Forgery is a slim though extensible test data generator in Elixir.

Forgery provides a few simple APIs to work with. To get started, you need to implement the make/2 callback:

defmodule MyUser do
  defstruct [:id, :username, :password]
end

defmodule MyFactory do
  use Forgery

  def make(:user, fields) do
    fields
    |> put_new_field(:id, make_unique_integer())
    |> put_new_field(:username, "user" <> to_string(make_unique_integer()))
    |> create_struct(MyUser)
  end
end

iex> import MyFactory
iex>
iex> %MyUser{} = make(:user)
iex> %MyUser{id: 42} = make(:user, id: 42)
iex> [%MyUser{}, %MyUser{}] = make_many(:user, 2)

And just as simple as that!

Ecto integration

Forgery was built with easy Ecto integration in mind, though not limiting to it.

For example if you use Ecto and have MyRepo. You can add a function, says insert!, into the factory:

defmodule MyFactory do
  def insert!(factory, fields \ %{}) do
    :user
    |> make(fields)
    |> MyRepo.insert!()
  end

  def insert_many!(factory, amount, fields \ %{}) when amount >= 1 do
    [%schema{} | _] = entities = make_many(:user, amount, fields)

    {_, persisted_entities} = MyRepo.insert_all(schema, entities, returning: true)

    persisted_entities
  end
end

user = insert!(:user)
users = insert_many!(:user, 10, %{password: "1234567890"})