prevent scroll when resetting page focus (#4065) (#4846)

* prevent scroll when resetting page focus

* changeset

Author: timothycohen

.changeset/olive-vans-talk.md

@@ -0,0 +1,5 @@
+---
+'@sveltejs/kit': patch
+---
+
+Fix Safari scroll bug on ssr:false page reload

packages/kit/src/runtime/client/client.js

@@ -299,7 +299,7 @@ export function create_client({ target, session, base, trailing_slash }) {
 
 				getSelection()?.removeAllRanges();
 				root.tabIndex = -1;
-				root.focus();
+				root.focus({ preventScroll: true });
 
 				// restore `tabindex` as to prevent `root` from stealing input from elements
 				if (tabindex !== null) {

packages/kit/test/apps/basics/src/routes/no-ssr/margin.svelte

@@ -0,0 +1,14 @@
+<div class="container">
+	<span> ^this is not the top of the screen</span>
+	<div class="spacer" />
+</div>
+
+<style>
+	.container {
+		margin-top: 300px;
+	}
+
+	.spacer {
+		height: 1000px;
+	}
+</style>

packages/kit/test/apps/basics/test/test.js

@@ -304,6 +304,13 @@ test.describe('Scrolling', () => {
 		await back();
 		expect(await page.evaluate(() => window.scrollY)).toBe(1000);
 	});
+
+	test('scroll position is top of page on ssr:false reload', async ({ page }) => {
+		await page.goto('/no-ssr/margin');
+		expect(await page.evaluate(() => window.scrollY)).toBe(0);
+		await page.reload();
+		expect(await page.evaluate(() => window.scrollY)).toBe(0);
+	});
 });
 
 test.describe.parallel('Imports', () => {