RSpec matcher for matching transitions of Pushdown::States
Create a new matcher that expects a transition to occur.
# File lib/pushdown/spec_helpers.rb, line 25
def initialize
@expected_type = nil
@target_state = nil
@callback = nil
@additional_expectations = []
@state = nil
@result = nil
@failure_description = nil
endRSpec matcher API – return a message describing an expectation failure.
# File lib/pushdown/spec_helpers.rb, line 59
def failure_message
return "%p: %s" % [ self.state, self.describe_failure ]
endRSpec matcher API – return a message describing an expectation being met when the matcher was used in a negated context.
# File lib/pushdown/spec_helpers.rb, line 66
def failure_message_when_negated
return "%p: %s" % [ self.state, self.describe_negated_failure ]
endRSpec matcher API – returns true if all expectations are met after calling
state.¶ ↑# File lib/pushdown/spec_helpers.rb, line 47
def matches?( state )
@state = state
return self.update_ran_without_error? &&
self.update_returned_transition? &&
self.correct_transition_type? &&
self.correct_target_state? &&
self.matches_additional_expectations?
endSpecify that the operation that should cause the transition is the on_event callback.
# File lib/pushdown/spec_helpers.rb, line 105
def on_an_event( event, *args )
raise ScriptError, "can't specify more than one callback" if self.callback
@callback = [ :on_event, event, *args ]
return self
endSpecify that the operation that should cause the transition is the update callback. This is the default.
# File lib/pushdown/spec_helpers.rb, line 97
def on_update
raise ScriptError, "can't specify more than one callback" if self.callback
@callback = [ :update ]
return self
endAdd an additional expectation that the state that is transitioned to be of the given state_name. This only applies to transitions that take a target state type. Expecting a particular state_name in transitions which do not take a state is undefined behavior.
# File lib/pushdown/spec_helpers.rb, line 88
def to_state( state_name )
@target_state = state_name
return self
endAdd an additional expectation that the transition that occurs be of the specified transition_type.
# File lib/pushdown/spec_helpers.rb, line 77
def via_transition_type( transition_type )
@expected_type = transition_type
return self
endReturns true if a target state was specified and the transition which occurred was to that state.
# File lib/pushdown/spec_helpers.rb, line 164
def correct_target_state?
state_name = self.target_state or return true
case self.result
when Pushdown::Transition
return self.result.respond_to?( :state_class ) &&
self.result.state_class.type_name == state_name
when Symbol
self.state.class.transitions[ self.result ][ 1 ] == state_name
end
endReturns true if a transition type was specified and the transition which occurred was of that type.
# File lib/pushdown/spec_helpers.rb, line 148
def correct_transition_type?
type = self.expected_type or return true
case self.result
when Pushdown::Transition
self.result.type_name == type
when Symbol
self.state.class.transitions[ self.result ].first == type
else
raise "unexpected transition result type %p" % [ self.result ]
end
endReturn an Array of descriptions of the members that were expected to be included in the state body, if any were specified. If none were specified, returns an empty Array.
# File lib/pushdown/spec_helpers.rb, line 233
def describe_additional_expectations
return self.additional_expectations.map( &:description )
endBuild an appropriate failure messages for the matcher.
# File lib/pushdown/spec_helpers.rb, line 178
def describe_failure
desc = String.new( "expected to transition" )
desc << " via %s" % [ self.expected_type ] if self.expected_type
desc << " to %s" % [ self.target_state ] if self.target_state
if self.callback
methname, *args = self.callback
desc << " when #%s is called" % [ methname ]
desc << " with %s" % [ args.map(&:inspect).join(', ') ] if !args.empty?
end
desc << ', but '
case self.result
when Exception
err = self.result
desc << "got %p: %s" % [ err.class, err.message ]
when Symbol
transition = self.state.class.transitions[ self.result ]
if transition
desc << "it returned a %s transition " % [ transition.first ]
desc << "to %s " % [ transition[1] ] if transition[1]
desc << " instead"
else
desc << "it returned an unmapped Symbol (%p)" % [ self.result ]
end
when Pushdown::Transition
desc << "it returned a %s transition" % [ self.result.type_name ]
desc << " to %s" % [ self.result.state_class.type_name ] if
self.result.respond_to?( :state_class )
desc << " instead"
else
desc << "it did not (returned: %p)" % [ self.result ]
end
return desc
endBuild an appropriate failure message for the matcher.
# File lib/pushdown/spec_helpers.rb, line 219
def describe_negated_failure
desc = String.new( "expected not to transition" )
desc << " via %s" % [ self.expected_type ] if self.expected_type
desc << " to %s" % [ self.target_state ] if self.target_state
desc << ', but it did.'
return desc
endCheck that any additional matchers registered via the .and mutator also match the parsed state body.
# File lib/pushdown/spec_helpers.rb, line 240
def matches_additional_expectations?
return self.additional_expectations.all? do |matcher|
matcher.matches?( self.parsed_state_body ) or
fail_with( matcher.failure_message )
end
endCall the state's update callback and record the result, then return true if no exception was raised.
# File lib/pushdown/spec_helpers.rb, line 119
def update_ran_without_error?
operation = self.callback || DEFAULT_CALLBACK
@result = begin
self.state.public_send( *operation )
rescue => err
err
end
return !@result.is_a?( Exception )
endReturns true if the result of calling update was a Transition or a Symbol that corresponds with a valid transition.
# File lib/pushdown/spec_helpers.rb, line 134
def update_returned_transition?
case self.result
when Pushdown::Transition
return true
when Symbol
return self.state.class.transitions.include?( self.result )
else
return false
end
end