uses setViewport (#4267)

components/alert/test/alert-toast.vdiff.js

@@ -1,5 +1,5 @@
 import { disableReducedMotionForTesting, restoreReducedMotionForTesting } from '../alert-toast.js';
-import { expect, fixture, focusElem, hoverElem, html, oneEvent } from '@brightspace-ui/testing';
+import { expect, fixture, focusElem, hoverElem, html, oneEvent, setViewport } from '@brightspace-ui/testing';
 import sinon from 'sinon';
 
 const alertWithSubtextAndCloseButton = html`
@@ -87,23 +87,17 @@ describe('alert-toast', () => {
 			await expect(document).to.be.golden();
 		});
 
-		/**
-		 * TODO: switch to more legitimate form of resizing once available
-		 */
 		it('resize smaller', async() => {
 			const elem = await fixture(multipleAlerts, { viewport });
 			await openAlerts(elem);
-			await fixture(html``, { viewport: { width: 300 } });
+			await setViewport({ width: 300 });
 			await expect(document).to.be.golden();
 		});
 
-		/**
-		 * TODO: switch to more legitimate form of resizing once available
-		 */
 		it('resize larger', async() => {
 			const elem = await fixture(multipleAlerts, { viewport: { width: 300, height: 400 } });
 			await openAlerts(elem);
-			await fixture(html``, { viewport: { width: 700 } });
+			await setViewport({ width: 700 });
 			await expect(document).to.be.golden();
 		});