ExMachina
ExMachina makes it easy to create test data and associations. It works great with Ecto, but is configurable to work with any persistence library.
Installation
In mix.exs
, add the ExMachina dependency:
def deps do
[{:ex_machina, "~> 0.0.1"}]
end
Add :ex_machina
to your application list:
def application do
[applications: app_list(Mix.env)]
end
defp app_list(:test), do: [:ex_machina | app_list]
defp app_list(_), do: app_list
defp app_list, do: [:logger]
Using with Ecto
# test/factories.ex
defmodule MyApp.Factories do
# MyApp.Repo is an Ecto Repo.
# It will automatically be used when calling `create`
use ExMachina, repo: MyApp.Repo
def factory(:config) do
# Factories can be plain maps
%{url: "http://example.com"}
end
def factory(:article) do
%Article{
title: "My Awesome Article"
}
end
def factory(:comment, attrs) do
%Comment{
body: "This is great!",
author_email: sequence(:email, &"email-#{&1}@example.com"),
article_id: assoc(attrs, :article).id
}
end
end
Then use it in your tests. This is an example with Phoenix.
defmodule MyApp.MyModuleTest do
use MyApp.ConnCase
# You can also import this in your MyApp.ConnCase if using Phoenix
import MyApp.Factories
test "shows comments for an article" do
conn = conn()
article = create(:article)
comment = create(:comment, article: article)
conn = get conn, article_path(conn, :show, article.id)
assert html_response(conn, 200) =~ article.title
assert html_response(conn, 200) =~ comment.body
end
end
Using without Ecto
You can use ExMachina without Ecto, by using just the build
function, or by
defining save_function/1
in your module.
defmodule MyApp.JsonFactories do
# Note `repo` was not passed as an option
use ExMachina
def factory(:user), do: %User{name: "John"}
def save_function(record) do
# Poison is a library for working with JSON
Poison.encode!(record)
end
end
# Will build and then return a JSON encoded version of the map
MyApp.JsonFactories.create(:user)
You can do something similar while also using Ecto by defining a new function.
This gives you the power to call create
and save to Ecto, or call build_json
or create_json
to return encoded JSON objects.
defmodule MyApp.Factories do
use ExMachina, repo: MyApp.Repo
def factory(:user), do: %User{name: "John"}
# builds the object and then encodes it as JSON
def build_json(factory_name, attrs) do
build(factory_name, attrs) |> Poison.encode!
end
# builds the object, saves it to Ecto and then encodes it
def create_json(factory_name, attrs) do
create(factory_name, attrs) |> Poison.encode!
end
end
License
ExMachina is Copyright © 2015 thoughtbot. It is free software, and may be redistributed under the terms specified in the LICENSE file.
About thoughtbot
ExMachina is maintained and funded by thoughtbot, inc. The names and logos for thoughtbot are trademarks of thoughtbot, inc.
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