fix

packages/svelte/src/compiler/phases/3-transform/client/transform-client.js

@@ -165,6 +165,7 @@ export function client_component(analysis, options) {
 		state_fields: new Map(),
 		transform: {},
 		in_constructor: false,
+		in_derived: false,
 		instance_level_snippets: [],
 		module_level_snippets: [],
 
@@ -703,6 +704,7 @@ export function client_module(analysis, options) {
 		state_fields: new Map(),
 		transform: {},
 		in_constructor: false,
+		in_derived: false,
 		is_instance: false
 	};
 

packages/svelte/src/compiler/phases/3-transform/client/types.d.ts

@@ -21,6 +21,11 @@ export interface ClientTransformState extends TransformState {
 	 */
 	readonly in_constructor: boolean;
 
+	/**
+	 * True if we're directly inside a `$derived(...)` expression (but not `$derived.by(...)`)
+	 */
+	readonly in_derived: boolean;
+
 	/** `true` if we're transforming the contents of `<script>` */
 	readonly is_instance: boolean;
 

packages/svelte/src/compiler/phases/3-transform/types.d.ts

@@ -8,8 +8,5 @@ export interface TransformState {
 	readonly scope: Scope;
 	readonly scopes: Map<AST.SvelteNode, Scope>;
 
-	/** True if we're directly inside a `$derived(...)` expression (but not `$derived.by(...)`) */
-	readonly in_derived: boolean;
-
 	readonly state_fields: Map<string, StateField>;
 }