+++ /dev/null
-module Spec
- module Matchers
-
- #Based on patch from Wilson Bilkovich
- class Change #:nodoc:
- def initialize(receiver=nil, message=nil, &block)
- @receiver = receiver
- @message = message
- @block = block
- end
-
- def matches?(target, &block)
- if block
- raise MatcherError.new(<<-EOF
-block passed to should or should_not change must use {} instead of do/end
-EOF
-)
- end
- @target = target
- execute_change
- return false if @from && (@from != @before)
- return false if @to && (@to != @after)
- return (@before + @amount == @after) if @amount
- return ((@after - @before) >= @minimum) if @minimum
- return ((@after - @before) <= @maximum) if @maximum
- return @before != @after
- end
-
- def execute_change
- @before = @block.nil? ? @receiver.send(@message) : @block.call
- @target.call
- @after = @block.nil? ? @receiver.send(@message) : @block.call
- end
-
- def failure_message
- if @to
- "#{result} should have been changed to #{@to.inspect}, but is now #{@after.inspect}"
- elsif @from
- "#{result} should have initially been #{@from.inspect}, but was #{@before.inspect}"
- elsif @amount
- "#{result} should have been changed by #{@amount.inspect}, but was changed by #{actual_delta.inspect}"
- elsif @minimum
- "#{result} should have been changed by at least #{@minimum.inspect}, but was changed by #{actual_delta.inspect}"
- elsif @maximum
- "#{result} should have been changed by at most #{@maximum.inspect}, but was changed by #{actual_delta.inspect}"
- else
- "#{result} should have changed, but is still #{@before.inspect}"
- end
- end
-
- def result
- @message || "result"
- end
-
- def actual_delta
- @after - @before
- end
-
- def negative_failure_message
- "#{result} should not have changed, but did change from #{@before.inspect} to #{@after.inspect}"
- end
-
- def by(amount)
- @amount = amount
- self
- end
-
- def by_at_least(minimum)
- @minimum = minimum
- self
- end
-
- def by_at_most(maximum)
- @maximum = maximum
- self
- end
-
- def to(to)
- @to = to
- self
- end
-
- def from (from)
- @from = from
- self
- end
- end
-
- # :call-seq:
- # should change(receiver, message, &block)
- # should change(receiver, message, &block).by(value)
- # should change(receiver, message, &block).from(old).to(new)
- # should_not change(receiver, message, &block)
- #
- # Allows you to specify that a Proc will cause some value to change.
- #
- # == Examples
- #
- # lambda {
- # team.add_player(player)
- # }.should change(roster, :count)
- #
- # lambda {
- # team.add_player(player)
- # }.should change(roster, :count).by(1)
- #
- # lambda {
- # team.add_player(player)
- # }.should change(roster, :count).by_at_least(1)
- #
- # lambda {
- # team.add_player(player)
- # }.should change(roster, :count).by_at_most(1)
- #
- # string = "string"
- # lambda {
- # string.reverse
- # }.should change { string }.from("string").to("gnirts")
- #
- # lambda {
- # person.happy_birthday
- # }.should change(person, :birthday).from(32).to(33)
- #
- # lambda {
- # employee.develop_great_new_social_networking_app
- # }.should change(employee, :title).from("Mail Clerk").to("CEO")
- #
- # Evaluates +receiver.message+ or +block+ before and
- # after it evaluates the c object (generated by the lambdas in the examples above).
- #
- # Then compares the values before and after the +receiver.message+ and
- # evaluates the difference compared to the expected difference.
- #
- # == Warning
- # +should_not+ +change+ only supports the form with no subsequent calls to
- # +by+, +by_at_least+, +by_at_most+, +to+ or +from+.
- #
- # blocks passed to +should+ +change+ and +should_not+ +change+
- # must use the <tt>{}</tt> form (<tt>do/end</tt> is not supported)
- def change(target=nil, message=nil, &block)
- Matchers::Change.new(target, message, &block)
- end
- end
-end