import assert from 'node:assert/strict';
import test from 'node:test';
import { formatDeadline } from './deadlineFormat.js';

test('ISO closes_at is formatted as "до DD.MM HH:mm" in local time', () => {
	const closesAt = new Date(2026, 9, 31, 18, 0, 0); // 31 октября, 18:00, локальное время
	assert.equal(formatDeadline(closesAt.toISOString()), 'до 31.10 18:00');
});

test('single-digit day/month/hour/minute are zero-padded', () => {
	const closesAt = new Date(2026, 0, 5, 9, 3, 0); // 5 января, 09:03
	assert.equal(formatDeadline(closesAt.toISOString()), 'до 05.01 09:03');
});

test('a Date instance is accepted directly, not only an ISO string', () => {
	const closesAt = new Date(2026, 11, 1, 0, 0, 0);
	assert.equal(formatDeadline(closesAt), 'до 01.12 00:00');
});

test('falsy or invalid input returns null instead of throwing', () => {
	assert.equal(formatDeadline(null), null);
	assert.equal(formatDeadline(undefined), null);
	assert.equal(formatDeadline(''), null);
	assert.equal(formatDeadline('not-a-date'), null);
});