Merge branch 'main' into customizable-select-for-real

.changeset/better-games-invite.md

@@ -1,5 +0,0 @@
----
-'svelte': patch
----
-
-fix: don't transform references of function declarations in legacy mode

.changeset/empty-paths-smile.md

@@ -1,5 +0,0 @@
----
-'svelte': patch
----
-
-fix: notify deriveds of changes to sources inside forks

.changeset/plenty-candies-notice.md

@@ -1,5 +0,0 @@
----
-'svelte': patch
----
-
-fix: prevent derives without dependencies from ever re-running

.changeset/seven-llamas-care.md

@@ -1,5 +0,0 @@
----
-'svelte': patch
----
-
-fix: correctly update writable deriveds inside forks

.changeset/spicy-years-stick.md

@@ -1,5 +0,0 @@
----
-'svelte': patch
----
-
-fix: remove `$inspect` calls after await expressions when compiling for production server code

.changeset/tall-clocks-turn.md

@@ -1,5 +0,0 @@
----
-'svelte': patch
----
-
-fix: clear batch between runs

.changeset/tall-phones-fix.md

@@ -1,5 +0,0 @@
----
-'svelte': patch
----
-
-fix: adjust `loc` property of `Program` nodes created from `<script>` elements

.changeset/thick-islands-pull.md

@@ -1,5 +0,0 @@
----
-'svelte': patch
----
-
-fix: don't revert source to UNINITIALIZED state when time travelling

packages/svelte/CHANGELOG.md

@@ -1,5 +1,35 @@
 # svelte
 
+## 5.46.3
+
+### Patch Changes
+
+- fix: reconnect clean deriveds when they are read in a reactive context ([#17362](https://github.com/sveltejs/svelte/pull/17362))
+
+- fix: don't transform references of function declarations in legacy mode ([#17431](https://github.com/sveltejs/svelte/pull/17431))
+
+- fix: notify deriveds of changes to sources inside forks ([#17437](https://github.com/sveltejs/svelte/pull/17437))
+
+- fix: always reconnect deriveds in get, when appropriate ([#17451](https://github.com/sveltejs/svelte/pull/17451))
+
+- fix: prevent derives without dependencies from ever re-running ([`286b40c4526ce9970cb81ddd5e65b93b722fe468`](https://github.com/sveltejs/svelte/commit/286b40c4526ce9970cb81ddd5e65b93b722fe468))
+
+- fix: correctly update writable deriveds inside forks ([#17437](https://github.com/sveltejs/svelte/pull/17437))
+
+- fix: remove `$inspect` calls after await expressions when compiling for production server code ([#17407](https://github.com/sveltejs/svelte/pull/17407))
+
+- fix: clear batch between runs ([#17424](https://github.com/sveltejs/svelte/pull/17424))
+
+- fix: adjust `loc` property of `Program` nodes created from `<script>` elements ([#17428](https://github.com/sveltejs/svelte/pull/17428))
+
+- fix: don't revert source to UNINITIALIZED state when time travelling ([#17409](https://github.com/sveltejs/svelte/pull/17409))
+
+## 5.46.2
+
+### Notice
+
+Not published due to CI issue
+
 ## 5.46.1
 
 ### Patch Changes

packages/svelte/package.json

@@ -2,7 +2,7 @@
   "name": "svelte",
   "description": "Cybernetically enhanced web apps",
   "license": "MIT",
-  "version": "5.46.1",
+  "version": "5.46.3",
   "type": "module",
   "types": "./types/index.d.ts",
   "engines": {

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

@@ -596,14 +596,14 @@ export function get(signal) {
 		}
 	}
 
-	if (is_destroying_effect) {
-		if (old_values.has(signal)) {
-			return old_values.get(signal);
-		}
+	if (is_destroying_effect && old_values.has(signal)) {
+		return old_values.get(signal);
+	}
 
-		if (is_derived) {
-			var derived = /** @type {Derived} */ (signal);
+	if (is_derived) {
+		var derived = /** @type {Derived} */ (signal);
 
+		if (is_destroying_effect) {
 			var value = derived.v;
 
 			// if the derived is dirty and has reactions, or depends on the values that just changed, re-execute
@@ -619,17 +619,28 @@ export function get(signal) {
 
 			return value;
 		}
-	} else if (
-		is_derived &&
-		(!batch_values?.has(signal) || (current_batch?.is_fork && !effect_tracking()))
-	) {
-		derived = /** @type {Derived} */ (signal);
+
+		// connect disconnected deriveds if we are reading them inside an effect,
+		// or inside another derived that is already connected
+		var should_connect =
+			(derived.f & CONNECTED) === 0 &&
+			!untracking &&
+			active_reaction !== null &&
+			(is_updating_effect || (active_reaction.f & CONNECTED) !== 0);
+
+		var is_new = derived.deps === null;
 
 		if (is_dirty(derived)) {
+			if (should_connect) {
+				// set the flag before `update_derived`, so that the derived
+				// is added as a reaction to its dependencies
+				derived.f |= CONNECTED;
+			}
+
 			update_derived(derived);
 		}
 
-		if (is_updating_effect && effect_tracking() && (derived.f & CONNECTED) === 0) {
+		if (should_connect && !is_new) {
 			reconnect(derived);
 		}
 	}
@@ -653,7 +664,7 @@ export function get(signal) {
 function reconnect(derived) {
 	if (derived.deps === null) return;
 
-	derived.f ^= CONNECTED;
+	derived.f |= CONNECTED;
 
 	for (const dep of derived.deps) {
 		(dep.reactions ??= []).push(derived);

packages/svelte/src/version.js

@@ -4,5 +4,5 @@
  * The current version, as set in package.json.
  * @type {string}
  */
-export const VERSION = '5.46.1';
+export const VERSION = '5.46.3';
 export const PUBLIC_VERSION = '5';

packages/svelte/tests/runtime-runes/samples/async-fork-snippet-dev/_config.js

@@ -0,0 +1,24 @@
+import { tick } from 'svelte';
+import { test } from '../../test';
+
+export default test({
+	compileOptions: {
+		dev: true
+	},
+
+	async test({ assert, target }) {
+		const [fork] = target.querySelectorAll('button');
+
+		fork.click();
+		await tick();
+
+		assert.htmlEqual(target.innerHTML, '<button>fork</button><button>false</button>');
+
+		const [, toggle] = target.querySelectorAll('button');
+
+		toggle.click();
+		await tick();
+
+		assert.htmlEqual(target.innerHTML, '<button>fork</button><button>true</button>');
+	}
+});

packages/svelte/tests/runtime-runes/samples/async-fork-snippet-dev/main.svelte

@@ -0,0 +1,26 @@
+<script>
+	import { fork } from 'svelte';
+
+	let condition = $state(false);
+	let checked = $state(false);
+
+	const d = $derived({ checked });
+</script>
+
+<button onclick={() => {
+	fork(() => {
+		condition = true;
+	}).commit();
+}}>fork</button>
+
+{#if condition}
+	<!-- in dev, snippet arguments are read eagerly, outside a tracking context -->
+	<!-- this test checks that doing so doesn't prevent the derived from connecting -->
+	{#snippet foo({ checked })}
+		{checked}
+	{/snippet}
+
+	<button onclick={() => (checked = !checked)}>
+		{@render foo(d)}
+	</button>
+{/if}

packages/svelte/tests/runtime-runes/samples/derived-read-outside-reaction/_config.js

@@ -0,0 +1,47 @@
+import { flushSync } from 'svelte';
+import { test } from '../../test';
+
+export default test({
+	html: `
+		<button>+1</button>
+		<button>add number</button>
+		<p>1, 2, 3</p>
+	`,
+
+	test({ assert, target }) {
+		const [button1, button2] = target.querySelectorAll('button');
+
+		button1.click();
+		flushSync();
+		assert.htmlEqual(
+			target.innerHTML,
+			`
+				<button>+1</button>
+				<button>add number</button>
+				<p>2, 4, 6</p>
+			`
+		);
+
+		button2.click();
+		flushSync();
+		assert.htmlEqual(
+			target.innerHTML,
+			`
+				<button>+1</button>
+				<button>add number</button>
+				<p>2, 4, 6, 8</p>
+			`
+		);
+
+		button1.click();
+		flushSync();
+		assert.htmlEqual(
+			target.innerHTML,
+			`
+				<button>+1</button>
+				<button>add number</button>
+				<p>3, 6, 9, 12</p>
+			`
+		);
+	}
+});

packages/svelte/tests/runtime-runes/samples/derived-read-outside-reaction/main.svelte

@@ -0,0 +1,30 @@
+<script lang="ts">
+	class Item {
+		product: number;
+
+		constructor(n: number) {
+			this.product = $derived(multiplier * n);
+		}
+	}
+
+	let numbers = $state([1, 2, 3]);
+	let multiplier = $state(1);
+
+	let items = $derived(numbers.map((n) => new Item(n)))
+	let products = $derived(items.map(item => item.product));
+</script>
+
+<button onclick={() => {
+	multiplier += 1;
+}}>+1</button>
+
+<button onclick={() => {
+	numbers.push(numbers.length + 1);
+
+	// this is load-bearing — by reading it outside a reaction, we recompute
+	// `products`, removing it as a reaction from `Item.product` dependencies,
+	// but we don't add it as a reaction to the new `Item.product` dependencies
+	products;
+}}>add number</button>
+
+<p>{products.join(', ')}</p>