matchy¶ ↑

• github.com/jeremymcanally/matchy

Hate writing assertions? Need a little behavior-driven love in your tests? Then matchy is for you.

• Get the beauty of RSpec without all the overhead

• Create your own matchers with ease

• Get BDD on your objects

  x = 13 * 4
  x.should == 42
  
  y = "hello"
  y.length.should_not be(4)
  

• Use familiar syntax to specify things

  # RSpec
  "my string".should =~ /string/
  lambda { raise "FAIL" }.should raise_error
  
  # matchy
  "my string".should =~ /string/
  lambda { raise "FAIL" }.should raise_error
  

• Most of familiar RSpec Matchers are built in

  # raise_error matcher
  lambda {raise}.should raise_error                                  #pass
  lambda {raise MyCustomError.new}.should raise_error(MyCustomError) #pass
  lambda {raise "message"}.should raise_error("message")             #pass
  lambda {raise "message"}.should raise_error(/essa/)                #pass
  
  # change matcher
  lambda {@var+=1}.should change {@var}
  # passes
  lambda { }.should change {@var}
  # fails
  @var = 1
  lambda {@var+=1}.should change {@var}.from(1).to(2)
  # passes
  
  # be_something matcher
  @obj.should be_something
  # passes if @obj.something? is true
  
  * a lot more ...

• Create your own custom matchers

  # maybe in your test helper
  class Test::Unit::TestCase
    custom_matcher :be_nil do |receiver, matcher, args|
      receiver.nil?
    end
  
    # also you can set positive (should) and negative (should not) failure messages
    custom_matcher :be_nil do |receiver, matcher, args|
      matcher.positive_failure_message = "Expected #{receiver} to be nil but it wasn't"
      matcher.negative_failure_message = "Expected #{receiver} not to be nil but it was"
      receiver.nil?
    end
  end
  
  # your actual test
  class NilTest < Test::Unit::TestCase
    def test_nil_stuff
      nil.should be_nil       # pass
      nil.should_not be_nil   # fail
      'foo'.should_not be_nil # pass
      'foo'.should be_nil     # fail
    end
  end
  
  # Matchers can accept arguments
  class Test::Unit::TestCase
    custom_matcher :have_error_on do |receiver, matcher, args|
      attribute = args[0]
  
      receiver.valid?
      receiver.errors.on(attribute).should_not == nil
    end
  end
  
  class ArgumentTest < Test::Unit::TestCase
    class Item < ActiveRecord::Base
      validate_presence_of :title
    end
  
    def test_arguments
      item = Item.new
      item.should have_error_on(:title)     # pass
      item.title = 'Foo'
      item.should_not have_error_on(:title) # pass
    end
  end
  
  # Even more advanced, you can have messages on matchers
  class Test::Unit::TestCase
    custom_matcher :have do |receiver, matcher, args|  
      count = args[0]
      something = matcher.chained_messages[0].name
      actual = receiver.send(something).size
      matcher.positive_failure_message = "Expected #{receiver} to have #{actual} #{something}, but found #{count} "
      actual == count
    end
  end
  
  class MoreAdvancedTest < Test::Unit::TestCase
    class Item
      def tags
        %w(foo bar baz)
      end
    end
  
    def test_item_has_tags
      item = Item.new
      item.should have(3).tags # pass
      item.should have(2).tags # fail
    end
  end
  

• Test::Unit (you got it)

$ gem sources -a http://gems.github.com
$ sudo gem install jnunemaker-matchy

(The MIT License)

Copyright © 2008 Jeremy McAnally

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the ‘Software’), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED ‘AS IS’, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.