[fix] scroll to elements provided via URL hash

.changeset/wicked-plums-count.md

@@ -0,0 +1,5 @@
+---
+'@sveltejs/kit': patch
+---
+
+[fix] scroll to elements provided via URL hash

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

@@ -275,12 +275,17 @@ export class Renderer {
 			this._init(navigation_result);
 		}
 
-		if (opts) {
-			const { hash, scroll, keepfocus } = opts;
+		if (!opts?.keepfocus) {
+			document.body.focus();
+		}
 
-			if (!keepfocus) {
-				document.body.focus();
-			}
+		await 0;
+
+		// After `await 0`, the onMount() function in the component executed.
+		// If there was no scrolling happening (checked via pageYOffset),
+		// continue on our custom scroll handling
+		if (pageYOffset === 0 && opts) {
+			const { hash, scroll } = opts;
 
 			const deep_linked = hash && document.getElementById(hash.slice(1));
 			if (scroll) {
@@ -295,8 +300,6 @@ export class Renderer {
 			}
 		}
 
-		await 0;
-
 		this.loading.promise = null;
 		this.loading.id = null;
 

packages/kit/test/apps/basics/src/routes/anchor-with-manual-scroll/_tests.js

@@ -0,0 +1,31 @@
+import * as assert from 'uvu/assert';
+
+/**
+ * A suite of tests that checks that SvelteKit URL anchor is ignored when the
+ * onMount() lifecycle method contains custom scroll logic.
+ * @type {import('test').TestMaker}
+ */
+export default function (test) {
+	test(
+		'url-supplied anchor is ignored with onMount() scrolling on direct page load',
+		'/anchor-with-manual-scroll/anchor#go-to-element',
+		async ({ page, js }) => {
+			if (js) {
+				const p = await page.$('#abcde');
+				assert.ok(p && (await p.isVisible()));
+			}
+		}
+	);
+
+	test(
+		'url-supplied anchor is ignored with onMount() scrolling on navigation to page',
+		'/anchor-with-manual-scroll',
+		async ({ page, clicknav, js }) => {
+			await clicknav('[href="/anchor-with-manual-scroll/anchor#go-to-element"]');
+			if (js) {
+				const p = await page.$('#abcde');
+				assert.ok(p && (await p.isVisible()));
+			}
+		}
+	);
+}

packages/kit/test/apps/basics/src/routes/anchor-with-manual-scroll/anchor.svelte

@@ -0,0 +1,20 @@
+<script>
+	import { onMount } from 'svelte';
+
+	onMount(() => {
+		document.getElementById('abcde')?.scrollIntoView();
+	});
+</script>
+
+<div>They (don't) see me...</div>
+<div style="background-color: peru;">
+	<p id="go-to-element">The browser scrolls to me</p>
+</div>
+<p id="abcde">I take precedence</p>
+
+<style>
+	div {
+		background-color: hotpink;
+		height: 180vh;
+	}
+</style>

packages/kit/test/apps/basics/src/routes/anchor-with-manual-scroll/index.svelte

@@ -0,0 +1,15 @@
+<h1>Welcome to a test project</h1>
+<a href="/anchor-with-manual-scroll/anchor#go-to-element">Anchor demo</a>
+
+<style>
+	:global(body) {
+		background-color: tan;
+		display: flex;
+		flex-direction: column;
+	}
+
+	a {
+		display: block;
+		margin: 20px;
+	}
+</style>

packages/kit/test/apps/basics/src/routes/anchor/_tests.js

@@ -0,0 +1,31 @@
+import * as assert from 'uvu/assert';
+
+/**
+ * A suite of tests that checks that SvelteKit URL anchor is respected and the
+ * element with the anchor ID is scrolled into view.
+ * @type {import('test').TestMaker}
+ */
+export default function (test) {
+	test(
+		'url-supplied anchor works on direct page load',
+		'/anchor/anchor#go-to-element',
+		async ({ page, js }) => {
+			if (js) {
+				const p = await page.$('#go-to-element');
+				assert.ok(p && (await p.isVisible()));
+			}
+		}
+	);
+
+	test(
+		'url-supplied anchor works on navigation to page',
+		'/anchor',
+		async ({ page, clicknav, js }) => {
+			await clicknav('[href="/anchor/anchor#go-to-element"]');
+			if (js) {
+				const p = await page.$('#go-to-element');
+				assert.ok(p && (await p.isVisible()));
+			}
+		}
+	);
+}

packages/kit/test/apps/basics/src/routes/anchor/anchor.svelte

@@ -0,0 +1,11 @@
+<div>They (don't) see me...</div>
+<div style="background-color: peru;">
+	<p id="go-to-element">The browser scrolls to me</p>
+</div>
+
+<style>
+	div {
+		background-color: hotpink;
+		height: 180vh;
+	}
+</style>

packages/kit/test/apps/basics/src/routes/anchor/index.svelte

@@ -0,0 +1,15 @@
+<h1>Welcome to a test project</h1>
+<a href="/anchor/anchor#go-to-element">Anchor demo</a>
+
+<style>
+	:global(body) {
+		background-color: tan;
+		display: flex;
+		flex-direction: column;
+	}
+
+	a {
+		display: block;
+		margin: 20px;
+	}
+</style>

packages/kit/test/apps/basics/src/routes/use-action/_tests.js

@@ -12,7 +12,7 @@ export default function (test) {
 		async ({ page, js }) => {
 			if (js) {
 				const input = await page.$('#input');
-				assert.ok(input && input.isVisible);
+				assert.ok(input && (await input.isVisible()));
 				assert.ok(await page.$eval('#input', (el) => el === document.activeElement));
 			}
 		}
@@ -25,7 +25,7 @@ export default function (test) {
 			await clicknav('[href="/use-action/focus-and-scroll"]');
 			if (js) {
 				const input = await page.$('#input');
-				assert.ok(input && input.isVisible);
+				assert.ok(input && (await input.isVisible()));
 				assert.ok(await page.$eval('#input', (el) => el === document.activeElement));
 			}
 		}