openstreetmap-website/vendor/gems/rspec-1.1.2/lib/spec/matchers.rb
2008-01-22 16:39:09 +00:00

156 lines
4.9 KiB
Ruby

require 'spec/matchers/simple_matcher'
require 'spec/matchers/be'
require 'spec/matchers/be_close'
require 'spec/matchers/change'
require 'spec/matchers/eql'
require 'spec/matchers/equal'
require 'spec/matchers/exist'
require 'spec/matchers/has'
require 'spec/matchers/have'
require 'spec/matchers/include'
require 'spec/matchers/match'
require 'spec/matchers/raise_error'
require 'spec/matchers/respond_to'
require 'spec/matchers/satisfy'
require 'spec/matchers/throw_symbol'
require 'spec/matchers/operator_matcher'
module Spec
# RSpec ships with a number of useful Expression Matchers. An Expression Matcher
# is any object that responds to the following methods:
#
# matches?(actual)
# failure_message
# negative_failure_message #optional
# description #optional
#
# See Spec::Expectations to learn how to use these as Expectation Matchers.
# See Spec::Mocks to learn how to use them as Mock Argument Constraints.
#
# == Predicates
#
# In addition to those Expression Matchers that are defined explicitly, RSpec will
# create custom Matchers on the fly for any arbitrary predicate, giving your specs
# a much more natural language feel.
#
# A Ruby predicate is a method that ends with a "?" and returns true or false.
# Common examples are +empty?+, +nil?+, and +instance_of?+.
#
# All you need to do is write +should be_+ followed by the predicate without
# the question mark, and RSpec will figure it out from there. For example:
#
# [].should be_empty => [].empty? #passes
# [].should_not be_empty => [].empty? #fails
#
# In addtion to prefixing the predicate matchers with "be_", you can also use "be_a_"
# and "be_an_", making your specs read much more naturally:
#
# "a string".should be_an_instance_of(String) =>"a string".instance_of?(String) #passes
#
# 3.should be_a_kind_of(Fixnum) => 3.kind_of?(Numeric) #passes
# 3.should be_a_kind_of(Numeric) => 3.kind_of?(Numeric) #passes
# 3.should be_an_instance_of(Fixnum) => 3.instance_of?(Fixnum) #passes
# 3.should_not be_instance_of(Numeric) => 3.instance_of?(Numeric) #fails
#
# RSpec will also create custom matchers for predicates like +has_key?+. To
# use this feature, just state that the object should have_key(:key) and RSpec will
# call has_key?(:key) on the target. For example:
#
# {:a => "A"}.should have_key(:a) => {:a => "A"}.has_key?(:a) #passes
# {:a => "A"}.should have_key(:b) => {:a => "A"}.has_key?(:b) #fails
#
# You can use this feature to invoke any predicate that begins with "has_", whether it is
# part of the Ruby libraries (like +Hash#has_key?+) or a method you wrote on your own class.
#
# == Custom Expectation Matchers
#
# When you find that none of the stock Expectation Matchers provide a natural
# feeling expectation, you can very easily write your own.
#
# For example, imagine that you are writing a game in which players can
# be in various zones on a virtual board. To specify that bob should
# be in zone 4, you could say:
#
# bob.current_zone.should eql(Zone.new("4"))
#
# But you might find it more expressive to say:
#
# bob.should be_in_zone("4")
#
# and/or
#
# bob.should_not be_in_zone("3")
#
# To do this, you would need to write a class like this:
#
# class BeInZone
# def initialize(expected)
# @expected = expected
# end
# def matches?(target)
# @target = target
# @target.current_zone.eql?(Zone.new(@expected))
# end
# def failure_message
# "expected #{@target.inspect} to be in Zone #{@expected}"
# end
# def negative_failure_message
# "expected #{@target.inspect} not to be in Zone #{@expected}"
# end
# end
#
# ... and a method like this:
#
# def be_in_zone(expected)
# BeInZone.new(expected)
# end
#
# And then expose the method to your specs. This is normally done
# by including the method and the class in a module, which is then
# included in your spec:
#
# module CustomGameMatchers
# class BeInZone
# ...
# end
#
# def be_in_zone(expected)
# ...
# end
# end
#
# describe "Player behaviour" do
# include CustomGameMatchers
# ...
# end
#
# or you can include in globally in a spec_helper.rb file <tt>require</tt>d
# from your spec file(s):
#
# Spec::Runner.configure do |config|
# config.include(CustomGameMatchers)
# end
#
module Matchers
module ModuleMethods
attr_accessor :generated_description
def clear_generated_description
self.generated_description = nil
end
end
extend ModuleMethods
def method_missing(sym, *args, &block) # :nodoc:
return Matchers::Be.new(sym, *args) if sym.starts_with?("be_")
return Matchers::Has.new(sym, *args) if sym.starts_with?("have_")
super
end
class MatcherError < StandardError
end
end
end