Shoulda Matchers

Shoulda Matchers provides RSpec- and Minitest-compatible one-liners that test common Rails functionality. These tests would otherwise be much longer, more complex, and error-prone.

View the official documentation for the latest version (3.1.3).

ActiveModel matchers

allow_mass_assignment_of tests usage of Rails 3's attr_accessible and attr_protected macros.
allow_value tests that an attribute is valid or invalid if set to one or more values. (Aliased as #allow_values.)
have_secure_password tests usage of has_secure_password.
validate_absence_of tests usage of validates_absence_of.
validate_acceptance_of tests usage of validates_acceptance_of.
validate_confirmation_of tests usage of validates_confirmation_of.
validate_exclusion_of tests usage of validates_exclusion_of.
validate_inclusion_of tests usage of validates_inclusion_of.
validate_length_of tests usage of validates_length_of.
validate_numericality_of tests usage of validates_numericality_of.
validate_presence_of tests usage of validates_presence_of.

ActiveRecord matchers

accept_nested_attributes_for tests usage of the accepts_nested_attributes_for macro.
belong_to tests your belongs_to associations.
define_enum_for tests usage of the enum macro.
have_and_belong_to_many tests your has_and_belongs_to_many associations.
have_db_column tests that the table that backs your model has a specific column.
have_db_index tests that the table that backs your model has an index on a specific column.
have_many tests your has_many associations.
have_one tests your has_one associations.
have_readonly_attribute tests usage of the attr_readonly macro.
serialize tests usage of the serialize macro.
validate_uniqueness_of tests usage of validates_uniqueness_of.

ActionController matchers

filter_param tests parameter filtering configuration.
permit tests that an action places a restriction on the params hash.
redirect_to tests that an action redirects to a certain location.
render_template tests that an action renders a template.
render_with_layout tests that an action is rendered with a certain layout.
rescue_from tests usage of the rescue_from macro.
respond_with tests that an action responds with a certain status code.
route tests your routes.
set_session makes assertions on the session hash.
set_flash makes assertions on the flash hash.
use_after_action tests that an after_action callback is defined in your controller. (Aliased as #use_after_filter.)
use_around_action tests that an around_action callback is defined in your controller. (Aliased as #use_around_filter.)
use_before_action tests that a before_action callback is defined in your controller. (Aliased as #use_before_filter.)

Independent matchers

delegate_method tests that an object forwards messages to other, internal objects by way of delegation.

Getting started

RSpec

Include shoulda-matchers in your Gemfile:

For Rails 4.x:

group :test do
  gem 'shoulda-matchers', '~> 3.1'
end

For Rails 5.0:

group :test do
  gem 'shoulda-matchers', git: 'https://github.com/thoughtbot/shoulda-matchers.git', branch: 'rails-5'
end

Now you need to tell the gem a couple of things:

Which test framework you're using
Which portion of the matchers you want to use

You can supply this information by using a configuration block. Place the following in rails_helper.rb:

Shoulda::Matchers.configure do |config|
  config.integrate do |with|
    # Choose a test framework:
    with.test_framework :rspec
    with.test_framework :minitest
    with.test_framework :minitest_4
    with.test_framework :test_unit

    # Choose one or more libraries:
    with.library :active_record
    with.library :active_model
    with.library :action_controller
    # Or, choose the following (which implies all of the above):
    with.library :rails
  end
end

Now you can use matchers in your tests. For instance a model test might look like this:

RSpec.describe Person, type: :model do
  it { should validate_presence_of(:name) }
end

Availability of matchers in various example groups

Since shoulda-matchers provides four categories of matchers, there are four different levels where you can use these matchers:

ActiveRecord and ActiveModel matchers are available only in model example groups, i.e., those tagged with type: :model or in files located under spec/models.
ActionController matchers are available only in controller example groups, i.e., those tagged with type: :controller or in files located under spec/controllers.
The route matcher is available also in routing example groups, i.e., those tagged with type: :routing or in files located under spec/routing.
Independent matchers are available in all example groups.

If you are using ActiveModel or ActiveRecord outside of Rails and you want to use model matchers in certain example groups, you'll need to manually include them. Here's a good way of doing that:

RSpec.configure do |config|
  config.include(Shoulda::Matchers::ActiveModel, type: :model)
  config.include(Shoulda::Matchers::ActiveRecord, type: :model)
end

Then you can say:

describe MySpecialModel, type: :model do
  # ...
end

`should` vs `is_expected.to`

Note that in this README and throughout the documentation we're using the should form of RSpec's one-liner syntax over is_expected.to. The should form works regardless of how you've configured RSpec -- meaning you can still use it even when using the expect syntax. But if you prefer to use is_expected.to, you can do that too:

RSpec.describe Person, type: :model do
  it { is_expected.to validate_presence_of(:name) }
end

Minitest

Shoulda Matchers was originally a component of Shoulda, a gem that also provides should and context syntax via shoulda-context.

At the moment, shoulda has not been updated to support shoulda-matchers 3.x, so you'll want to add the following to your Gemfile:

group :test do
  gem 'shoulda', '~> 3.5'
  gem 'shoulda-matchers', '~> 2.0'
end

Now you can use matchers in your tests. For instance a model test might look like this:

class PersonTest < ActiveSupport::TestCase
  should validate_presence_of(:name)
end

Running tests

Unit tests

Unit tests are the most common kind of tests in this gem, and the best way to run them is by using Zeus.

You'll want to run zeus start in one shell, then in another shell, instead of using rspec to run tests, you can use zeus rspec. So for instance, you might say:

zeus rspec spec/unit/shoulda/matchers/active_model/validate_inclusion_of_matcher_spec.rb

As a shortcut, you can also drop the initial part of the path and say this instead:

zeus rspec active_model/validate_inclusion_of_matcher_spec.rb

Acceptance tests

The gem uses Appraisal to test against multiple versions of Rails and Ruby. This means that if you're trying to run a single test file, you'll need to specify which appraisal to use. For instance, you can't simply say:

rspec spec/acceptance/active_model_integration_spec.rb

Instead, you need to say

bundle exec appraisal 4.2 rspec spec/acceptance/active_model_integration_spec.rb

All tests

You can run all tests by saying:

bundle exec rake

Generating documentation

YARD is used to generate documentation, which can be viewed online. You can preview changes you make to the documentation locally by running

yard doc

from this directory. Then, open doc/index.html in your browser.

If you want to be able to regenerate the docs as you work without having to run yard doc over and over again, keep this command running in a separate terminal session:

rake docs:autogenerate

Contributing

Shoulda Matchers is open source, and we are grateful for everyone who's contributed so far.

If you'd like to contribute, please take a look at the instructions for installing dependencies and crafting a good pull request.

Compatibility

Shoulda Matchers is tested and supported against Rails 4.x, RSpec 3.x, Minitest 5, Minitest 4, and Ruby 2.x.

Versioning

Shoulda Matchers follows Semantic Versioning 2.0 as defined at http://semver.org.

License

About thoughtbot

Shoulda Matchers is maintained and funded by thoughtbot, inc. The names and logos for thoughtbot are trademarks of thoughtbot, inc.

We are passionate about open source software. See our other projects. We are available for hire.