fix: ensure $inspect works with SvelteMap and SvelteSet (#12994)

* fix: ensure $inspect works with SvelteMap and SvelteSet

* build

* dev only

* dev only

* lint

* lint

* lint

* alternative

* Update packages/svelte/src/reactivity/map.js

---------

Co-authored-by: Rich Harris <rich.harris@vercel.com>

.changeset/green-baboons-sip.md

@@ -0,0 +1,5 @@
+---
+'svelte': patch
+---
+
+fix: ensure $inspect works with SvelteMap and SvelteSet

packages/svelte/src/internal/shared/clone.js

@@ -56,6 +56,9 @@ function clone(value, cloned, path, paths) {
 		const unwrapped = cloned.get(value);
 		if (unwrapped !== undefined) return unwrapped;
 
+		if (value instanceof Map) return /** @type {Snapshot<T>} */ (new Map(value));
+		if (value instanceof Set) return /** @type {Snapshot<T>} */ (new Set(value));
+
 		if (is_array(value)) {
 			const copy = /** @type {Snapshot<any>} */ ([]);
 			cloned.set(value, copy);

packages/svelte/tests/runtime-runes/samples/inspect-map-set/_config.js

@@ -0,0 +1,26 @@
+import { flushSync } from 'svelte';
+import { test } from '../../test';
+
+export default test({
+	compileOptions: {
+		dev: true
+	},
+
+	async test({ assert, target, logs }) {
+		const [btn, btn2] = target.querySelectorAll('button');
+		btn.click();
+		btn2.click();
+		flushSync();
+
+		assert.deepEqual(logs, [
+			'init',
+			new Map(),
+			'init',
+			new Set(),
+			'update',
+			new Map([['a', 'a']]),
+			'update',
+			new Set(['a'])
+		]);
+	}
+});

packages/svelte/tests/runtime-runes/samples/inspect-map-set/main.svelte

@@ -0,0 +1,12 @@
+<script>
+	import { SvelteMap, SvelteSet } from 'svelte/reactivity';
+
+	let map = new SvelteMap();
+	let set = new SvelteSet();
+
+	$inspect(map);
+	$inspect(set);
+</script>
+
+<button onclick={() => map.set('a', 'a')}>Map</button>
+<button onclick={() => set.add('a')}>Set</button>