I end-up here looking for some info about expect.assertions.

If useful, I think I'm using a different strategy to test error cases that don't need expect.assertions at all:

it("should login", async () => {
  // arrange
  const login = "login";
  const password = "password";
  // act & assert
  await expect(login(email, password))
    .rejects
    .toThrow("failed to login");
});

Cheers!