class Mocha::Expectation
Methods on expectations returned from {Mock#expects}, {Mock#stubs}, {ObjectMethods#expects} and {ObjectMethods#stubs}.
Attributes
@private
Public Class Methods
@private
# File lib/mocha/expectation.rb, line 548 def initialize(mock, expected_method_name, backtrace = nil) @mock = mock @method_matcher = MethodMatcher.new(expected_method_name.to_sym) @parameters_matcher = ParametersMatcher.new @block_matcher = BlockMatchers::OptionalBlock.new @ordering_constraints = [] @side_effects = [] @cardinality = Cardinality.new.exactly(1) @return_values = ReturnValues.new @yield_parameters = YieldParameters.new @backtrace = backtrace || caller end
Public Instance Methods
@private
# File lib/mocha/expectation.rb, line 567 def add_in_sequence_ordering_constraint(sequence) sequence.constrain_as_next_in_sequence(self) end
@private
# File lib/mocha/expectation.rb, line 562 def add_ordering_constraint(ordering_constraint) @ordering_constraints << ordering_constraint end
@private
# File lib/mocha/expectation.rb, line 572 def add_side_effect(side_effect) @side_effects << side_effect end
Modifies expectation so that the expected method must be called at least a minimum_number_of_times
.
@param [Integer] minimum_number_of_times minimum number of expected invocations. @return [Expectation] the same expectation, thereby allowing invocations of other {Expectation} methods to be chained.
@example Expected method must be called at least twice.
object = mock() object.expects(:expected_method).at_least(2) 3.times { object.expected_method } # => verify succeeds object = mock() object.expects(:expected_method).at_least(2) object.expected_method # => verify fails
# File lib/mocha/expectation.rb, line 132 def at_least(minimum_number_of_times) @cardinality.at_least(minimum_number_of_times) self end
Modifies expectation so that the expected method must be called at least once.
@return [Expectation] the same expectation, thereby allowing invocations of other {Expectation} methods to be chained.
@example Expected method must be called at least once.
object = mock() object.expects(:expected_method).at_least_once object.expected_method # => verify succeeds object = mock() object.expects(:expected_method).at_least_once # => verify fails
# File lib/mocha/expectation.rb, line 150 def at_least_once at_least(1) end
Modifies expectation so that the expected method must be called at most a maximum_number_of_times
.
@param [Integer] maximum_number_of_times maximum number of expected invocations. @return [Expectation] the same expectation, thereby allowing invocations of other {Expectation} methods to be chained.
@example Expected method must be called at most twice.
object = mock() object.expects(:expected_method).at_most(2) 2.times { object.expected_method } # => verify succeeds object = mock() object.expects(:expected_method).at_most(2) 3.times { object.expected_method } # => unexpected invocation
# File lib/mocha/expectation.rb, line 168 def at_most(maximum_number_of_times) @cardinality.at_most(maximum_number_of_times) self end
Modifies expectation so that the expected method must be called at most once.
@return [Expectation] the same expectation, thereby allowing invocations of other {Expectation} methods to be chained.
@example Expected method must be called at most once.
object = mock() object.expects(:expected_method).at_most_once object.expected_method # => verify succeeds object = mock() object.expects(:expected_method).at_most_once 2.times { object.expected_method } # => unexpected invocation
# File lib/mocha/expectation.rb, line 186 def at_most_once at_most(1) end
@private
# File lib/mocha/expectation.rb, line 582 def in_correct_order? @ordering_constraints.all?(&:allows_invocation_now?) end
Constrains the expectation so that it must be invoked at the current point in the sequence
.
To expect a sequence of invocations, write the expectations in order and add the +in_sequence(sequence)+ clause to each one.
Expectations in a sequence
can have any invocation count.
If an expectation in a sequence is stubbed, rather than expected, it can be skipped in the sequence
.
An expected method can appear in multiple sequences.
@param [Sequence] sequence sequence in which expected method should appear. @param [*Array<Sequence>] sequences more sequences in which expected method should appear. @return [Expectation] the same expectation, thereby allowing invocations of other {Expectation} methods to be chained.
@see API#sequence
@example Ensure methods are invoked in a specified 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)
# File lib/mocha/expectation.rb, line 539 def in_sequence(sequence, *sequences) sequences.unshift(sequence).each { |seq| add_in_sequence_ordering_constraint(seq) } self end
@private
# File lib/mocha/expectation.rb, line 625 def inspect address = __id__ * 2 address += 0x100000000 if address < 0 "#<Expectation:0x#{format('%x', address)} #{mocha_inspect} >" end
@private
# File lib/mocha/expectation.rb, line 597 def invocations_allowed? @cardinality.invocations_allowed? end
@private
# File lib/mocha/expectation.rb, line 607 def invoke(invocation) perform_side_effects @cardinality << invocation invocation.call(@yield_parameters, @return_values) end
@private
# File lib/mocha/expectation.rb, line 592 def match?(invocation) @method_matcher.match?(invocation.method_name) && @parameters_matcher.match?(invocation.arguments) && @block_matcher.match?(invocation.block) && in_correct_order? end
@private
# File lib/mocha/expectation.rb, line 587 def matches_method?(method_name) @method_matcher.match?(method_name) end
@private
# File lib/mocha/expectation.rb, line 642 def method_signature signature = "#{@mock.mocha_inspect}.#{@method_matcher.mocha_inspect}#{@parameters_matcher.mocha_inspect}" signature << " #{@block_matcher.mocha_inspect}" if @block_matcher.mocha_inspect signature end
@private
# File lib/mocha/expectation.rb, line 632 def mocha_inspect message = "#{@cardinality.anticipated_times}, #{@cardinality.invoked_times}: #{method_signature}" message << "; #{@ordering_constraints.map(&:mocha_inspect).join('; ')}" unless @ordering_constraints.empty? if Mocha.configuration.display_matching_invocations_on_failure? message << @cardinality.actual_invocations end message end
Modifies expectation so that when the expected method is called, it yields multiple times per invocation with the specified parameter_groups
.
If no block is provided, the method will still attempt to yield resulting in a LocalJumpError
. Note that this is what would happen if a “real” (non-mock) method implementation tried to yield to a non-existent block.
@param [*Array<Array>] parameter_groups each element of parameter_groups
should iself be an Array
representing the parameters to be passed to the block for a single yield. Any element of parameter_groups
that is not an Array
is wrapped in an Array
. @return [Expectation] the same expectation, thereby allowing invocations of other {Expectation} methods to be chained. @see then
@example When foreach
is called, the stub will invoke the block twice, the first time it passes [‘row1_col1’, ‘row1_col2’] as the parameters, and the second time it passes [‘row2_col1’, ”] as the parameters.
csv = mock() csv.expects(:foreach).with("path/to/file.csv").multiple_yields(['row1_col1', 'row1_col2'], ['row2_col1', '']) rows = [] csv.foreach { |row| rows << row } rows # => [['row1_col1', 'row1_col2'], ['row2_col1', '']]
@example Yield different groups of parameters on different invocations of the expected method. Simulating a situation where the CSV file at ‘path/to/file.csv’ has been modified between the two calls to foreach
.
csv = mock() csv.stubs(:foreach).with("path/to/file.csv").multiple_yields(['old_row1_col1', 'old_row1_col2'], ['old_row2_col1', '']).then.multiple_yields(['new_row1_col1', ''], ['new_row2_col1', 'new_row2_col2']) rows_from_first_invocation = [] rows_from_second_invocation = [] csv.foreach { |row| rows_from_first_invocation << row } # first invocation csv.foreach { |row| rows_from_second_invocation << row } # second invocation rows_from_first_invocation # => [['old_row1_col1', 'old_row1_col2'], ['old_row2_col1', '']] rows_from_second_invocation # => [['new_row1_col1', ''], ['new_row2_col1', 'new_row2_col2']]
# File lib/mocha/expectation.rb, line 326 def multiple_yields(*parameter_groups) @yield_parameters.add(*parameter_groups) self end
Modifies expectation so that the expected method must never be called.
@return [Expectation] the same expectation, thereby allowing invocations of other {Expectation} methods to be chained.
@example Expected method must never be called.
object = mock() object.expects(:expected_method).never object.expected_method # => unexpected invocation object = mock() object.expects(:expected_method).never # => verify succeeds
# File lib/mocha/expectation.rb, line 112 def never @cardinality.exactly(0) self end
Modifies expectation so that the expected method must be called exactly once.
Note that this is the default behaviour for an expectation, but you may wish to use it for clarity/emphasis.
@return [Expectation] the same expectation, thereby allowing invocations of other {Expectation} methods to be chained.
@example Expected method must be invoked exactly once.
object = mock() object.expects(:expected_method).once object.expected_method # => verify succeeds object = mock() object.expects(:expected_method).once object.expected_method object.expected_method # => unexpected invocation object = mock() object.expects(:expected_method).once # => verify fails
# File lib/mocha/expectation.rb, line 95 def once @cardinality.exactly(1) self end
@private
# File lib/mocha/expectation.rb, line 577 def perform_side_effects @side_effects.each(&:perform) end
Modifies expectation so that when the expected method is called, it raises the specified exception
with the specified message
i.e. calls +Kernel#raise(exception, message)+.
@param [Class,Exception,String,#exception] exception exception to be raised or message to be passed to RuntimeError. @param [String] message exception message. @return [Expectation] the same expectation, thereby allowing invocations of other {Expectation} methods to be chained.
@see Kernel#raise @see then
@overload def raises @overload def raises(exception) @overload def raises(exception, message)
@example Raise specified exception if expected method is invoked.
object = stub() object.stubs(:expected_method).raises(Exception, 'message') object.expected_method # => raises exception of class Exception and with message 'message'
@example Raise custom exception with extra constructor parameters by passing in an instance of the exception.
object = stub() object.stubs(:expected_method).raises(MyException.new('message', 1, 2, 3)) object.expected_method # => raises the specified instance of MyException
@example Raise different exceptions on consecutive invocations of the expected method.
object = stub() object.stubs(:expected_method).raises(Exception1).then.raises(Exception2) object.expected_method # => raises exception of class Exception1 object.expected_method # => raises exception of class Exception2
@example Raise an exception on first invocation of expected method and then return values on subsequent invocations.
object = stub() object.stubs(:expected_method).raises(Exception).then.returns(2, 3) object.expected_method # => raises exception of class Exception1 object.expected_method # => 2 object.expected_method # => 3
# File lib/mocha/expectation.rb, line 413 def raises(exception = RuntimeError, message = nil) @return_values += ReturnValues.new(ExceptionRaiser.new(exception, message)) self end
Modifies expectation so that when the expected method is called, it returns the specified value
.
@return [Expectation] the same expectation, thereby allowing invocations of other {Expectation} methods to be chained. @see then
@overload def returns(value)
@param [Object] value value to return on invocation of expected method.
@overload def returns(*values)
@param [*Array] values values to return on consecutive invocations of expected method.
@example Return the same value on every invocation.
object = mock() object.stubs(:stubbed_method).returns('result') object.stubbed_method # => 'result' object.stubbed_method # => 'result'
@example Return a different value on consecutive invocations.
object = mock() object.stubs(:stubbed_method).returns(1, 2) object.stubbed_method # => 1 object.stubbed_method # => 2
@example Alternative way to return a different value on consecutive invocations.
object = mock() object.stubs(:expected_method).returns(1, 2).then.returns(3) object.expected_method # => 1 object.expected_method # => 2 object.expected_method # => 3
@example May be called in conjunction with {#raises} on the same expectation.
object = mock() object.stubs(:expected_method).returns(1, 2).then.raises(Exception) object.expected_method # => 1 object.expected_method # => 2 object.expected_method # => raises exception of class Exception1
@example Note that in Ruby a method returning multiple values is exactly equivalent to a method returning an Array
of those values.
object = mock() object.stubs(:expected_method).returns([1, 2]) x, y = object.expected_method x # => 1 y # => 2
# File lib/mocha/expectation.rb, line 373 def returns(*values) @return_values += ReturnValues.build(*values) self end
@private
# File lib/mocha/expectation.rb, line 602 def satisfied? @cardinality.satisfied? end
@overload def then
Used as syntactic sugar to improve readability. It has no effect on state of the expectation.
@overload def then(state)
Used to change the +state_machine+ to the specified state when the expected invocation occurs. @param [StateMachine::State] state state_machine.is(state_name) provides a mechanism to change the +state_machine+ into the state specified by +state_name+ when the expected method is invoked. @see API#states @see StateMachine @see #when
@return [Expectation] the same expectation, thereby allowing invocations of other {Expectation} methods to be chained.
@example Using {#then} as syntactic sugar when specifying values to be returned and exceptions to be raised on consecutive invocations of the expected method.
object = mock() object.stubs(:expected_method).returns(1, 2).then.raises(Exception).then.returns(4) object.expected_method # => 1 object.expected_method # => 2 object.expected_method # => raises exception of class Exception object.expected_method # => 4
@example Using {#then} to change the state
of a state_machine
on the invocation of an expected method.
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'))
# File lib/mocha/expectation.rb, line 487 def then(state = nil) add_side_effect(ChangeStateSideEffect.new(state)) if state self end
Modifies expectation so that when the expected method is called, it throws the specified tag
with the specific return value object
i.e. calls +Kernel#throw(tag, object)+.
@param [Symbol,String] tag tag to throw to transfer control to the active catch block. @param [Object] object return value for the catch block. @return [Expectation] the same expectation, thereby allowing invocations of other {Expectation} methods to be chained.
@see Kernel#throw @see then
@overload def throw(tag) @overload def throw(tag, object)
@example Throw tag when expected method is invoked.
object = stub() object.stubs(:expected_method).throws(:done) object.expected_method # => throws tag :done
@example Throw tag with return value object
c.f. +Kernel#throw+.
object = stub() object.stubs(:expected_method).throws(:done, 'result') object.expected_method # => throws tag :done and causes catch block to return 'result'
@example Throw different tags on consecutive invocations of the expected method.
object = stub() object.stubs(:expected_method).throws(:done).then.throws(:continue) object.expected_method # => throws :done object.expected_method # => throws :continue
@example Throw tag on first invocation of expected method and then return values for subsequent invocations.
object = stub() object.stubs(:expected_method).throws(:done).then.returns(2, 3) object.expected_method # => throws :done object.expected_method # => 2 object.expected_method # => 3
# File lib/mocha/expectation.rb, line 452 def throws(tag, object = nil) @return_values += ReturnValues.new(Thrower.new(tag, object)) self end
Modifies expectation so that the number of calls to the expected method must be within a specific range
.
@param [Range,Integer] range specifies the allowable range in the number of expected invocations. @return [Expectation] the same expectation, thereby allowing invocations of other {Expectation} methods to be chained.
@example Specifying a specific number of expected invocations.
object = mock() object.expects(:expected_method).times(3) 3.times { object.expected_method } # => verify succeeds object = mock() object.expects(:expected_method).times(3) 2.times { object.expected_method } # => verify fails
@example Specifying a range in the number of expected invocations.
object = mock() object.expects(:expected_method).times(2..4) 3.times { object.expected_method } # => verify succeeds object = mock() object.expects(:expected_method).times(2..4) object.expected_method # => verify fails
# File lib/mocha/expectation.rb, line 44 def times(range) @cardinality.times(range) self end
Modifies expectation so that the expected method must be called exactly twice.
@return [Expectation] the same expectation, thereby allowing invocations of other {Expectation} methods to be chained.
@example Expected method must be invoked exactly twice.
object = mock() object.expects(:expected_method).twice object.expected_method object.expected_method # => verify succeeds object = mock() object.expects(:expected_method).twice object.expected_method object.expected_method object.expected_method # => unexpected invocation object = mock() object.expects(:expected_method).twice object.expected_method # => verify fails
# File lib/mocha/expectation.rb, line 70 def twice @cardinality.exactly(2) self end
@private
# File lib/mocha/expectation.rb, line 620 def used? @cardinality.used? end
@private
# File lib/mocha/expectation.rb, line 614 def verified?(assertion_counter = nil) assertion_counter.increment if assertion_counter && @cardinality.needs_verifying? @cardinality.verified? end
Constrains the expectation to occur only when the state_machine
is in the state specified by state_predicate
.
@param [StateMachine::StatePredicate] state_predicate +state_machine.is(state_name)+ provides a mechanism to determine whether the state_machine
is in the state specified by state_predicate
when the expected method is invoked. @return [Expectation] the same expectation, thereby allowing invocations of other {Expectation} methods to be chained.
@see API#states
@see StateMachine
@see then
@example Using {#when} to only allow invocation of methods when “power” state machine is in the “on” state.
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'))
# File lib/mocha/expectation.rb, line 511 def when(state_predicate) add_ordering_constraint(InStateOrderingConstraint.new(state_predicate)) self end
Modifies expectation so that the expected method must be called with expected_parameters
.
May be used with parameter matchers in {ParameterMatchers}.
@param [*Array] expected_parameters parameters expected. @yield optional block specifying custom matching. @yieldparam [*Array] actual_parameters parameters with which expected method was invoked. @yieldreturn [Boolean] true
if actual_parameters
are acceptable. @return [Expectation] the same expectation, thereby allowing invocations of other {Expectation} methods to be chained.
@example Expected method must be called with expected parameters.
object = mock() object.expects(:expected_method).with(:param1, :param2) object.expected_method(:param1, :param2) # => verify succeeds object = mock() object.expects(:expected_method).with(:param1, :param2) object.expected_method(:param3) # => verify fails
@example Expected method must be called with a value divisible by 4.
object = mock() object.expects(:expected_method).with() { |value| value % 4 == 0 } object.expected_method(16) # => verify succeeds object = mock() object.expects(:expected_method).with() { |value| value % 4 == 0 } object.expected_method(17) # => verify fails
# File lib/mocha/expectation.rb, line 221 def with(*expected_parameters, &matching_block) @parameters_matcher = ParametersMatcher.new(expected_parameters, &matching_block) self end
Modifies expectation so that the expected method must be called with a block.
@return [Expectation] the same expectation, thereby allowing invocations of other {Expectation} methods to be chained.
@example Expected method must be called with a block.
object = mock() object.expects(:expected_method).with_block_given object.expected_method { 1 + 1 } # => verify succeeds object = mock() object.expects(:expected_method).with_block_given object.expected_method # => verify fails
# File lib/mocha/expectation.rb, line 240 def with_block_given @block_matcher = BlockMatchers::BlockGiven.new self end
Modifies expectation so that the expected method must be called without a block.
@return [Expectation] the same expectation, thereby allowing invocations of other {Expectation} methods to be chained.
@example Expected method must be called without a block.
object = mock() object.expects(:expected_method).with_no_block_given object.expected_method # => verify succeeds object = mock() object.expects(:expected_method).with_block_given object.expected_method { 1 + 1 } # => verify fails
# File lib/mocha/expectation.rb, line 259 def with_no_block_given @block_matcher = BlockMatchers::NoBlockGiven.new self end
Modifies expectation so that when the expected method is called, it yields to the block with the specified parameters
.
If no parameters
are specified, it yields to the block without any parameters.
If no block is provided, the method will still attempt to yield resulting in a LocalJumpError
. Note that this is what would happen if a “real” (non-mock) method implementation tried to yield to a non-existent block.
May be called multiple times on the same expectation for consecutive invocations.
@param [*Array] parameters parameters to be yielded. @return [Expectation] the same expectation, thereby allowing invocations of other {Expectation} methods to be chained. @see then
@example Yield when expected method is invoked.
benchmark = mock() benchmark.expects(:measure).yields yielded = false benchmark.measure { yielded = true } yielded # => true
@example Yield parameters when expected method is invoked.
fibonacci = mock() fibonacci.expects(:next_pair).yields(0, 1) sum = 0 fibonacci.next_pair { |first, second| sum = first + second } sum # => 1
@example Yield different parameters on different invocations of the expected method.
fibonacci = mock() fibonacci.expects(:next_pair).yields(0, 1).then.yields(1, 1) sum = 0 fibonacci.next_pair { |first, second| sum = first + second } sum # => 1 fibonacci.next_pair { |first, second| sum = first + second } sum # => 2
# File lib/mocha/expectation.rb, line 298 def yields(*parameters) multiple_yields(parameters) end