Merge remote-tracking branch 'upstream/main' into $state-invalidate

Author: Ocean-OS

.changeset/nervous-kids-shake.md

@@ -4,7 +4,7 @@ title: .svelte.js and .svelte.ts files
 
 Besides `.svelte` files, Svelte also operates on `.svelte.js` and `.svelte.ts` files.
 
-These behave like any other `.js` or `.ts` module, except that you can use runes. This is useful for creating reusable reactive logic, or sharing reactive state across your app.
+These behave like any other `.js` or `.ts` module, except that you can use runes. This is useful for creating reusable reactive logic, or sharing reactive state across your app (though note that you [cannot export reassigned state]($state#Passing-state-across-modules)).
 
 > [!LEGACY]
 > This is a concept that didn't exist prior to Svelte 5

.changeset/stupid-vans-draw.md

@@ -291,3 +291,83 @@ console.log(total.value); // 7
 ```
 
 ...though if you find yourself writing code like that, consider using [classes](#Classes) instead.
+
+## Passing state across modules
+
+You can declare state in `.svelte.js` and `.svelte.ts` files, but you can only _export_ that state if it's not directly reassigned. In other words you can't do this:
+
+```js
+/// file: state.svelte.js
+export let count = $state(0);
+
+export function increment() {
+	count += 1;
+}
+```
+
+That's because every reference to `count` is transformed by the Svelte compiler — the code above is roughly equivalent to this:
+
+```js
+/// file: state.svelte.js (compiler output)
+// @filename: index.ts
+interface Signal<T> {
+	value: T;
+}
+
+interface Svelte {
+	state<T>(value?: T): Signal<T>;
+	get<T>(source: Signal<T>): T;
+	set<T>(source: Signal<T>, value: T): void;
+}
+declare const $: Svelte;
+// ---cut---
+export let count = $.state(0);
+
+export function increment() {
+	$.set(count, $.get(count) + 1);
+}
+```
+
+> [!NOTE] You can see the code Svelte generates by clicking the 'JS Output' tab in the [playground](/playground).
+
+Since the compiler only operates on one file at a time, if another file imports `count` Svelte doesn't know that it needs to wrap each reference in `$.get` and `$.set`:
+
+```js
+// @filename: state.svelte.js
+export let count = 0;
+
+// @filename: index.js
+// ---cut---
+import { count } from './state.svelte.js';
+
+console.log(typeof count); // 'object', not 'number'
+```
+
+This leaves you with two options for sharing state between modules — either don't reassign it...
+
+```js
+// This is allowed — since we're updating
+// `counter.count` rather than `counter`,
+// Svelte doesn't wrap it in `$.state`
+export const counter = $state({
+	count: 0
+});
+
+export function increment() {
+	counter.count += 1;
+}
+```
+
+...or don't directly export it:
+
+```js
+let count = $state(0);
+
+export function getCount() {
+	return count;
+}
+
+export function increment() {
+	count += 1;
+}
+```

documentation/docs/01-introduction/04-svelte-js-files.md

@@ -21,7 +21,7 @@ A component is attempting to bind to a non-bindable property `%key%` belonging t
 ### component_api_changed
 
 ```
-%parent% called `%method%` on an instance of %component%, which is no longer valid in Svelte 5
+Calling `%method%` on a component instance (of %component%) is no longer valid in Svelte 5
 ```
 
 See the [migration guide](/docs/svelte/v5-migration-guide#Components-are-no-longer-classes) for more information.

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

@@ -1,5 +1,13 @@
 # svelte
 
+## 5.25.10
+
+### Patch Changes
+
+- fix: set deriveds as `CLEAN` if they are assigned to ([#15592](https://github.com/sveltejs/svelte/pull/15592))
+
+- fix: better scope `:global()` with nesting selector `&` ([#15671](https://github.com/sveltejs/svelte/pull/15671))
+
 ## 5.25.9
 
 ### Patch Changes

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

@@ -12,7 +12,7 @@
 
 ## component_api_changed
 
-> %parent% called `%method%` on an instance of %component%, which is no longer valid in Svelte 5
+> Calling `%method%` on a component instance (of %component%) is no longer valid in Svelte 5
 
 See the [migration guide](/docs/svelte/v5-migration-guide#Components-are-no-longer-classes) for more information.
 

packages/svelte/CHANGELOG.md

@@ -2,7 +2,7 @@
   "name": "svelte",
   "description": "Cybernetically enhanced web apps",
   "license": "MIT",
-  "version": "5.25.9",
+  "version": "5.25.10",
   "type": "module",
   "types": "./types/index.d.ts",
   "engines": {

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

@@ -536,9 +536,6 @@ export function client_component(analysis, options) {
 				b.assignment('=', b.member(b.id(analysis.name), '$.FILENAME', true), b.literal(filename))
 			)
 		);
-
-		body.unshift(b.stmt(b.call(b.id('$.mark_module_start'))));
-		body.push(b.stmt(b.call(b.id('$.mark_module_end'), b.id(analysis.name))));
 	}
 
 	if (!analysis.runes) {

packages/svelte/package.json

@@ -1,7 +1,6 @@
 import * as e from '../errors.js';
 import { component_context } from '../context.js';
 import { FILENAME } from '../../../constants.js';
-import { get_component } from './ownership.js';
 
 /** @param {Function & { [FILENAME]: string }} target */
 export function check_target(target) {
@@ -15,9 +14,7 @@ export function legacy_api() {
 
 	/** @param {string} method */
 	function error(method) {
-		// @ts-expect-error
-		const parent = get_component()?.[FILENAME] ?? 'Something';
-		e.component_api_changed(parent, method, component[FILENAME]);
+		e.component_api_changed(method, component[FILENAME]);
 	}
 
 	return {