svelte/test/runtime/samples/dynamic-component-dirty/_config.js

const calls = [];
export default {
	get props() {
		return { calls };
	},

	before_test() {
		calls.length = 0;
	},

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

		assert.deepEqual(calls.length, 1);

		const event = new window.MouseEvent('click');
		await buttons.dispatchEvent(event);

		assert.deepEqual(calls.length, 1);

		component.current_path = 'bar';
		assert.deepEqual(calls.length, 2);
	}
};