Fold RequireLogin plug into Auth module

test/music_library_web/plug/auth_test.exs

@@ -0,0 +1,43 @@
+defmodule MusicLibraryWeb.AuthTest do
+  use ExUnit.Case, async: true
+  use Plug.Test
+
+  alias MusicLibraryWeb.Auth
+
+  defp setup_conn(_config) do
+    conn =
+      conn(:get, "/any-path")
+      |> Phoenix.ConnTest.init_test_session(%{})
+      |> Phoenix.ConnTest.fetch_flash()
+
+    %{conn: conn}
+  end
+
+  describe "require_logged_in/2" do
+    setup [:setup_conn]
+
+    test "when logged out, it redirects to /login", %{conn: conn} do
+      conn = Auth.require_logged_in(conn, [])
+
+      {"location", location} =
+        conn.resp_headers
+        |> List.keyfind("location", 0)
+
+      assert conn.status == 302
+      assert conn.state == :sent
+      assert conn.halted
+      assert location == "/login"
+      assert conn.assigns.flash == %{"error" => "You must be logged in to access this page"}
+    end
+
+    test "when logged in, it passes through", %{conn: conn} do
+      conn =
+        conn
+        |> Phoenix.ConnTest.init_test_session(%{logged_in: true})
+        |> Auth.require_logged_in([])
+
+      assert conn.status == nil
+      assert conn.state == :unset
+    end
+  end
+end