backend-template/packages/cli/test/index.test.ts

import {describe, it, expect, vi, beforeAll, afterAll} from 'vitest';

import { createCli } from '../src/cli';
import { addCommands } from '../src/commands';
import yargs from 'yargs';
import { AdderServiceImpl, InvalidArgumentTypeError, ArgumentOutOfRangeError } from '../src/modules/adder';

vi.mock('process');

describe('blah', () => {
	let cli: yargs.Argv;
	let exit: vi.Mock<typeof process.exit>;
	let exitReal: typeof process.exit;

	beforeAll(() => {
		exitReal = process.exit.bind(process);
		const processMut = process as unknown as Record<string, unknown>;
		processMut.exit = exit = vi.fn();
	});

	afterAll(() => {
		process.exit = exitReal = process.exit.bind(process);
	});

	it('returns result when successful', async () => {
		cli = createCli(['add', '1', '2']);
		addCommands(cli);
		await cli.parse();
		expect(exit).toHaveBeenCalledWith(0);
  });

	it('returns error when given invalid inputs', async () => {
		vi.spyOn(AdderServiceImpl.prototype, 'addNumbers').mockImplementationOnce(() => {
			throw new InvalidArgumentTypeError('Invalid input');
		});

		cli = createCli(['add', '1', '2']);
		addCommands(cli);
		await cli.parse();
		expect(exit).toHaveBeenCalledWith(-1);
	});

	it('returns error when given out-of-range inputs', async () => {
		vi.spyOn(AdderServiceImpl.prototype, 'addNumbers').mockImplementationOnce(() => {
			throw new ArgumentOutOfRangeError('Out of range');
		});

		cli = createCli(['add', '1', '2']);
		addCommands(cli);
		await cli.parse();
		expect(exit).toHaveBeenCalledWith(-2);
	});

	it('returns error when an unexpected error occurs', async () => {
		vi.spyOn(AdderServiceImpl.prototype, 'addNumbers').mockImplementationOnce(() => {
			throw new Error('Unexpected error');
		});

		cli = createCli(['add', '1', '2']);
		addCommands(cli);
		await cli.parse();
		expect(exit).toHaveBeenCalledWith(-2);
	});
});