using assertions in waitFor blocks

[joprice]

I'm trying to figure out how to write something similar to the below waitFor call, where the passed closure has an assertion, which is expected to fail inline. As far as I can tell, the affirm functionality is internal. Could it be exposed to execute these callbacks outside the context of a test body, or is there another approach to accomplish this?

await waitFor(() => {
    expect(queryByText("Loading ...")).not.toBeInTheDocument();
  });