Add tests for archive controller

test/music_library_web/controllers/archive_controller_test.exs

@@ -0,0 +1,17 @@
+defmodule MusicLibraryWeb.ArchiveControllerTest do
+  use MusicLibraryWeb.ConnCase
+
+  describe "GET /backup" do
+    test "returns a sqlite database file", %{conn: conn} do
+      conn = get(conn, "/backup")
+
+      assert response(conn, 200)
+      assert get_resp_header(conn, "content-type") |> hd() =~ "application/x-sqlite3"
+
+      [content_disposition] = get_resp_header(conn, "content-disposition")
+      assert content_disposition =~ "attachment"
+      assert content_disposition =~ "music_library_"
+      assert content_disposition =~ ".db"
+    end
+  end
+end