svelte/test/runtime/samples/reactive-update-expression/_config.js

export default {
	html: `
	<button>+1</button>
	<p>count: 1</p>
	`,

	async test({ assert, component, target, window }) {
		const click = new window.MouseEvent('click');
		const button = target.querySelector('button');

		assert.equal(component.x, 1);

		await button.dispatchEvent(click);

		assert.equal(component.x, 3);
		assert.htmlEqual(target.innerHTML, `
			<button>+1</button>
			<p>count: 3</p>
		`);

		await button.dispatchEvent(click);

		assert.equal(component.x, 5);
		assert.htmlEqual(target.innerHTML, `
			<button>+1</button>
			<p>count: 5</p>
		`);
	}
};