def METHOD_NAME(
    fmt: str | None, tester: CommandTester, tmp_path: Path
) -> None:
    package = "package"
    path = tmp_path / package
    options = [path.as_posix()]
    if fmt:
        options.insert(0, f"--readme {fmt}")
    tester.execute(" ".join(options))
    poetry = verify_project_directory(path, package, package, None)
    assert poetry.local_config.get("readme") == f"README.{fmt or 'md'}"