CleanMock replaces fixtures in tests. You define mock blueprints for your models, then call mock.build, mock.create, or mock.fetch to produce test objects on the fly.
Adding and removing fields is easy because mocks use your existing classes (ActiveRecord, Sequel, plain Ruby, etc.) directly.
Similar to FactoryBot but without any method_missing magic. A pointer to the newly created object is passed to your block and you are free to do with it as you please. This means no unexpected behavior and nothing to work around.
gem install clean-mock
or in Gemfile
gem 'clean-mock'then require it
require 'clean-mock'CleanMock requires String#classify, String#constantize, and String#singularize to be defined.
These are available via ActiveSupport or as a lightweight alternative:
require 'dry/inflector'
class String
def classify; Dry::Inflector.new.classify self; end
def constantize; Dry::Inflector.new.constantize self; end
def singularize; Dry::Inflector.new.singularize self; end
endThere are three equivalent ways to define mocks:
# block style - define multiple mocks at once
mock do
define :user do |user, opts|
# ...
end
define :org do |org, opts|
# ...
end
end
# explicit style
mock.define :user do |user, opts|
# ...
end
# shorthand style
mock :user do |user, opts|
# ...
endThe second argument to define controls which class is instantiated:
# default - class is resolved from name: :user -> User
mock.define(:user) do |user, opts|
# user is User.new
end
# explicit class
mock.define(:admin_user, class: User) do |user, opts|
# user is User.new
end
# dynamic class from symbol - creates the class if it doesn't exist
mock.define(:thing, class: :thing) do |thing, opts|
# thing is Thing.new (class created via Object.const_set if needed)
end
# no class - return anything you want
mock.define(:random_name, class: false) do |opts|
['John', 'Josh', 'Mike'].sample
endWhen class: false, only opts is passed to the block (no model argument), and whatever the block returns becomes the mock value.
These helpers are available inside the define block:
Create named variants of an object. Traits are activated by passing their names to build/create/fetch.
mock.define :user do |user, opts|
user.is_admin = false
trait :admin do
user.is_admin = true
end
end
mock.build(:user).is_admin # false
mock.build(:user, :admin).is_admin # trueMultiple traits can be combined:
mock.build(:user, :admin, :with_org)Passing an undefined trait raises an error:
mock.build(:user, :nonexistent) # RuntimeError: Trait [nonexistent] not foundDefine or overload a singleton method on the model instance.
mock.define :user do |user, opts|
func :full_greeting do
"Hello, I am #{name}"
end
end
mock.build(:user).full_greeting # "Hello, I am ..."Auto-incrementing integer sequence. Each name tracks its own counter independently.
mock.define :user do |user, opts|
user.name = 'User %s' % sequence(:user) # User 1, User 2, User 3...
user.email = 'user-%s@test.com' % sequence # uses default :seq name
endWith a custom start value:
mock.define :item do |item, opts|
item.position = sequence(:pos, 100) # 101, 102, 103...
endCreate and link another mock object. Calls CleanMock.create on the related mock and assigns its id to the current model.
mock.define :user do |user, opts|
trait :with_org do
create :org # equivalent to: user.org_id = mock.create(:org).id
end
endThe field name defaults to name.singularize + '_id'. Pass an explicit field to override:
create :org, 'organization_id' # user.organization_id = mock.create(:org).idRegister a callback that runs after create_mock saves the model. Only fires when using mock.create or mock.fetch, not mock.build.
mock.define :user do |user, opts|
after_create do
# runs after save
# user has been persisted at this point
end
endafter_create is an alias for after_save.
Instantiate the mock object without saving.
user = mock.build(:user)
user = mock.build(:user, :admin, email: 'foo@bar.com')Instantiate and call .save on the model (if it responds to save), then run any after_save callbacks.
user = mock.create(:user, :admin)
user.id # set by your ORM after saveLike create, but memoized - returns the same object when called with identical arguments.
org = mock.fetch(:org)
org2 = mock.fetch(:org)
org.equal?(org2) # true - same object
# different args produce different objects
a = mock.fetch(:user, email: 'a@a.com')
b = mock.fetch(:user, email: 'b@b.com')
a.equal?(b) # falseBuild the object and return its .attributes hash, filtered to present values. Useful with ActiveRecord models.
attrs = mock.attributes_for(:user, :admin)
# { name: 'User 1', email: 'john@example.com', is_admin: true }mock :user do |user, opts|
user.name = 'User %s' % sequence(:user)
user.address = 'Somewhere %s' % sequence
user.email = opts[:email] || Faker::Internet.email
user.is_admin = false
func :say_ok do
'ok'
end
trait :admin do
user.is_admin = true
end
trait :with_org do
create :org
end
after_create do
# runs after save, user is persisted
end
end
mock.define(:org) {}
mock.define :foo, class: false do
Class.new do
def foo
:bar
end
end.new
end
# build - no save
user = mock.build(:user)
user.class # User
user.name # 'User 1'
user.is_admin # false
# create - with save
user = mock.create(:user, :admin, email: 'foo@bar.baz')
user.name # 'User 2'
user.email # 'foo@bar.baz'
user.is_admin # true
# create with linked object
user = mock.create(:user, :with_org)
user.org_id # 11 (or whatever org.id returns)
# fetch - memoized create
org1 = mock.fetch(:org)
org2 = mock.fetch(:org)
org1.equal?(org2) # true
# class: false
mock.build(:foo).foo # :barAfter checking out the repo, run bundle install to install dependencies. Then, run rspec to run the tests.
Bug reports and pull requests are welcome on GitHub at https://github.com/dux/clean-mock.
The gem is available as open source under the terms of the MIT License.