fix: fix string name of reactive map and set iterator

.changeset/shy-fishes-drive.md

@@ -0,0 +1,5 @@
+---
+"svelte": patch
+---
+
+fix: fix string name of reactive map and set iterator

packages/svelte/src/reactivity/map.js

@@ -136,14 +136,15 @@ export class ReactiveMap extends Map {
 
 	values() {
 		get(this.#version);
-		return map(this.#sources.values(), get);
+		return map(this.#sources.values(), get, 'Map Iterator');
 	}
 
 	entries() {
 		get(this.#version);
 		return map(
 			this.#sources.entries(),
-			([key, source]) => /** @type {[K, V]} */ ([key, get(source)])
+			([key, source]) => /** @type {[K, V]} */ ([key, get(source)]),
+			'Map Iterator'
 		);
 	}
 

packages/svelte/src/reactivity/set.js

@@ -132,15 +132,15 @@ export class ReactiveSet extends Set {
 
 	keys() {
 		get(this.#version);
-		return this.#sources.keys();
+		return map(this.#sources.keys(), (key) => key, 'Set Iterator');
 	}
 
 	values() {
 		return this.keys();
 	}
 
 	entries() {
-		return map(this.keys(), (key) => /** @type {[T, T]} */ ([key, key]));
+		return map(this.keys(), (key) => /** @type {[T, T]} */ ([key, key]), 'Set Iterator');
 	}
 
 	[Symbol.iterator]() {

packages/svelte/src/reactivity/utils.js

@@ -3,9 +3,10 @@
  * @template U
  * @param {Iterable<T>} iterable
  * @param {(value: T) => U} fn
+ * @param {string} name
  * @returns {IterableIterator<U>}
  */
-export function map(iterable, fn) {
+export function map(iterable, fn, name) {
 	return {
 		[Symbol.iterator]: get_this,
 		next() {
@@ -14,6 +15,10 @@ export function map(iterable, fn) {
 			}
 
 			return { done: true, value: undefined };
+		},
+		// @ts-expect-error
+		get [Symbol.toStringTag]() {
+			return name;
 		}
 	};
 }

packages/svelte/tests/runtime-runes/samples/reactive-to-string/_config.js

@@ -0,0 +1,10 @@
+import { test } from '../../test';
+
+export default test({
+	html: `
+		<div>[object Set Iterator] [object Set Iterator] [object Set Iterator]</div>
+		<div>[object Set Iterator] [object Set Iterator] [object Set Iterator]</div>
+		<div>[object Map Iterator] [object Map Iterator] [object Map Iterator]</div>
+		<div>[object Map Iterator] [object Map Iterator] [object Map Iterator]</div>
+	`
+});

packages/svelte/tests/runtime-runes/samples/reactive-to-string/main.svelte

@@ -0,0 +1,13 @@
+<script>
+	import { Set as ReactiveSet, Map as ReactiveMap } from 'svelte/reactivity';
+
+	let map = new Map();
+	let set = new Set();
+	let rmap = new ReactiveMap();
+	let rset = new ReactiveSet();
+</script>
+
+<div>{rset.entries()} {rset.keys()} {rset.values()}</div>
+<div>{set.entries()} {set.keys()} {set.values()}</div>
+<div>{rmap.entries()} {rmap.keys()} {rmap.values()}</div>
+<div>{map.entries()} {map.keys()} {map.values()}</div>