svelte/test/runtime/samples/component-event-handler-modifier-once-dynamic/_config.js

export default {
	html: `
		<button>update handler</button>
		<button>0</button>
	`,

	async test({ assert, component, target, window }) {
		const [updateButton, button] = target.querySelectorAll('button');
		const event = new window.MouseEvent('click');

		await updateButton.dispatchEvent(event);
		await button.dispatchEvent(event);
		assert.equal(component.count, 10);

		await button.dispatchEvent(event);
		assert.equal(component.count, 10);
	}
};