better

src/internal/scheduler.js

@@ -10,7 +10,8 @@ const render_callbacks = [];
 
 export function schedule_update() {
 	if (!update_promise) {
-		update_promise = Promise.resolve().then(flush);
+		update_promise = Promise.resolve();
+		update_promise.then(flush);
 	}
 }
 

test/runtime/samples/lifecycle-next-tick/_config.js

@@ -3,13 +3,13 @@ export default {
 		const buttons = target.querySelectorAll('button');
 		const click = new window.MouseEvent('click');
 
-		await (await buttons[0].dispatchEvent(click));
+		await buttons[0].dispatchEvent(click);
 		assert.deepEqual(component.snapshots, [
 			'before 0',
 			'after 1'
 		]);
 
-		await (await buttons[0].dispatchEvent(click));
+		await buttons[0].dispatchEvent(click);
 		assert.deepEqual(component.snapshots, [
 			'before 0',
 			'after 1',
@@ -17,7 +17,7 @@ export default {
 			'after 2'
 		]);
 
-		await (await buttons[1].dispatchEvent(click));
+		await buttons[1].dispatchEvent(click);
 		assert.deepEqual(component.snapshots, [
 			'before 0',
 			'after 1',