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module RSpec
# rspec-expecations provides a number of useful Matchers we use to compose
# expectations. A Matcher is any object that responds to the following
# methods:
#
# matches?(actual)
# failure_message_for_should
#
# These methods are also part of the matcher protocol, but are optional:
#
# does_not_match?(actual)
# failure_message_for_should_not
# description #optional
#
# == 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 Matchers
#
# When you find that none of the stock Expectation Matchers provide a natural
# feeling expectation, you can very easily write your own using RSpec's matcher
# DSL or writing one from scratch.
#
# === Matcher DSL
#
# 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")
#
# You can create such a matcher like so:
#
# RSpec::Matchers.define :be_in_zone do |zone|
# match do |player|
# player.in_zone?(zone)
# end
# end
#
# This will generate a <tt>be_in_zone</tt> method that returns a matcher
# with logical default messages for failures. You can override the failure
# messages and the generated description as follows:
#
# RSpec::Matchers.define :be_in_zone do |zone|
# match do |player|
# player.in_zone?(zone)
# end
# failure_message_for_should do |player|
# # generate and return the appropriate string.
# end
# failure_message_for_should_not do |player|
# # generate and return the appropriate string.
# end
# description do
# # generate and return the appropriate string.
# end
# docstring_for_should do
# # generate and return the appropriate string.
# end
# docstring_for_should_not do
# # generate and return the appropriate string.
# end
# end
#
# Each of the message-generation methods has access to the block arguments
# passed to the <tt>create</tt> method (in this case, <tt>zone</tt>). The
# failure message methods (<tt>failure_message_for_should</tt> and
# <tt>failure_message_for_should_not</tt>) are passed the actual value (the
# receiver of <tt>should</tt> or <tt>should_not</tt>).
#
# === Custom Matcher from scratch
#
# You could also write a custom matcher from scratch, as follows:
#
# class BeInZone
# def initialize(expected)
# @expected = expected
# end
# def matches?(target)
# @target = target
# @target.current_zone.eql?(Zone.new(@expected))
# end
# def failure_message_for_should
# "expected #{@target.inspect} to be in Zone #{@expected}"
# end
# def failure_message_for_should_not
# "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):
#
# RSpec::Runner.configure do |config|
# config.include(CustomGameMatchers)
# end
#
module Matchers
# Include Matchers for other test frameworks.
# Note that MiniTest _must_ come before TU because on ruby 1.9,
# T::U::TC is a subclass of MT::U::TC and a 1.9 bug can lead
# to infinite recursion from the `super` call in our method_missing
# hook. See this gist for more info:
# https://gist.github.com/845896
if defined?(MiniTest::Unit::TestCase)
MiniTest::Unit::TestCase.send(:include, self)
end
if defined?(Test::Unit::TestCase)
Test::Unit::TestCase.send(:include, self)
end
end
end
require 'rspec/matchers/extensions/instance_exec'
require 'rspec/matchers/pretty'
require 'rspec/matchers/matcher'
require 'rspec/matchers/operator_matcher'
require 'rspec/matchers/be'
require 'rspec/matchers/be_close'
require 'rspec/matchers/be_instance_of'
require 'rspec/matchers/be_kind_of'
require 'rspec/matchers/be_within'
require 'rspec/matchers/block_aliases'
require 'rspec/matchers/change'
require 'rspec/matchers/cover' if (1..2).respond_to? :cover?
require 'rspec/matchers/eq'
require 'rspec/matchers/eql'
require 'rspec/matchers/equal'
require 'rspec/matchers/errors'
require 'rspec/matchers/exist'
require 'rspec/matchers/generated_descriptions'
require 'rspec/matchers/has'
require 'rspec/matchers/have'
require 'rspec/matchers/include'
require 'rspec/matchers/match'
require 'rspec/matchers/match_array'
require 'rspec/matchers/method_missing'
require 'rspec/matchers/raise_error'
require 'rspec/matchers/respond_to'
require 'rspec/matchers/satisfy'
require 'rspec/matchers/throw_symbol'
require 'rspec/matchers/compatibility'
require 'rspec/matchers/dsl'
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