fix never-expiring cache entries

packages/svelte/src/internal/client/reactivity/cache.js

@@ -1,7 +1,7 @@
 import { BaseCacheObserver } from '../../shared/cache-observer.js';
 import { ObservableCache } from '../../shared/observable-cache.js';
 import { tick } from '../runtime.js';
-import { render_effect } from './effects.js';
+import { get_effect_validation_error_code, render_effect } from './effects.js';
 
 /** @typedef {{ count: number, item: any }} Entry */
 /** @type {ObservableCache} */
@@ -18,8 +18,8 @@ export function cache(key, fn) {
 	const entry = client_cache.get(key);
 	const maybe_remove = create_remover(key);
 
-	let tracking = true;
-	try {
+	const tracking = get_effect_validation_error_code() === null;
+	if (tracking) {
 		render_effect(() => {
 			if (entry) entry.count++;
 			return () => {
@@ -29,8 +29,6 @@ export function cache(key, fn) {
 				maybe_remove(entry);
 			};
 		});
-	} catch {
-		tracking = false;
 	}
 
 	if (cached) {

packages/svelte/src/internal/client/reactivity/effects.js

@@ -48,17 +48,28 @@ import { without_reactive_context } from '../dom/elements/bindings/shared.js';
  * @param {'$effect' | '$effect.pre' | '$inspect'} rune
  */
 export function validate_effect(rune) {
+	const code = get_effect_validation_error_code();
+	if (code === null) return;
+	e[code](rune);
+}
+
+/**
+ * @returns {'effect_orphan' | 'effect_in_unowned_derived' | 'effect_in_teardown' | null}
+ */
+export function get_effect_validation_error_code() {
 	if (active_effect === null && active_reaction === null) {
-		e.effect_orphan(rune);
+		return 'effect_orphan';
 	}
 
 	if (active_reaction !== null && (active_reaction.f & UNOWNED) !== 0 && active_effect === null) {
-		e.effect_in_unowned_derived();
+		return 'effect_in_unowned_derived';
 	}
 
 	if (is_destroying_effect) {
-		e.effect_in_teardown(rune);
+		return 'effect_in_teardown';
 	}
+
+	return null;
 }
 
 /**