From 945805a90a9336121ab4f0f8548437c0841339d0 Mon Sep 17 00:00:00 2001
From: Stephen Randall <stephen.randall@jhuapl.edu>
Date: Sun, 23 Feb 2025 03:50:19 -0500
Subject: [PATCH] hash routing fix

---
 .changeset/angry-peaches-beam.md                 |  5 +++++
 packages/kit/src/runtime/client/client.js        | 13 ++++++-------
 .../hash-based-routing/src/routes/+layout.svelte |  1 +
 .../test/apps/hash-based-routing/test/test.js    | 16 ++++++++++++++++
 4 files changed, 28 insertions(+), 7 deletions(-)
 create mode 100644 .changeset/angry-peaches-beam.md

diff --git a/.changeset/angry-peaches-beam.md b/.changeset/angry-peaches-beam.md
new file mode 100644
index 000000000000..8d7a8fd61546
--- /dev/null
+++ b/.changeset/angry-peaches-beam.md
@@ -0,0 +1,5 @@
+---
+'@sveltejs/kit': patch
+---
+
+fix: correct navigation history with hash router and ensure load functions are rerun on user changes to URL hash
diff --git a/packages/kit/src/runtime/client/client.js b/packages/kit/src/runtime/client/client.js
index 16cecc7fe092..042ea2b39ddf 100644
--- a/packages/kit/src/runtime/client/client.js
+++ b/packages/kit/src/runtime/client/client.js
@@ -2432,6 +2432,12 @@ function _start_router() {
 			if (!hash_navigating) {
 				const url = new URL(location.href);
 				update_url(url);
+
+				// if the user edits the hash via the browser URL bar, trigger a full-page
+				// reload to align with pathname router behavior
+				if (app.hash) {
+					location.reload();
+				}
 			}
 		}
 	});
@@ -2450,13 +2456,6 @@ function _start_router() {
 				'',
 				location.href
 			);
-		} else if (app.hash) {
-			// If the user edits the hash via the browser URL bar, it
-			// (surprisingly!) mutates `current.url`, allowing us to
-			// detect it and trigger a navigation
-			if (current.url.hash === location.hash) {
-				void navigate({ type: 'goto', url: decode_hash(current.url) });
-			}
 		}
 	});
 
diff --git a/packages/kit/test/apps/hash-based-routing/src/routes/+layout.svelte b/packages/kit/test/apps/hash-based-routing/src/routes/+layout.svelte
index 5ac801199106..76cae24dfaf8 100644
--- a/packages/kit/test/apps/hash-based-routing/src/routes/+layout.svelte
+++ b/packages/kit/test/apps/hash-based-routing/src/routes/+layout.svelte
@@ -9,6 +9,7 @@
 
 <a href="/">/</a>
 <a href="/#/a">/#/a</a>
+<a href="/#/b">/#/b</a>
 <a href="/#/a#b">/#/a#b</a>
 <a href="/#/b/123">/#/b/123</a>
 <a href="/#/b/456">/#/b/456</a>
diff --git a/packages/kit/test/apps/hash-based-routing/test/test.js b/packages/kit/test/apps/hash-based-routing/test/test.js
index 12589824e332..b9ab54dd1249 100644
--- a/packages/kit/test/apps/hash-based-routing/test/test.js
+++ b/packages/kit/test/apps/hash-based-routing/test/test.js
@@ -99,4 +99,20 @@ test.describe('hash based navigation', () => {
 		const url = new URL(page.url());
 		expect(url.hash).toBe('#/anchor#test');
 	});
+
+	test('navigation history works', async ({ page }) => {
+		await page.goto('/');
+
+		await page.locator('a[href="/#/a"]').click();
+		await page.waitForURL('/#/a');
+
+		await page.locator('a[href="/#/b"]').click();
+		await page.waitForURL('/#/b');
+
+		await page.goBack();
+		expect(page.locator('p')).toHaveText('a');
+
+		await page.goForward();
+		expect(page.locator('p')).toHaveText('b');
+	});
 });