Test mode

[Papipo]

Hi!

I've been lost for two days trying to find a proper way of doing testing like you would do with Omniauth.
As a workaround I've set up Bypass, but I find the process clumsy and verbose, since I need to configure each Strategy host to map to different Bypass ports, etc.

So I am willing to tackle the feature but I would like some pointers about how to implement it so we can get a mergeable pull requests.

Thanks.

[doomspork]

Howdy @Papipo! This is definitely something everyone on the @ueberauth/developers team has wanted though I fear we've never come to consensus on the best way to do so.

If you're interested in pursuing this feature we can use this issue to discuss the different approaches and hopefully decide on one to take.

[Papipo]

#69 is great. I copy a couple of feature requests I put there:

• Adding mocks at runtime.
• Forcing an authentication failure.

[yordis]

We should allow swapping the implementation based on the environment. We shouldn't mock or come out with an implementation that leaks abstraction.

In my opinion, the issue is that Ueberauth needs to embrace an adapter pattern.

[axelson]

Can we re-open this since it isn't actually fixed? (as far as I can tell)

[yordis]

@axelson done

[elvanja]

If it helps anyone, I used this idea to test various paths. It is not generally applicable to every situation, but it is easily adaptable (pun intended 😄):

# in test/support/test_ueberauth_strategy.ex
defmodule Experiment.TestUeberauthStrategy do
  alias Ueberauth.Auth
  alias Ueberauth.Failure

  use Ueberauth.Strategy,
    uid_field: :id,
    ignores_csrf_attack: true

  def handle_request!(conn), do: aliased_strategy(conn).handle_request!(conn)

  def handle_callback!(%{assigns: %{ueberauth_auth: %Auth{}}} = conn), do: conn
  def handle_callback!(%{assigns: %{ueberauth_failure: %Failure{}}} = conn), do: conn
  def handle_callback!(conn), do: aliased_strategy(conn).handle_callback!(conn)

  defp aliased_strategy(%{private: %{ueberauth_request_options: %{options: opts}}} = conn) do
    Keyword.fetch!(opts, :aliased_strategy)
  end
end

# in config/test.exs
config :ueberauth, Ueberauth,
  providers: [microsoft: {Experiment.TestUeberauthStrategy, [aliased_strategy: Ueberauth.Strategy.Microsoft]}]

# in some test, e.g. test/experiment_web/controllers/auth_controller_test.exs
defmodule ExperimentWeb.AuthControllerTest do
  alias Ueberauth.Auth

  test "uses mock", %{conn: conn} do
    # request login
    conn = get(conn, ~p"/auth/microsoft")
    assert redirected_to(conn, 302) =~ "https://login.microsoftonline.com"

    # callback from provider with successfully logged in user
    conn =
      conn
      |> recycle()
      |> assign(:ueberauth_auth, %Auth{provider: :microsoft, info: %{email: "some.email@domain.com"}})

    conn =
      get(conn, ~p"/auth/microsoft/callback", %{
        code: UUID.generate(),
        session_state: UUID.generate(),
        state: UUID.generate()
      })

    # whatever further assertions you might need
  end
end