TestDispatchForm

Helper to test the dispatch of Phoenix forms in Elixir applications. This will make it easier to write integration tests to check if forms in Phoenix templates will submit to the intended controller action with the right params.

Dependencies

• Floki v0.25.x and up
• TestSelector

Installation

If available in Hex, the package can be installed by adding test_dispatch_form to your list of dependencies in mix.exs:

def deps do
  [
    {:test_dispatch_form, "~> 0.1.0"}
  ]
end

Use

Import TestDispatchForm in your test module or your test case and you can call dispatch_form_with/3 from there.

To use dispatch_form_with/3 a request has to be made to a page where a form is present. The conn that is received will be parsed by the dispatch_form_with/3 and the form will be dispatched with the attributes that are given or the default values when they are not given.

defmodule MyAppWeb.MyTest do
  use MyAppWeb.ConnCase
  import TestDispatchForm

  test "dispatches form with attributes and entity" do
    conn = build_conn()

    assert conn
           |> get(Routes.user_path(conn, :new))
           |> dispatch_form_with(%{name: "John Doe", email: "john@doe.com"}, :user)
           |> redirected_to(Routes.user_path(conn, :index))
  end

  test "dispatches form with default values and test_selector" do
    conn = build_conn()

    assert conn
           |> get(Routes.user_path(conn, :index))
           |> dispatch_form_with(User.IndexView.test_selector("batch-action"))
           |> html_response(200)
  end
end

dispatch_form_with/3 will find a form in the HTML response of the given conn by entity or by test_selector, or, if no entity or test_selector is provided, it will target the last form found in the response.

Next it will look for form controls (inputs, selects), convert these to params and use the attributes passed to dispatch_form_with/3 to update the values of the params. The params will now only contain field keys found in the controls of the form.

If an entity is given, the params will be prepended by this entity. So for:

dispatch_form_with(conn, %{name: "John Doe", email: "john@doe.com"}, :user)

this will result in the following params:

%{"user" => %{name: "John Doe", email: "john@doe.com"}}

Ultimately, the conn is dispatched to the conn's private.phoenix_endpoint using Phoenix.ConnTest.dispatch/5, with the params and with the method and action found in the form.