import { backgroundTask } from '../src/index.js';

describe('A background task', () => {
	it('initially does nothing.', done => {
		const task = backgroundTask(() =>
			done(new Error('Background tasks should not spontaneously execute.'))
		);
		expect().nothing();
		setTimeout(done, 50);
	});

	it('runs a task (but not right away)', done => {
		let shouldRun = false;
		const task = backgroundTask(() => {
			expect(shouldRun).toBeTruthy();
			done();
		});

		task();
		shouldRun = true;
		setTimeout(done, 50);
	});

	it('passes params', done => {
		let testVal = Math.random();
		const task = backgroundTask(val => {
			expect(val).toEqual(testVal);
			done();
		});

		task(testVal);
		setTimeout(done, 50);
	});

	it('queues multiple calls to be run sequentially', done => {
		let testVal = ['a', 'd', 'q'];
		const task = backgroundTask((val, index) => {
			expect(val).toEqual(testVal[index]);
			if (index === testVal.length - 1) {
				done();
			}
		});

		testVal.map(task);
	});
});