Remarkable

This is the core package of Remarkable. It provides a DSL for creating matchers with I18n support, decouples messages from matchers logic, add rspec extra features, create macros automatically and allow those macros to be configurable wth blocks.

Macros

Each matcher in Remarkable is also available as a macro. So this matcher:

it { should validate_numericality_of(:age, :greater_than => 18, :only_integer => true) }
it { should validate_numericality_of(:age).greater_than(18).only_integer }

Can also be written as:

should_validate_numericality_of :age, :greater_than => 18, :only_integer => true

Which can be also written as:

should_validate_numericality_of :age do |m|
  m.only_integer
  m.greater_than 18
  # Or: m.greater_than = 18
end

Choose your style!

Disabled Macros

Remarkable adds the possibility to disable macros. So as you could do:

xit { should validate_presence_of(:name) }

You can also do:

xshould_validate_presence_of :name

And it will show in your specs output:

"Example disabled: require name to be set"

Pending macros

In Rspec you can mark some examples as pending:

it "should have one manager" do
  pending("create managers resource")
end

it "should validate associated manager" do
  pending("create managers resource")
end

To allow this to work with macros, we created the pending group:

pending "create managers resource" do
  should_have_one :manager
  should_validate_associated :manager
end

This outputs the same as above.

I18n

All matchers come with I18n support. You can find an example locale file under the locale folder of each project.

To change the locale, you have first to add your locale file:

Remarkable.add_locale 'path/to/my_locale.yml'

And then:

Remarkable.locale = :my_locale

Internationalization is powered by the I18n gem. If you are using it with Rails, it will use the built in gem, otherwise you will have to install the gem by hand:

gem sources -a http://gems.github.com
sudo gem install svenfuchs-i18n

Creating you own matcher

Create a new matcher is easy. Let’s create validate_inclusion_of matcher for ActiveRecord as an example. A first matcher version would be:

module Remarkable

module ActiveRecord
  module Matchers
    class ValidateInclusionOfMatcher < Remarkable::ActiveRecord::Base
      arguments :attribute
      assertion :is_valid?

      optional :in
      optional :allow_blank, :allow_nil, :default => true

      protected

        def is_valid?
          @options[:in].each do |value|
            @subject.send(:"#{@attribute}=", value)
            return false, :value => value unless @subject.valid?
          end
          true
        end
    end

    def validate_inclusion_of(*args)
      ValidateInclusionOfMatcher.new(*args).spec(self)
    end
  end
end

end

This creates a matcher which requires one attribute and has :in, :allow_blank and :allow_nil as options. So you can call the matcher in the following way:

should_validate_inclusion_of :size, :in => %w(S M L XL)
should_validate_inclusion_of :size, :in => %w(S M L XL), :allow_blank => true

it { should validate_inclusion_of(:size, :in => %w(S M L XL)).allow_nil(true) }
it { should validate_inclusion_of(:size, :in => %w(S M L XL)).allow_nil }

it { should validate_inclusion_of(:size, :in => %w(S M L XL)) }
it { should validate_inclusion_of(:size, :in => %w(S M L XL), :allow_nil => true) }

The assertions methods (in this case, :is_valid?) makes the matcher pass when it returns true and fail when returns false.

As you noticed, the matcher doesn’t have any message on it. You add them on I18n file. A file for this example would be:

remarkable:
  active_record:
    validate_inclusion_of:
      description: "validate inclusion of {{attribute}}"
      expectations:
        is_valid: "to be valid when {{attribute}} is {{value}}"
      optionals:
        in:
          positive: "in {{inspect}}"
        allow_nil:
          positive: "allowing nil values"
          negative: "not allowing nil values"
        allow_blank:
          positive: "allowing blank values"
          negative: "allowing blank values"

The optionals are just added to the description message when they are supplied. Look some description messages examples:

should_validate_inclusion_of :size, :in => %w(S M L XL)
#=> should validate inclusion of size in ["S", "M", "L", "XL"]

should_validate_inclusion_of :size, :in => %w(S M L XL), :allow_nil => true
#=> should validate inclusion of size in ["S", "M", "L", "XL"] and allowing nil values

should_validate_inclusion_of :size, :in => %w(S M L XL), :allow_nil => false
#=> should validate inclusion of size in ["S", "M", "L", "XL"] and not allowing nil values

Please notice that the arguments are available as interpolation option, as well as the optionals.

The expectations message are set whenever one of the assertions returns false. In this case, whenever the assertion fails, we are also returning a hash, with the value that failed:

return false, :value => value

This will tell remarkable to make value as interpolation option too.

Whenever you create all your matchers, you tell remarkable to add them to the desired rspec example group:

Remarkable.include_matchers!(Remarkable::ActiveRecord, Spec::Example::ExampleGroup)

Working with collections

Finally, Remarkable also makes easy to deal with collections. The same matcher could be easily extended to accept a collection of attributes instead of just one:

should_validate_inclusion_of :first_size, :second_size, :in => %w(S M L XL)

For this we have just those two lines:

arguments :attribute
assertion :is_valid?

For:

arguments :collection => :attributes, :as => :attribute
collection_assertion :is_valid?

This means that the collection will be kept in the @attributes instance variable and for each value in the collection, it will run the :is_valid? assertion.

Whenever running the assertion, it will also set the @attribute (in singular) variable. In your I18n files, you just need to change your description:

validate_inclusion_of:
  description: "validate inclusion of {{attributes}}"

And this will output:

should_validate_inclusion_of :first_size, :second_size, :in => %w(S M L XL)
#=> should validate inclusion of first size and second size in ["S", "M", "L", "XL"]

More

This is just an overview of the API. You can add extra options to interpolation by overwriting the interpolation_options methods, you can add callbacks after initialize your matcher or before asserting and much more!