wojtekmach / phoenix_ecto

Phoenix and Ecto integration with support for concurrent acceptance testing

Phoenix/Ecto

A project that integrates Phoenix with Ecto, implementing all relevant protocols.

Usage

You can use :phoenix_ecto in your projects in two steps:

1. Add it to your mix.exs dependencies:

   def deps do
     [{:phoenix_ecto, "~> 4.0"}]
   end

2. List it as your application dependency:

   def application do
     [applications: [:logger, :phoenix_ecto]]
   end

Concurrent browser tests

This library also provides a plug called Phoenix.Ecto.SQL.Sandbox that allows developers to run acceptance tests powered by headless browsers such as ChromeDriver and Selenium concurrently. If you are not familiar with Ecto's SQL sandbox, we recommend you to first get acquainted with it by reading Ecto.Adapters.SQL.Sandbox documentation.

To enable concurrent acceptance tests, make sure you are using PostgreSQL and follow the instructions below:

1. Set a flag to enable the sandbox in config/test.exs:

   config :your_app, sql_sandbox: true

2. And use the flag to conditionally add the plug to lib/your_app/endpoint.ex:

   if Application.get_env(:your_app, :sql_sandbox) do
     plug Phoenix.Ecto.SQL.Sandbox
   end

   Make sure that this is placed before the line plug YourApp.Router (or any other plug that may access the database).

You can now checkout a sandboxed connection and pass the connection information to an acceptance testing tool like Hound or Wallaby.

Hound

To write concurrent acceptance tests with Hound, first add it as a dependency to your mix.exs:

{:hound, "~> 1.0"}

Make sure to start it at the top of your test/test_helper.exs:

{:ok, _} = Application.ensure_all_started(:hound)

Then add the following to your test case (or case template):

use Hound.Helpers

setup do
  :ok = Ecto.Adapters.SQL.Sandbox.checkout(YourApp.Repo)
  metadata = Phoenix.Ecto.SQL.Sandbox.metadata_for(YourApp.Repo, self())
  Hound.start_session(metadata: metadata)
  :ok
end

Hound supports multiple drivers like Chrome, Firefox, etc but it does not support concurrent tests under PhantomJS (the default).

Wallaby

To write concurrent acceptance tests with Wallaby, first add it as a dependency to your mix.exs:

{:wallaby, "~> 0.25", only: :test}

Wallaby can take care of setting up the Ecto Sandbox for you if you use use Wallaby.Feature in your test module.

defmodule MyAppWeb.PageFeature do
  use ExUnit.Case, async: true
  use Wallaby.Feature

  feature "shows some text", %{session: session} do
    session
    |> visit("/home")
    |> assert_text("Hello world!")
  end
end

If you don't use Wallaby.Feature, you can add the following to your test case (or case template):

use Wallaby.DSL

setup do
  :ok = Ecto.Adapters.SQL.Sandbox.checkout(YourApp.Repo)
  metadata = Phoenix.Ecto.SQL.Sandbox.metadata_for(YourApp.Repo, self())
  {:ok, session} = Wallaby.start_session(metadata: metadata)
end

Wallaby currently supports ChromeDriver and Selenium, allowing testing in almost any browser.

The Phoenix <-> Ecto integration

Thanks to Elixir protocols, the integration between Phoenix and Ecto is simply a matter of implementing a handful of protocols. We provide the following implementations:

• Phoenix.HTML.FormData protocol for Ecto.Changeset
• Phoenix.HTML.Safe protocol for Decimal
• Plug.Exception protocol for the relevant Ecto exceptions

Configuration

The Plug.Exception implementations for Ecto exceptions may be disabled by including the error in the mix configuration.

config :phoenix_ecto,
  exclude_ecto_exceptions_from_plug: [Ecto.NoResultsError]

Copyright and License

Copyright (c) 2015, Chris McCord.

Phoenix/Ecto source code is licensed under the MIT License.