test.js

const tests = new Set();
const t = {
	total: 0,
	passed: 0,
	failed: 0,

	comment(message) {
		console.log(`# ${message}`);
	},

	ok(value, message = 'should be ok', ...rest) {
		const output = `ok ${++t.total} ${message}`;

		if (value) {
			++t.passed;
			console.log(output);
		} else {
			++t.failed;
			console.log(`not ${output}`);
			console.assert(value, ...rest);
		}
	},

	equal(actual, expected, message = 'should be equal') {
		t.ok(actual === expected, message, { actual, expected });
	},

	deepEqual(actual, expected, message = 'should be deeply equal') {
		const aa = JSON.stringify(actual);
		const bb = JSON.stringify(expected);

		t.ok(aa === bb, message, { actual, expected });
	},
};

export function test(description, fn) {
	tests.add([fn && description, fn || description]);
}

export function title(value) {
	test(`\n#  ${value}\n# `, () => null);
}

setTimeout(async () => {
	console.log('TAP version 13');

	for (const [description, fn] of tests) {
		if (description) {
			t.comment(description);
		}

		await fn(t);
	}

	t.comment(`pass: ${t.passed}`);
	t.comment(`fail: ${t.failed}`);

	console.log(`1..${t.total}`);
});