add error message if source doesn't exist, cleanup code

documentation/docs/02-runes/02-$state.md

@@ -184,7 +184,7 @@ In the case that you aren't using a proxied `$state` via use of `$state.raw` or
 </button>
 ```
 
-`$state.invalidate` can also be used with reactive class fields:
+`$state.invalidate` can also be used with reactive class fields, and properties of `$state` objects:
 
 ```js
 class Box {
@@ -199,10 +199,17 @@ class Counter {
 	count = $state(new Box(0));
 
 	increment() {
-		this.count.value++;
+		this.count.value += 1;
 		$state.invalidate(this.count);
 	}
 }
+
+let counter = $state({count: new Box(0)});
+
+function increment() {
+	counter.count.value += 1;
+	$state.invalidate(counter.count);
+}
 ```
 
 ## Passing state into functions

documentation/docs/98-reference/.generated/client-errors.md

@@ -116,6 +116,12 @@ The `%rune%` rune is only available inside `.svelte` and `.svelte.js/ts` files
 Property descriptors defined on `$state` objects must contain `value` and always be `enumerable`, `configurable` and `writable`.
 ```
 
+### state_invalidate_invalid_source
+
+```
+The argument passed to `$state.invalidate` must be a variable or class field declared with `$state` or `$state.raw`, or a property of a `$state` object.
+```
+
 ### state_prototype_fixed
 
 ```

packages/svelte/messages/client-errors/errors.md

@@ -76,6 +76,10 @@ See the [migration guide](/docs/svelte/v5-migration-guide#Components-are-no-long
 
 > Property descriptors defined on `$state` objects must contain `value` and always be `enumerable`, `configurable` and `writable`.
 
+## state_invalidate_invalid_source
+
+> The argument passed to `$state.invalidate` must be a variable or class field declared with `$state` or `$state.raw`, or a property of a `$state` object.
+
 ## state_prototype_fixed
 
 > Cannot set prototype of `$state` object

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

@@ -1,17 +1,31 @@
-/** @import { CallExpression, Expression, Identifier } from 'estree' */
+/** @import { CallExpression, Expression, Identifier, MemberExpression, Node } from 'estree' */
 /** @import { Context } from '../types' */
 import { dev, is_ignored } from '../../../../state.js';
 import * as b from '../../../../utils/builders.js';
 import { get_rune } from '../../../scope.js';
 import { transform_inspect_rune } from '../../utils.js';
 import * as e from '../../../../errors.js';
-import { object } from '../../../../utils/ast.js';
 
 /**
  * @param {CallExpression} node
  * @param {Context} context
  */
 export function CallExpression(node, context) {
+	/**
+	 * Some nodes that get replaced should keep their locations (for better source maps and such)
+	 * @template {Node} N
+	 * @param {N} node
+	 * @param {N} replacement
+	 * @returns {N}
+	 */
+	function attach_locations(node, replacement) {
+		return {
+			...replacement,
+			start: node.start,
+			end: node.end,
+			loc: node.loc
+		};
+	}
 	switch (get_rune(node, context.state.scope)) {
 		case '$host':
 			return b.id('$$props.$$host');
@@ -28,11 +42,13 @@ export function CallExpression(node, context) {
 		/* eslint-disable no-fallthrough */
 		case '$state.invalidate':
 			if (node.arguments[0].type === 'Identifier') {
-				return b.call('$.invalidate', node.arguments[0]);
+				return b.call(
+					attach_locations(/** @type {Expression} */ (node.callee), b.id('$.invalidate')),
+					node.arguments[0]
+				);
 			} else if (node.arguments[0].type === 'MemberExpression') {
-				const { object: obj, property } = node.arguments[0];
-				const root = object(node.arguments[0]);
-				if (obj.type === 'ThisExpression') {
+				const { object, property } = node.arguments[0];
+				if (object.type === 'ThisExpression') {
 					let field;
 					switch (property.type) {
 						case 'Identifier':
@@ -45,17 +61,26 @@ export function CallExpression(node, context) {
 					if (!field || (field.kind !== 'state' && field.kind !== 'raw_state')) {
 						e.state_invalidate_nonreactive_argument(node);
 					}
-					return b.call('$.invalidate', b.member(b.this, field.id));
+					return b.call(
+						attach_locations(/** @type {Expression} */ (node.callee), b.id('$.invalidate')),
+						attach_locations(node.arguments[0], b.member(object, field.id))
+					);
 				}
 				/** @type {Expression[]} */
 				const source_args = /** @type {Expression[]} */ ([
-					context.visit(obj),
+					context.visit(object),
 					node.arguments[0].computed
 						? context.visit(property)
 						: b.literal(/** @type {Identifier} */ (property).name)
 				]);
 				const arg = b.call('$.lookup_source', ...source_args);
-				return b.call('$.invalidate', arg);
+				return b.call(
+					attach_locations(/** @type {Expression} */ (node.callee), b.id('$.invalidate')),
+					attach_locations(
+						/** @type {Expression} */ (node.arguments[0]),
+						/** @type {Expression} */ (arg)
+					)
+				);
 			}
 
 		case '$effect.root':

packages/svelte/src/internal/client/errors.js

@@ -291,6 +291,21 @@ export function state_descriptors_fixed() {
 	}
 }
 
+/**
+ * The argument passed to `$state.invalidate` must be a variable or class field declared with `$state` or `$state.raw`, or a property of a `$state` object.
+ * @returns {never}
+ */
+export function state_invalidate_invalid_source() {
+	if (DEV) {
+		const error = new Error(`state_invalidate_invalid_source\nThe argument passed to \`$state.invalidate\` must be a variable or class field declared with \`$state\` or \`$state.raw\`, or a property of a \`$state\` object.\nhttps://svelte.dev/e/state_invalidate_invalid_source`);
+
+		error.name = 'Svelte error';
+		throw error;
+	} else {
+		throw new Error(`https://svelte.dev/e/state_invalidate_invalid_source`);
+	}
+}
+
 /**
  * Cannot set prototype of `$state` object
  * @returns {never}

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

@@ -224,8 +224,8 @@ export function internal_set(source, value) {
  * @param {Source | null} source
  */
 export function invalidate(source) {
-	if (source === null) {
-		return;
+	if (source === null || (source.f & DERIVED) !== 0) {
+		e.state_invalidate_invalid_source();
 	}
 	if (
 		active_reaction !== null &&