brood

gem install "brood"

class Department
  attr_accessor :id, :name, :users
end

class User
  attr_accessor :id, :name, :department, :counter
end

# Define fabricators for models at spec/fabricators/*_fabricator.rb.
Fabricator(:department) do
  id { sequence(:id) }
  name
end
Fabricator(:user) do
  id { sequence(:id) }
  name { Faker::Name.name }
  department
end

# Instantiate a brood:
@brood = Brood.new

# Fabricate objects:
gizmos = @brood.create([:department, :gizmos], {name: "Gizmos"}) # => Department instance
@brood.create([:user, :bar], {id: 12, name: "Bar"}) # => User instance
@brood.create([:user, :baaz], {name: "Baaz"}) # => User instance

# Pass a block to customize the object (forwarded to the Fabricator block argument):
@brood.create([:user, :baar], {name: "Baar"}) do |user|
  user.department = gizmos
end

# Skip persistence (calls Fabricate.build)
gadgets = @brood.build([:department, :gadgets], {name: "Gadgets"}) # => Department instance
foobar = @brood.build([:user, :foobar], {name: "Foobar"}) do |user|
  user.department = gadgets
end # => User instance

# Retrieve objects:
@brood.get([:user, :bar]) # => User instance
@brood.get([:user, :baaz]) # => User instance
@brood.get([:user, :foobar]) # => User instance
@brood.get([:bogus, :bar]) # raises Brood::UnknownObjectTypeError
@brood.get([:user, :quux]) # raises Brood::ObjectNotFoundError

# Pass a block to customize and lock the object:
@brood.get([:user, :bar]) do |user|
  counter = user.counter
  sleep 0.0001
  user.counter = counter + 1
end # => User instance