import { promiseChain } from 'main';

describe('promiseChain', () => {
    test('Promises', async () => {
        const results: number[] = [];

        const thenAdd = (x: number, wait: number) => {
            return new Promise(resolve => setTimeout(resolve, wait)).then(() => {
                results.push(x);
                return x;
            });
        };
        const tasks = [() => thenAdd(1, 500), () => thenAdd(2, 50), () => thenAdd(3, 0)];
        await expect(promiseChain(tasks)).resolves.toEqual([1, 2, 3]);
        expect(results).toEqual([1, 2, 3]);
    });
});