use helper for combining window binding props

src/compile/render-dom/wrappers/Window.ts

@@ -3,6 +3,7 @@ import Block from '../Block';
 import Node from '../../nodes/shared/Node';
 import Wrapper from './shared/Wrapper';
 import deindent from '../../../utils/deindent';
+import stringifyProps from '../../../utils/stringifyProps';
 
 const associatedEvents = {
 	innerWidth: 'resize',
@@ -147,9 +148,7 @@ export default class WindowWrapper extends Wrapper {
 				`}
 				${component.options.dev && `component._updatingReadonlyProperty = true;`}
 
-				#component.set({
+				#component.set(${stringifyProps(props.map(prop => `${prop.name}: this.${prop.value}`))});
-					${props.map(prop => `${prop.name}: this.${prop.value},`)}
-				});
 
 				${component.options.dev && `component._updatingReadonlyProperty = false;`}
 				${event === 'scroll' && `${lock} = false;`}

test/js/samples/window-binding-scroll/expected.js

@@ -8,9 +8,7 @@ function create_main_fragment(component, ctx) {
 		if (window_updating) return;
 		window_updating = true;
 
-		component.set({
+		component.set({ y: this.pageYOffset });
-			y: this.pageYOffset
-		});
 		window_updating = false;
 	}
 	window.addEventListener("scroll", onwindowscroll);