Makery

Welcome to Makery. A lightweight and fast factory library.

Why Makery over FactoryBot?

Instantialize your object relationship graph without hitting the database

You can use Makery's delayed execution blocks to create arbitrarily complex relationships without costly database transactions. This allows you to run tests and order of magnitude faster than equivalent tests using FactoryBot.

Small

Makery is 62 lines of code, a 96% reduction over FactoryBot.

Speed

When just initializing objects, Makery is a 12x-37x speed improvement over FactoryBot. Makery also allows you to easily set up relationships between objects without using the database, which is another order of magnitude speed boost if you are testing business logic. Run bundle exec ruby benchmark.rb and look at benchmark.rb for more details.

ORM independence

Makery is completely ORM independent. You can use it easily with any data object class and no special flags needed.

Why FactoryBot over Makery

• You like multiple factory definitions instead of traits
• You need the before or after callbacks for things besides setting up associations

Installation

echo "gem 'makery'" >> Gemfile
bundle

Usage

Defining a factory

Makery leverages named arguments everywhere to avoid use of DSLs. Create or fetch a factory using Makery[YourClass]. Then set the base attributes with #base(attr_hash)

class Post
  attr_accessor :foo, :bar
end

maker = Makery[Post]
maker.base(
  foo: 1,
  bar: 2
)

klass = Struct.new(:foo, :bar)

maker = Makery[klass]
maker.base(
  foo: 1
  bar: 2
)

class User < ActiveRecord::Base
end

Makery[User].base(
  email: "[email protected]",
)

Using the factory

Use #call to create a new object of your class.

post = Makery[Post].call
post.foo #=> 1

object = Makery[klass].call
object.foo #=> 1

Makery[User].call.email == "[email protected]" #=> true

Makery uses anything that responds to call for delayed execution, usually a Proc. There is a single argument passed for accessing the other attributes. You can also pass overrides into the call to maker.

Makery[klass].call(foo: ->(m) { m[:bar] + 1 }).foo == 3 #=> true

Makery uses traits to allow further specification of a class. Traits are merged over the base attributes.

maker = Makery[klass]
maker.base(
  foo: 1
  bar: 2
)

maker.trait(
  :big_foo,
  foo: 10
)

Makery[klass].call(:big_foo).foo == 10 #=> true

Sequences

maker = Makery[User]
maker.base(
  email: ->(m) { "user-#{m.i}@biz.com" }
)

Makery[User].call.email #=> "[email protected]"
Makery[User].call.email #=> "[email protected]"

Associations

The object passed to call in delayed execuption provides an object method for creating associations between objects. Use it where you would pass the instance.

For example if you have a one to many association that could be described like so:

boss = User.new
employee = User.new
boss.employees = [employee]

Makery could replicate it like this:

maker = Makery[User]
maker.base(
  boss: ->(m) { Makery[User].call(employees: [m.object]) }
)

employee = maker.call
boss = employee.boss

What kinds of classes can use this?

Any class used needs writer methods corresponding to each attribute and that should be it.

How does this work behind the scenes?

It is all about hashes and merging. The base attribute set is always there at the bottom and each trait merges over the base. Finally the named arguments are merged over all of that. Once that is merged, any attribute values that respond to call are called. Finally, an instance of the class being factoried has its attributes set from the attribute hash.

ActiveRecord and Sequel

Makery operates independently of ActiveRecord or any ORM. You could do one of the following.

maker = Makery[User]
maker.base(
  email: "[email protected]"
  password: "a password"
)

user = Makery[User].call
user.save

# or a method to handle it like FactoryBot

def create(klass, *args)
  Makery[klass].call(*args).tap(&:save)
end
create(User)

Custom Factories

A way to make custom factories has been provided via the #[]= method. Anything can be stored, but you probably want to use a proc. The following example uses a proc with default arguments to create a JSON document.

Makery["user registration request body"] = ->(username: 'joe', password: '1234') {
  {user: {username: username, password: password} }.to_json
}

Makery["user registration request body"].call

Development

After checking out the repo, run bin/setup to install dependencies. Then, run bundle exec rake spec to run the tests.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/kwstannard/makery. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.

License

The gem is available as open source under the terms of the MIT License.

Code of Conduct

Everyone interacting in the Makery project’s codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.