svelte/test/runtime/samples/key-block-array/_config.js

export default {
	html: '<div>1</div>',
	async test({ assert, component, target, window }) {
		let div = target.querySelector('div');
		await component.append(2);
		assert.htmlEqual(target.innerHTML, '<div>1,2</div>');
		assert.notStrictEqual(div, target.querySelector('div'));

		div = target.querySelector('div');

		component.array = [3, 4];
		assert.htmlEqual(target.innerHTML, '<div>3,4</div>');
		assert.notStrictEqual(div, target.querySelector('div'));
	}
};