From 0a7de87eb5ef0e825145c82d20e70984ee71dada Mon Sep 17 00:00:00 2001
From: Dominic Gannaway <trueadm@users.noreply.github.com>
Date: Mon, 3 Jun 2024 11:04:58 +0100
Subject: [PATCH] fix: address map reactivity regression (#11882)

---
 .changeset/lovely-zebras-own.md            |  5 +++++
 packages/svelte/src/reactivity/map.js      | 11 ++++++++--
 packages/svelte/src/reactivity/map.test.ts | 25 +++++++++++++++++++++-
 3 files changed, 38 insertions(+), 3 deletions(-)
 create mode 100644 .changeset/lovely-zebras-own.md

diff --git a/.changeset/lovely-zebras-own.md b/.changeset/lovely-zebras-own.md
new file mode 100644
index 0000000000..e41c6dcb9e
--- /dev/null
+++ b/.changeset/lovely-zebras-own.md
@@ -0,0 +1,5 @@
+---
+"svelte": patch
+---
+
+fix: address map reactivity regression
diff --git a/packages/svelte/src/reactivity/map.js b/packages/svelte/src/reactivity/map.js
index ece3d1845d..400f607083 100644
--- a/packages/svelte/src/reactivity/map.js
+++ b/packages/svelte/src/reactivity/map.js
@@ -140,18 +140,25 @@ export class ReactiveMap extends Map {
 		super.clear();
 	}
 
+	#read_all() {
+		get(this.#version);
+		for (var [, s] of this.#sources) {
+			get(s);
+		}
+	}
+
 	keys() {
 		get(this.#version);
 		return super.keys();
 	}
 
 	values() {
-		get(this.#version);
+		this.#read_all();
 		return super.values();
 	}
 
 	entries() {
-		get(this.#version);
+		this.#read_all();
 		return super.entries();
 	}
 
diff --git a/packages/svelte/src/reactivity/map.test.ts b/packages/svelte/src/reactivity/map.test.ts
index 3cdba4bb38..6dda7bf802 100644
--- a/packages/svelte/src/reactivity/map.test.ts
+++ b/packages/svelte/src/reactivity/map.test.ts
@@ -36,7 +36,30 @@ test('map.values()', () => {
 		map.clear();
 	});
 
-	assert.deepEqual(log, [5, true, [1, 2, 3, 4, 5], 4, false, [1, 2, 4, 5], 0, false, []]);
+	flushSync(() => {
+		map.set(3, 3);
+	});
+
+	flushSync(() => {
+		map.set(3, 4);
+	});
+
+	assert.deepEqual(log, [
+		5,
+		true,
+		[1, 2, 3, 4, 5],
+		4,
+		false,
+		[1, 2, 4, 5],
+		0,
+		false,
+		[],
+		1,
+		true,
+		[3],
+		true,
+		[4]
+	]);
 
 	cleanup();
 });