     |> Map.put(:valid, true)
   end
 
+  defp add_to_application_env(key, value) do
+    Application.put_env(:appsignal, :config,
+      Application.get_env(:appsignal, :config) ++ [{key, value}]
+    )
+  end
+
   defp init_config do
     Config.initialize()
     Application.get_all_env(:appsignal)[:config]

    assert default_configuration == init_config
  end

  test "valid configuration" do
    Application.put_env(
      :appsignal, :config,
      push_api_key: "00000000-0000-0000-0000-000000000000"
    )
    assert valid_configuration == init_config
  end

  test "app revision" do

      push_api_key: "-test",
      revision: "b5f2b9")
    assert "b5f2b9" = init_config()[:revision]
  end

  defp default_configuration do
