Introduce support for 3rd-party auth (OAuth2 & LDAP)

Signed-off-by: Thomas Citharel <tcit@tcit.fr>

test/service/auth/authentificator_test.exs

@@ -0,0 +1,34 @@
+defmodule Mobilizon.Service.Auth.AuthenticatorTest do
+  use Mobilizon.DataCase
+
+  alias Mobilizon.Service.Auth.Authenticator
+  alias Mobilizon.Users
+  alias Mobilizon.Users.User
+  import Mobilizon.Factory
+
+  @email "email@domain.tld"
+  @password "password"
+
+  describe "test authentification" do
+    test "authenticate/1 checks the user's password" do
+      {:ok, %User{} = user} = Users.register(%{email: @email, password: @password})
+      Users.update_user(user, %{confirmed_at: DateTime.utc_now()})
+
+      assert {:ok, _} = Authenticator.authenticate(@email, @password)
+
+      assert {:error, :bad_password} ==
+               Authenticator.authenticate(@email, "completely wrong password")
+    end
+  end
+
+  describe "fetch_user/1" do
+    test "returns user by email" do
+      user = insert(:user)
+      assert Authenticator.fetch_user(user.email).id == user.id
+    end
+
+    test "returns nil" do
+      assert Authenticator.fetch_user("email") == {:error, :user_not_found}
+    end
+  end
+end