astro/examples/with-vitest/test/basic.test.ts

import { assert, expect, test } from 'vitest';

// Edit an assertion and save to see HMR in action

test('Math.sqrt()', () => {
	expect(Math.sqrt(4)).toBe(2);
	expect(Math.sqrt(144)).toBe(12);
	expect(Math.sqrt(2)).toBe(Math.SQRT2);
});

test('JSON', () => {
	const input = {
		foo: 'hello',
		bar: 'world',
	};

	const output = JSON.stringify(input);

	expect(output).eq('{"foo":"hello","bar":"world"}');
	assert.deepEqual(JSON.parse(output), input, 'matches original');
});