blacksmith

Data generation framework for Elixir.

In testing, sometimes it's useful to create records in the form of maps. Blacksmith makes it easy.

First, install Blacksmith:

Right now, you'll use mix with a git dependency. In your mix.exs file, add the blacksmith dependency:

def deps do
  [{:blacksmith, git: "git://github.com/batate/blacksmith.git"}]
end

To use Faker to generate fake data you will also have to add :faker or :blacksmith to your application list:

def application do
  [applications: applications(Mix.env)]
end

defp applications(:test), do: applications(:all) ++ [:blacksmith]
defp applications(_all),  do: [:logger]

Next, tell Blacksmith how to save one record, or many records:

defmodule do Blacksmith.Config
  def save(repo, model) do
    repo |> save( model )
  end
  
  def save_all(repo, list_of_models) do
    repo |> save_all( list_of_models )
  end
end

Next, perhaps in test_helper for convenience or somewhere in lib for speed, register each of your new models with Forge. Use Faker for fake values:

defmodule Forge do
  use Blacksmith
  
  
  register :user, 
    name: Faker.Name.first_name,          
    type: :map, 
    email: Faker.Internet.email, 
    description: Faker.Lorem.sentence, 
    roles: [], 
    always_the_same: "string"
    
  # this will create a user with roles set to [:admin]
  register :admin, 
    type: :blacksmith, 
    prototype: user,
    roles: ["admin"]
end

Now you can create a user, generating all of the default values:

  user = Forge.user

or a saved user, with the name attribute overridden, and a new attribute of favorite_language:

  user = Forge.saved_user Models.User, name: "Will Override", favorite_language: "Elixir"

or a list of 5 users

  user = Forge.user_list 5

or a saved list of 5 admins

  admin = Forge.saved_admin_list repo, 5

Create a list using a few common data elements:

  Forge.having survey_id: some_survey.id, author: Forge.user do
    question = Forge.question   # will share the same survey id and user from above
  end

Next release: allow nesting of having blacks.