test-mock-return-in-hook

a mock return value set in a beforeEach instead of the setup factory

Deterministic checkadvisory by defaultbasetests

The argument

This rule states its summary and proves it with an example.

The proof

failsubject.unit.test.ts

import { expect, describe, test, jest, beforeEach } from '@jest/globals';

const mockGetProfile = jest.fn<() => string>();

describe('subject', () => {
	beforeEach(() => {
		mockGetProfile.mockReturnValue('p.png');
	});

	test('reads the profile', () => {
		expect(mockGetProfile()).toBe('p.png');
	});
});

passsubject.unit.test.ts

import { expect, describe, test, jest } from '@jest/globals';

const mockGetVersion = jest.fn<() => string>();

const setupVersion = () => {
	mockGetVersion.mockReturnValue('1.0.0');

	return { version: '1.0.0' };
};

describe('subject', () => {
	test('reads the version', () => {
		const { version } = setupVersion();

		expect(mockGetVersion()).toBe(version);
	});
});

Turn it down

Both lines go in your lightsout.config.json.

"standards-checks": { "test-mock-return-in-hook": "advisory" }

"standards-checks": { "test-mock-return-in-hook": "off" }