async function assertInvalidConfig(values, message) {
	const configs = createFlatConfigArray(values);

	assert.throws(() => {
		configs.normalizeSync();
		configs.getConfig("foo.js");
	}, message);
}
Asserts that a given set of configs results in an invalid config.
@param {*[]} values An array of configs to use in the config array.
@param {string|RegExp} message The expected error message.
@returns {void}
@throws {AssertionError} If the config is valid or if the error
     has an unexpected message.