original_method.call(*args, &block).first(10)
end

Returns:

(nil) —

No further chaining is supported after this.

[ GitHub ]

# File 'rspec-mocks/lib/rspec/mocks/message_expectation.rb', line 162


def and_wrap_original(&block)
  wrap_original(__method__, &block)
end

#and_yield(*args) {|@eval_context = Object.new| ... } ⇒ `MessageExpectation`

Tells the object to yield one or more args to a block when the message is received.

Examples:

stream.stub(:open).and_yield(StringIO.new)

Yields:

(@eval_context = Object.new)

Returns:

(MessageExpectation) —

self, to support further chaining.

[ GitHub ]

# File 'rspec-mocks/lib/rspec/mocks/message_expectation.rb', line 214


def and_yield(*args, &block)
  raise_already_invoked_error_if_necessary(__method__)
  yield @eval_context = Object.new if block

  # Initialize args to yield now that it's being used, see also: comment
  # in constructor.
  @args_to_yield ||= []

  @args_to_yield << args
  self.initial_implementation_action = AndYieldImplementation.new(@args_to_yield, @eval_context, @error_generator)
  self
end

#at_least(n, &block) ⇒ `MessageExpectation`

Constrain a message expectation to be received at least a specific number of times.

Examples:

expect(dealer).to receive(:deal_card).at_least(9).times

Returns:

(MessageExpectation) —

self, to support further chaining.

[ GitHub ]

# File 'rspec-mocks/lib/rspec/mocks/message_expectation.rb', line 249


def at_least(n, &block)
  raise_already_invoked_error_if_necessary(__method__)
  set_expected_received_count :at_least, n

  if n == 0
    raise "at_least(0) has been removed, use allow(...).to receive(:message) instead"
  end

  self.inner_implementation_action = block

  self
end

#at_most(n, &block) ⇒ `MessageExpectation`

Constrain a message expectation to be received at most a specific number of times.

Examples:

expect(dealer).to receive(:deal_card).at_most(10).times

Returns:

(MessageExpectation) —

self, to support further chaining.

[ GitHub ]

# File 'rspec-mocks/lib/rspec/mocks/message_expectation.rb', line 268


def at_most(n, &block)
  raise_already_invoked_error_if_necessary(__method__)
  self.inner_implementation_action = block
  set_expected_received_count :at_most, n
  self
end

#exactly(n, &block) ⇒ `MessageExpectation`

Constrain a message expectation to be received a specific number of times.

Examples:

expect(dealer).to receive(:deal_card).exactly(10).times

Returns:

(MessageExpectation) —

self, to support further chaining.

[ GitHub ]

# File 'rspec-mocks/lib/rspec/mocks/message_expectation.rb', line 236


def exactly(n, &block)
  raise_already_invoked_error_if_necessary(__method__)
  self.inner_implementation_action = block
  set_expected_received_count :exactly, n
  self
end

#inspect

Alias for #to_s.

[ GitHub ]

# File 'rspec-mocks/lib/rspec/mocks/message_expectation.rb', line 401


alias inspect to_s

#never ⇒ `MessageExpectation`

Expect a message not to be received at all.

Examples:

expect(car).to receive(:stop).never

Returns:

(MessageExpectation) —

self, to support further chaining.

[ GitHub ]

# File 'rspec-mocks/lib/rspec/mocks/message_expectation.rb', line 293


def never
  error_generator.raise_double_negation_error("expect(obj)") if negative?
  @expected_received_count = 0
  self
end

#once(&block) ⇒ `MessageExpectation`

Expect a message to be received exactly one time.

Examples:

expect(car).to receive(:go).once

Returns:

(MessageExpectation) —

self, to support further chaining.

[ GitHub ]

# File 'rspec-mocks/lib/rspec/mocks/message_expectation.rb', line 304


def once(&block)
  self.inner_implementation_action = block
  set_expected_received_count :exactly, 1
  self
end

#ordered(&block) ⇒ `MessageExpectation`

Expect messages to be received in a specific order.

Examples:

expect(api).to receive(:prepare).ordered
expect(api).to receive(:run).ordered
expect(api).to receive(:finish).ordered

Returns:

(MessageExpectation) —

self, to support further chaining.

[ GitHub ]

# File 'rspec-mocks/lib/rspec/mocks/message_expectation.rb', line 379


def ordered(&block)
  if type == :stub
    RSpec.warning(
      "`allow(...).to receive(..).ordered` is not supported and will " \
      "have no effect, use `and_return(*ordered_values)` instead."
    )
  end

  self.inner_implementation_action = block
  additional_expected_calls.times do
    @order_group.register(self)
  end
  @ordered = true
  self
end

#thrice(&block) ⇒ `MessageExpectation`

Expect a message to be received exactly three times.

Examples:

expect(car).to receive(:go).thrice

Returns:

(MessageExpectation) —

self, to support further chaining.

[ GitHub ]

# File 'rspec-mocks/lib/rspec/mocks/message_expectation.rb', line 326


def thrice(&block)
  self.inner_implementation_action = block
  set_expected_received_count :exactly, 3
  self
end

#time(&block)

Alias for #times.

[ GitHub ]

# File 'rspec-mocks/lib/rspec/mocks/message_expectation.rb', line 286


alias time times

#times(&block) ⇒ `MessageExpectation` Also known as: #time

Syntactic sugar for ‘exactly`, #at_least and #at_most

Examples:

expect(dealer).to receive(:deal_card).exactly(10).times
expect(dealer).to receive(:deal_card).at_least(10).times
expect(dealer).to receive(:deal_card).at_most(10).times

Returns:

(MessageExpectation) —

self, to support further chaining.

[ GitHub ]

# File 'rspec-mocks/lib/rspec/mocks/message_expectation.rb', line 282


def times(&block)
  self.inner_implementation_action = block
  self
end

#to_s ⇒ `String` Also known as: #inspect

Returns:

(String) —

a nice representation of the message expectation

[ GitHub ]

# File 'rspec-mocks/lib/rspec/mocks/message_expectation.rb', line 396


def to_s
  args_description = error_generator.method_call_args_description(@argument_list_matcher.expected_args, "", "") { true }
  args_description = "(#{args_description})" unless args_description.start_with?("(")
  "#<#{self.class} #{error_generator.intro}.#{message}#{args_description}>"
end

#twice(&block) ⇒ `MessageExpectation`

Expect a message to be received exactly two times.

Examples:

expect(car).to receive(:go).twice

Returns:

(MessageExpectation) —

self, to support further chaining.

[ GitHub ]

# File 'rspec-mocks/lib/rspec/mocks/message_expectation.rb', line 315


def twice(&block)
  self.inner_implementation_action = block
  set_expected_received_count :exactly, 2
  self
end

#with(*args, &block) ⇒ `MessageExpectation`

Constrains a stub or message expectation to invocations with specific arguments.

With a stub, if the message might be received with other args as well, you should stub a default value first, and then stub or mock the same message using ‘with` to constrain to specific arguments.

A message expectation will fail if the message is received with different arguments.

Examples:

allow(cart).to receive(:add) { :failure }
allow(cart).to receive(:add).with(Book.new(:isbn => 1934356379)) { :success }
cart.add(Book.new(:isbn => 1234567890))
# => :failure
cart.add(Book.new(:isbn => 1934356379))
# => :success

expect(cart).to receive(:add).with(Book.new(:isbn => 1934356379)) { :success }
cart.add(Book.new(:isbn => 1234567890))
# => failed expectation
cart.add(Book.new(:isbn => 1934356379))
# => passes

Returns:

(MessageExpectation) —

self, to support further chaining.

[ GitHub ]

# File 'rspec-mocks/lib/rspec/mocks/message_expectation.rb', line 359


def with(*args, &block)
  raise_already_invoked_error_if_necessary(__method__)
  if args.empty?
    raise ArgumentError,
          "`with` must have at least one argument. Use `no_args` matcher to set the expectation of receiving no arguments."
  end

  self.inner_implementation_action = block
  @argument_list_matcher = ArgumentListMatcher.new(*args)
  self
end

Class: RSpec::Mocks::MessageExpectation

Overview

Configuring Responses

Constraining Receive Counts

Other Constraints

Instance Attribute Summary

ImplementationDetails - Included

Instance Method Summary

ImplementationDetails - Included

Instance Method Details

#and_call_original ⇒ nil

#and_invoke(first_proc, *procs) ⇒ nil

#and_raise ⇒ nil #and_raise(ExceptionClass) ⇒ nil #and_raise(ExceptionClass, message) ⇒ nil #and_raise(exception_instance) ⇒ nil

#and_return(value) ⇒ nil #and_return(first_value, second_value) ⇒ nil

#and_throw(symbol) ⇒ nil #and_throw(symbol, object) ⇒ nil

#and_wrap_original(&block) ⇒ nil

#and_yield(*args) {|@eval_context = Object.new| ... } ⇒ MessageExpectation

#at_least(n, &block) ⇒ MessageExpectation

#at_most(n, &block) ⇒ MessageExpectation

#exactly(n, &block) ⇒ MessageExpectation

#inspect

#never ⇒ MessageExpectation

#once(&block) ⇒ MessageExpectation

#ordered(&block) ⇒ MessageExpectation

#thrice(&block) ⇒ MessageExpectation

#time(&block)

#times(&block) ⇒ MessageExpectation Also known as: #time

#to_s ⇒ String Also known as: #inspect

#twice(&block) ⇒ MessageExpectation

#with(*args, &block) ⇒ MessageExpectation

`ImplementationDetails` - Included

`ImplementationDetails` - Included

#and_call_original ⇒ `nil`

#and_invoke(first_proc, *procs) ⇒ `nil`

#and_raise ⇒ `nil` #and_raise(ExceptionClass) ⇒ `nil` #and_raise(ExceptionClass, message) ⇒ `nil` #and_raise(exception_instance) ⇒ `nil`

#and_return(value) ⇒ `nil` #and_return(first_value, second_value) ⇒ `nil`

#and_throw(symbol) ⇒ `nil` #and_throw(symbol, object) ⇒ `nil`

#and_wrap_original(&block) ⇒ `nil`

#and_yield(*args) {|@eval_context = Object.new| ... } ⇒ `MessageExpectation`

#at_least(n, &block) ⇒ `MessageExpectation`

#at_most(n, &block) ⇒ `MessageExpectation`

#exactly(n, &block) ⇒ `MessageExpectation`

#never ⇒ `MessageExpectation`

#once(&block) ⇒ `MessageExpectation`

#ordered(&block) ⇒ `MessageExpectation`

#thrice(&block) ⇒ `MessageExpectation`

#times(&block) ⇒ `MessageExpectation` Also known as: #time

#to_s ⇒ `String` Also known as: #inspect

#twice(&block) ⇒ `MessageExpectation`

#with(*args, &block) ⇒ `MessageExpectation`