From eedb59355f7c0051223272e9c3b2249433e0f473 Mon Sep 17 00:00:00 2001
From: Dominic Gannaway <trueadm@users.noreply.github.com>
Date: Tue, 5 Mar 2024 12:51:02 +0000
Subject: [PATCH] fix: adjust keyed each block equality handling (#10699)

Fixes #10685
---
 .changeset/seven-masks-end.md                 |  5 +++++
 .../src/internal/client/dom/blocks/each.js    |  8 +++++--
 .../samples/each-updates-4/_config.js         | 21 +++++++++++++++++++
 .../samples/each-updates-4/main.svelte        | 13 ++++++++++++
 4 files changed, 45 insertions(+), 2 deletions(-)
 create mode 100644 .changeset/seven-masks-end.md
 create mode 100644 packages/svelte/tests/runtime-runes/samples/each-updates-4/_config.js
 create mode 100644 packages/svelte/tests/runtime-runes/samples/each-updates-4/main.svelte

diff --git a/.changeset/seven-masks-end.md b/.changeset/seven-masks-end.md
new file mode 100644
index 0000000000..342091267d
--- /dev/null
+++ b/.changeset/seven-masks-end.md
@@ -0,0 +1,5 @@
+---
+"svelte": patch
+---
+
+fix: adjust keyed each block equality handling
diff --git a/packages/svelte/src/internal/client/dom/blocks/each.js b/packages/svelte/src/internal/client/dom/blocks/each.js
index f84d2a7d02..c50f959406 100644
--- a/packages/svelte/src/internal/client/dom/blocks/each.js
+++ b/packages/svelte/src/internal/client/dom/blocks/each.js
@@ -20,8 +20,8 @@ import { current_block, destroy_signal, execute_effect, push_destroy_fn } from '
 import { render_effect } from '../../reactivity/effects.js';
 import { source, mutable_source, set } from '../../reactivity/sources.js';
 import { trigger_transitions } from '../../transitions.js';
-import { is_array } from '../../utils.js';
-import { EACH_BLOCK, EACH_ITEM_BLOCK } from '../../constants.js';
+import { is_array, is_frozen } from '../../utils.js';
+import { EACH_BLOCK, EACH_ITEM_BLOCK, STATE_SYMBOL } from '../../constants.js';
 
 const NEW_BLOCK = -1;
 const MOVED_BLOCK = 99999999;
@@ -449,6 +449,10 @@ function reconcile_tracked_array(
 	apply_transitions,
 	keys
 ) {
+	// If we are working with an array that isn't proxied or frozen, then remove strict equality.
+	if ((flags & EACH_IS_STRICT_EQUALS) !== 0 && !is_frozen(array) && !(STATE_SYMBOL in array)) {
+		flags ^= EACH_IS_STRICT_EQUALS;
+	}
 	var a_blocks = each_block.v;
 	const is_computed_key = keys !== null;
 	var active_transitions = each_block.s;
diff --git a/packages/svelte/tests/runtime-runes/samples/each-updates-4/_config.js b/packages/svelte/tests/runtime-runes/samples/each-updates-4/_config.js
new file mode 100644
index 0000000000..284f036dc4
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/each-updates-4/_config.js
@@ -0,0 +1,21 @@
+import { flushSync } from 'svelte';
+import { test } from '../../test';
+
+export default test({
+	html: `100\n<button>Update</button>`,
+
+	async test({ assert, target }) {
+		/**
+		 * @type {{ click: () => void; }}
+		 */
+		let btn1;
+
+		[btn1] = target.querySelectorAll('button');
+
+		flushSync(() => {
+			btn1.click();
+		});
+
+		assert.htmlEqual(target.innerHTML, `1000\n<button>Update</button>`);
+	}
+});
diff --git a/packages/svelte/tests/runtime-runes/samples/each-updates-4/main.svelte b/packages/svelte/tests/runtime-runes/samples/each-updates-4/main.svelte
new file mode 100644
index 0000000000..f48f711976
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/each-updates-4/main.svelte
@@ -0,0 +1,13 @@
+<script>
+	import { writable } from "svelte/store";
+
+	const roomState = writable({
+		users: {"gary": { name: "gary", value: 100 }},
+	});
+</script>
+
+{#each Object.values($roomState.users) as user (user.name)}
+	{user.value}
+{/each}
+
+<button onclick={() => $roomState.users["gary"].value = 1000}>Update</button>