Project: shoulda-callback-matchers

#Shoulda Callback Matchers

Matchers to test before, after and around hooks(currently supports method and object callbacks):

Usage

Method Callbacks:

describe Post do
  it { is_expected.to callback(:count_comments).before(:save) }
  it { is_expected.to callback(:post_to_twitter).after(:create) }
  it { is_expected.to callback(:evaluate_if_is_should_validate).before(:validation) }
  it { is_expected.to callback(:add_some_convenience_accessors).after(:find) }

  # with conditions

  it { is_expected.to callback(:assign_something).before(:create).if(:this_is_true) }
  it { is_expected.to callback(:destroy_something_else).before(:destroy).unless(:this_is_true) }
end

describe User do
  it { is_expected.not_to callback(:make_email_validation_ready!).before(:validation).on(:update) }
  it { is_expected.to callback(:make_email_validation_ready!).before(:validation).on(:create) }
  it { is_expected.to callback(:update_user_count).before(:destroy) }
end

Object Callbacks:

class CallbackClass
  def before_save
	...
  end

  def after_create
	...
  end

  def before_validation
	...
  end

  def after_find
	...
  end
end

describe Post do
  it { is_expected.to callback(CallbackClass).before(:save) }
  it { is_expected.to callback(CallbackClass).after(:create) }
  it { is_expected.to callback(CallbackClass).before(:validation) }
  it { is_expected.to callback(CallbackClass).after(:find) }

	# with conditions
  it { is_expected.to callback(CallbackClass).before(:create).if(:this_is_true) }
  it { is_expected.to callback(CallbackClass).after(:find).unless(:is_this_true?) }
end

describe User do
  it { is_expected.not_to callback(CallbackClass).before(:validation).on(:update) }
  it { is_expected.to callback(CallbackClass).before(:validation).on(:create) }
  # Only Rails > 3.2+
  it { is_expected.to callback(CallbackClass).before(:validation).on([:create, :update]) }
  it { is_expected.to callback(CallbackClass).before(:destroy) }
end

This will test:

the method call
method existence

Either on the model itself or on the callback object. Be aware that obviously this does not test the callback method or object itself. It makes testing via triggering the callback events (validation, save) unnecessary, but you still have to test the called procedure seperately.

In Rails 3 or 4 and Bundler, add the following to your Gemfile:

group :test do
  gem 'shoulda-callback-matchers', '~> 1.1.1'
end

This gem uses semantic versioning, so you won't have incompability issues with patches.

rspec-rails needs to be in the development group so that Rails generators work.

group :development, :test do
  gem "rspec-rails"
end

Shoulda will automatically include matchers into the appropriate example groups.

Troubleshooting

RSpec + Spring

undefined method `callback'

If you're getting this error, it's probably due to classes being redefined by Spring - currently this library does not accommodate for reloaded classes. The easiest fix is to load the matchers into the test library config in your rails_helper.rb:

RSpec.configure do |config|
  config.include(Shoulda::Callback::Matchers::ActiveModel)
end

Credits

This gem is maintained by me and its contributors, Shoulda is maintained and funded by thoughtbot

Contributors & Contributions

@pvertenten (callback objects)
@johnnyshields (bugfixes)
@esbarango (README updates)
@yuku-t (Rails 4.2 Support)

Let's make this gem useful, send me a PR if you've discovered an issue you'd like to fix!

shoulda-callback-matchers

Development