From 0bba84cc203c7cab945527cc3928597d3612a37d Mon Sep 17 00:00:00 2001
From: Bladesheng <keadr23@gmail.com>
Date: Fri, 25 Jul 2025 14:43:41 +0200
Subject: [PATCH 1/9] fix: add types for `part` attribute to svg attributes
 (#16499)

---
 .changeset/seven-colts-obey.md | 5 +++++
 packages/svelte/elements.d.ts  | 1 +
 2 files changed, 6 insertions(+)
 create mode 100644 .changeset/seven-colts-obey.md

diff --git a/.changeset/seven-colts-obey.md b/.changeset/seven-colts-obey.md
new file mode 100644
index 000000000000..b41216f64908
--- /dev/null
+++ b/.changeset/seven-colts-obey.md
@@ -0,0 +1,5 @@
+---
+'svelte': patch
+---
+
+fix: add types for `part` attribute to svg attributes
diff --git a/packages/svelte/elements.d.ts b/packages/svelte/elements.d.ts
index 604241592aff..2e1042dfd6b8 100644
--- a/packages/svelte/elements.d.ts
+++ b/packages/svelte/elements.d.ts
@@ -1553,6 +1553,7 @@ export interface SVGAttributes<T extends EventTarget> extends AriaAttributes, DO
 	height?: number | string | undefined | null;
 	id?: string | undefined | null;
 	lang?: string | undefined | null;
+	part?: string | undefined | null;
 	max?: number | string | undefined | null;
 	media?: string | undefined | null;
 	// On the `textPath` element

From b0f9ea3ae62cfb9eb4437898bf8a6b90e0531657 Mon Sep 17 00:00:00 2001
From: ComputerGuy <63362464+Ocean-OS@users.noreply.github.com>
Date: Fri, 25 Jul 2025 15:57:32 -0700
Subject: [PATCH 2/9] fix: throw on duplicate class field declarations (#16502)

* fix: throw on duplicate class field declarations

* doh

* handle assignment in constructor

* fix

* apply suggestion from review

* fix

* fix failing test
---
 .changeset/odd-phones-taste.md                |  5 ++
 .../98-reference/.generated/compile-errors.md |  6 +++
 .../svelte/messages/compile-errors/script.md  |  4 ++
 packages/svelte/src/compiler/errors.js        | 10 ++++
 .../phases/2-analyze/visitors/ClassBody.js    | 53 ++++++++++++++++++-
 .../class-state-constructor-9/errors.json     | 12 ++---
 6 files changed, 82 insertions(+), 8 deletions(-)
 create mode 100644 .changeset/odd-phones-taste.md

diff --git a/.changeset/odd-phones-taste.md b/.changeset/odd-phones-taste.md
new file mode 100644
index 000000000000..ec9534b74157
--- /dev/null
+++ b/.changeset/odd-phones-taste.md
@@ -0,0 +1,5 @@
+---
+'svelte': patch
+---
+
+fix: throw on duplicate class field declarations
diff --git a/documentation/docs/98-reference/.generated/compile-errors.md b/documentation/docs/98-reference/.generated/compile-errors.md
index 20f57770d122..957a9f67c7b0 100644
--- a/documentation/docs/98-reference/.generated/compile-errors.md
+++ b/documentation/docs/98-reference/.generated/compile-errors.md
@@ -364,6 +364,12 @@ The $ name is reserved, and cannot be used for variables and imports
 The $ prefix is reserved, and cannot be used for variables and imports
 ```
 
+### duplicate_class_field
+
+```
+`%name%` has already been declared
+```
+
 ### each_item_invalid_assignment
 
 ```
diff --git a/packages/svelte/messages/compile-errors/script.md b/packages/svelte/messages/compile-errors/script.md
index 2b0c5eafdf86..5c1080acedfe 100644
--- a/packages/svelte/messages/compile-errors/script.md
+++ b/packages/svelte/messages/compile-errors/script.md
@@ -30,6 +30,10 @@
 
 > The $ prefix is reserved, and cannot be used for variables and imports
 
+## duplicate_class_field
+
+> `%name%` has already been declared
+
 ## each_item_invalid_assignment
 
 > Cannot reassign or bind to each block argument in runes mode. Use the array and index variables instead (e.g. `array[i] = value` instead of `entry = value`, or `bind:value={array[i]}` instead of `bind:value={entry}`)
diff --git a/packages/svelte/src/compiler/errors.js b/packages/svelte/src/compiler/errors.js
index 599d3e8248b0..e763a6e0733a 100644
--- a/packages/svelte/src/compiler/errors.js
+++ b/packages/svelte/src/compiler/errors.js
@@ -152,6 +152,16 @@ export function dollar_prefix_invalid(node) {
 	e(node, 'dollar_prefix_invalid', `The $ prefix is reserved, and cannot be used for variables and imports\nhttps://svelte.dev/e/dollar_prefix_invalid`);
 }
 
+/**
+ * `%name%` has already been declared
+ * @param {null | number | NodeLike} node
+ * @param {string} name
+ * @returns {never}
+ */
+export function duplicate_class_field(node, name) {
+	e(node, 'duplicate_class_field', `\`${name}\` has already been declared\nhttps://svelte.dev/e/duplicate_class_field`);
+}
+
 /**
  * Cannot reassign or bind to each block argument in runes mode. Use the array and index variables instead (e.g. `array[i] = value` instead of `entry = value`, or `bind:value={array[i]}` instead of `bind:value={entry}`)
  * @param {null | number | NodeLike} node
diff --git a/packages/svelte/src/compiler/phases/2-analyze/visitors/ClassBody.js b/packages/svelte/src/compiler/phases/2-analyze/visitors/ClassBody.js
index ffc39ac00de1..2bfc1dbce36c 100644
--- a/packages/svelte/src/compiler/phases/2-analyze/visitors/ClassBody.js
+++ b/packages/svelte/src/compiler/phases/2-analyze/visitors/ClassBody.js
@@ -33,6 +33,9 @@ export function ClassBody(node, context) {
 	/** @type {Map<string, StateField>} */
 	const state_fields = new Map();
 
+	/** @type {Map<string, Array<MethodDefinition['kind'] | 'prop' | 'assigned_prop'>>} */
+	const fields = new Map();
+
 	context.state.analysis.classes.set(node, state_fields);
 
 	/** @type {MethodDefinition | null} */
@@ -54,6 +57,14 @@ export function ClassBody(node, context) {
 				e.state_field_duplicate(node, name);
 			}
 
+			const _key = (key.type === 'PrivateIdentifier' ? '#' : '') + name;
+			const field = fields.get(_key);
+
+			// if there's already a method or assigned field, error
+			if (field && !(field.length === 1 && field[0] === 'prop')) {
+				e.duplicate_class_field(node, _key);
+			}
+
 			state_fields.set(name, {
 				node,
 				type: rune,
@@ -67,10 +78,48 @@ export function ClassBody(node, context) {
 	for (const child of node.body) {
 		if (child.type === 'PropertyDefinition' && !child.computed && !child.static) {
 			handle(child, child.key, child.value);
+			const key = (child.key.type === 'PrivateIdentifier' ? '#' : '') + get_name(child.key);
+			const field = fields.get(key);
+			if (!field) {
+				fields.set(key, [child.value ? 'assigned_prop' : 'prop']);
+				continue;
+			}
+			e.duplicate_class_field(child, key);
 		}
 
-		if (child.type === 'MethodDefinition' && child.kind === 'constructor') {
-			constructor = child;
+		if (child.type === 'MethodDefinition') {
+			if (child.kind === 'constructor') {
+				constructor = child;
+			} else if (!child.computed) {
+				const key = (child.key.type === 'PrivateIdentifier' ? '#' : '') + get_name(child.key);
+				const field = fields.get(key);
+				if (!field) {
+					fields.set(key, [child.kind]);
+					continue;
+				}
+				if (
+					field.includes(child.kind) ||
+					field.includes('prop') ||
+					field.includes('assigned_prop')
+				) {
+					e.duplicate_class_field(child, key);
+				}
+				if (child.kind === 'get') {
+					if (field.length === 1 && field[0] === 'set') {
+						field.push('get');
+						continue;
+					}
+				} else if (child.kind === 'set') {
+					if (field.length === 1 && field[0] === 'get') {
+						field.push('set');
+						continue;
+					}
+				} else {
+					field.push(child.kind);
+					continue;
+				}
+				e.duplicate_class_field(child, key);
+			}
 		}
 	}
 
diff --git a/packages/svelte/tests/validator/samples/class-state-constructor-9/errors.json b/packages/svelte/tests/validator/samples/class-state-constructor-9/errors.json
index b7dd4c8ed457..94b5f191c2f7 100644
--- a/packages/svelte/tests/validator/samples/class-state-constructor-9/errors.json
+++ b/packages/svelte/tests/validator/samples/class-state-constructor-9/errors.json
@@ -1,14 +1,14 @@
 [
 	{
-		"code": "state_field_invalid_assignment",
-		"message": "Cannot assign to a state field before its declaration",
+		"code": "duplicate_class_field",
+		"message": "`count` has already been declared",
 		"start": {
-			"line": 2,
-			"column": 1
+			"line": 5,
+			"column": 2
 		},
 		"end": {
-			"line": 2,
-			"column": 12
+			"line": 5,
+			"column": 24
 		}
 	}
 ]

From d0ebd42986c4d3e4db0420f1aaebd337afdb230f Mon Sep 17 00:00:00 2001
From: "github-actions[bot]"
 <41898282+github-actions[bot]@users.noreply.github.com>
Date: Fri, 25 Jul 2025 16:46:12 -0700
Subject: [PATCH 3/9] Version Packages (#16500)

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>
---
 .changeset/odd-phones-taste.md | 5 -----
 .changeset/seven-colts-obey.md | 5 -----
 packages/svelte/CHANGELOG.md   | 8 ++++++++
 packages/svelte/package.json   | 2 +-
 packages/svelte/src/version.js | 2 +-
 5 files changed, 10 insertions(+), 12 deletions(-)
 delete mode 100644 .changeset/odd-phones-taste.md
 delete mode 100644 .changeset/seven-colts-obey.md

diff --git a/.changeset/odd-phones-taste.md b/.changeset/odd-phones-taste.md
deleted file mode 100644
index ec9534b74157..000000000000
--- a/.changeset/odd-phones-taste.md
+++ /dev/null
@@ -1,5 +0,0 @@
----
-'svelte': patch
----
-
-fix: throw on duplicate class field declarations
diff --git a/.changeset/seven-colts-obey.md b/.changeset/seven-colts-obey.md
deleted file mode 100644
index b41216f64908..000000000000
--- a/.changeset/seven-colts-obey.md
+++ /dev/null
@@ -1,5 +0,0 @@
----
-'svelte': patch
----
-
-fix: add types for `part` attribute to svg attributes
diff --git a/packages/svelte/CHANGELOG.md b/packages/svelte/CHANGELOG.md
index 450ecde53b1e..766c83763acc 100644
--- a/packages/svelte/CHANGELOG.md
+++ b/packages/svelte/CHANGELOG.md
@@ -1,5 +1,13 @@
 # svelte
 
+## 5.36.17
+
+### Patch Changes
+
+- fix: throw on duplicate class field declarations ([#16502](https://github.com/sveltejs/svelte/pull/16502))
+
+- fix: add types for `part` attribute to svg attributes ([#16499](https://github.com/sveltejs/svelte/pull/16499))
+
 ## 5.36.16
 
 ### Patch Changes
diff --git a/packages/svelte/package.json b/packages/svelte/package.json
index 07954026b550..22bc8cc8fac6 100644
--- a/packages/svelte/package.json
+++ b/packages/svelte/package.json
@@ -2,7 +2,7 @@
   "name": "svelte",
   "description": "Cybernetically enhanced web apps",
   "license": "MIT",
-  "version": "5.36.16",
+  "version": "5.36.17",
   "type": "module",
   "types": "./types/index.d.ts",
   "engines": {
diff --git a/packages/svelte/src/version.js b/packages/svelte/src/version.js
index 5d76fc3f2963..d2992a3dcd8c 100644
--- a/packages/svelte/src/version.js
+++ b/packages/svelte/src/version.js
@@ -4,5 +4,5 @@
  * The current version, as set in package.json.
  * @type {string}
  */
-export const VERSION = '5.36.16';
+export const VERSION = '5.36.17';
 export const PUBLIC_VERSION = '5';

From c7851789d71cc3d0b5d89ce9c759a39be6caa51a Mon Sep 17 00:00:00 2001
From: 7nik <kifiranet@gmail.com>
Date: Sat, 26 Jul 2025 21:27:22 +0300
Subject: [PATCH 4/9] fix: always mark props as stateful (#16504)

---
 .changeset/gorgeous-jeans-begin.md                |  5 +++++
 .../phases/2-analyze/visitors/Identifier.js       |  5 ++++-
 .../props-default-value-function/_config.js       | 15 +++++++++++++++
 .../props-default-value-function/inner.svelte     |  4 ++++
 .../props-default-value-function/main.svelte      | 14 ++++++++++++++
 .../props-default-value-function/wrapper.svelte   |  7 +++++++
 .../props-default-value-function/wrapper2.svelte  |  7 +++++++
 7 files changed, 56 insertions(+), 1 deletion(-)
 create mode 100644 .changeset/gorgeous-jeans-begin.md
 create mode 100644 packages/svelte/tests/runtime-runes/samples/props-default-value-function/_config.js
 create mode 100644 packages/svelte/tests/runtime-runes/samples/props-default-value-function/inner.svelte
 create mode 100644 packages/svelte/tests/runtime-runes/samples/props-default-value-function/main.svelte
 create mode 100644 packages/svelte/tests/runtime-runes/samples/props-default-value-function/wrapper.svelte
 create mode 100644 packages/svelte/tests/runtime-runes/samples/props-default-value-function/wrapper2.svelte

diff --git a/.changeset/gorgeous-jeans-begin.md b/.changeset/gorgeous-jeans-begin.md
new file mode 100644
index 000000000000..586c4d8a57a3
--- /dev/null
+++ b/.changeset/gorgeous-jeans-begin.md
@@ -0,0 +1,5 @@
+---
+'svelte': patch
+---
+
+fix: always mark props as stateful
diff --git a/packages/svelte/src/compiler/phases/2-analyze/visitors/Identifier.js b/packages/svelte/src/compiler/phases/2-analyze/visitors/Identifier.js
index cced326f9baa..4dfdfe5af1a1 100644
--- a/packages/svelte/src/compiler/phases/2-analyze/visitors/Identifier.js
+++ b/packages/svelte/src/compiler/phases/2-analyze/visitors/Identifier.js
@@ -93,7 +93,10 @@ export function Identifier(node, context) {
 			context.state.expression.references.add(binding);
 			context.state.expression.has_state ||=
 				binding.kind !== 'static' &&
-				!binding.is_function() &&
+				(binding.kind === 'prop' ||
+					binding.kind === 'bindable_prop' ||
+					binding.kind === 'rest_prop' ||
+					!binding.is_function()) &&
 				!context.state.scope.evaluate(node).is_known;
 		}
 
diff --git a/packages/svelte/tests/runtime-runes/samples/props-default-value-function/_config.js b/packages/svelte/tests/runtime-runes/samples/props-default-value-function/_config.js
new file mode 100644
index 000000000000..6b281f04f0ee
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/props-default-value-function/_config.js
@@ -0,0 +1,15 @@
+import { flushSync } from 'svelte';
+import { test } from '../../test';
+
+export default test({
+	mode: ['client'],
+
+	test({ assert, target }) {
+		const btn = target.querySelector('button');
+
+		assert.htmlEqual(target.innerHTML, `<button>inc</button> Inner: 0 Inner: 0`);
+		btn?.click();
+		flushSync();
+		assert.htmlEqual(target.innerHTML, `<button>inc</button> Inner: 1 Inner: 1`);
+	}
+});
diff --git a/packages/svelte/tests/runtime-runes/samples/props-default-value-function/inner.svelte b/packages/svelte/tests/runtime-runes/samples/props-default-value-function/inner.svelte
new file mode 100644
index 000000000000..6bde0a15a87c
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/props-default-value-function/inner.svelte
@@ -0,0 +1,4 @@
+<script>
+	let { getter } = $props()
+</script>
+Inner: {getter()}
diff --git a/packages/svelte/tests/runtime-runes/samples/props-default-value-function/main.svelte b/packages/svelte/tests/runtime-runes/samples/props-default-value-function/main.svelte
new file mode 100644
index 000000000000..2cb2f67b82f7
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/props-default-value-function/main.svelte
@@ -0,0 +1,14 @@
+<script>
+	import Wrapper1 from "./wrapper.svelte"
+	import Wrapper2 from "./wrapper2.svelte"
+	let count = $state(0);
+
+	let getter = $derived.by(() => {
+		const copy = count;
+		return () => copy;
+	});
+</script>
+
+<button onclick={() => count++}>inc</button>
+<Wrapper1 {getter}/>
+<Wrapper2 {getter}/>
\ No newline at end of file
diff --git a/packages/svelte/tests/runtime-runes/samples/props-default-value-function/wrapper.svelte b/packages/svelte/tests/runtime-runes/samples/props-default-value-function/wrapper.svelte
new file mode 100644
index 000000000000..525494ddfbf1
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/props-default-value-function/wrapper.svelte
@@ -0,0 +1,7 @@
+<script >
+  import Inner from "./inner.svelte";
+
+  const { getter = () => -1} = $props();
+</script>
+
+<Inner {getter} />
diff --git a/packages/svelte/tests/runtime-runes/samples/props-default-value-function/wrapper2.svelte b/packages/svelte/tests/runtime-runes/samples/props-default-value-function/wrapper2.svelte
new file mode 100644
index 000000000000..9498f432d8ce
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/props-default-value-function/wrapper2.svelte
@@ -0,0 +1,7 @@
+<script >
+  import Inner from "./inner.svelte";
+
+  const { getter = $bindable(() => -1)} = $props();
+</script>
+
+<Inner {getter} />

From 7cc4d56263f724c4d76ab6140af4d117cbb41f1d Mon Sep 17 00:00:00 2001
From: Rich Harris <rich.harris@vercel.com>
Date: Sat, 26 Jul 2025 22:16:40 -0400
Subject: [PATCH 5/9] feat: ignore component options in `compileModule`
 (#16362)

---
 .changeset/violet-ways-sleep.md               |   5 +
 .../svelte/src/compiler/validate-options.js   | 172 +++++++++---------
 2 files changed, 96 insertions(+), 81 deletions(-)
 create mode 100644 .changeset/violet-ways-sleep.md

diff --git a/.changeset/violet-ways-sleep.md b/.changeset/violet-ways-sleep.md
new file mode 100644
index 000000000000..749ecb171960
--- /dev/null
+++ b/.changeset/violet-ways-sleep.md
@@ -0,0 +1,5 @@
+---
+'svelte': minor
+---
+
+feat: ignore component options in `compileModule`
diff --git a/packages/svelte/src/compiler/validate-options.js b/packages/svelte/src/compiler/validate-options.js
index ed83375d2236..2b727ad09335 100644
--- a/packages/svelte/src/compiler/validate-options.js
+++ b/packages/svelte/src/compiler/validate-options.js
@@ -8,7 +8,7 @@ import * as w from './warnings.js';
  * @typedef {(input: Input, keypath: string) => Required<Output>} Validator
  */
 
-const common = {
+const common_options = {
 	filename: string('(unknown)'),
 
 	// default to process.cwd() where it exists to replicate svelte4 behavior (and make Deno work with this as well)
@@ -48,110 +48,120 @@ const common = {
 	})
 };
 
-export const validate_module_options =
-	/** @type {Validator<ModuleCompileOptions, ValidatedModuleCompileOptions>} */ (
-		object({
-			...common
-		})
-	);
+const component_options = {
+	accessors: deprecate(w.options_deprecated_accessors, boolean(false)),
 
-export const validate_component_options =
-	/** @type {Validator<CompileOptions, ValidatedCompileOptions>} */ (
-		object({
-			...common,
+	css: validator('external', (input) => {
+		if (input === true || input === false) {
+			throw_error(
+				'The boolean options have been removed from the css option. Use "external" instead of false and "injected" instead of true'
+			);
+		}
+		if (input === 'none') {
+			throw_error(
+				'css: "none" is no longer a valid option. If this was crucial for you, please open an issue on GitHub with your use case.'
+			);
+		}
 
-			accessors: deprecate(w.options_deprecated_accessors, boolean(false)),
+		if (input !== 'external' && input !== 'injected') {
+			throw_error(`css should be either "external" (default, recommended) or "injected"`);
+		}
 
-			css: validator('external', (input) => {
-				if (input === true || input === false) {
-					throw_error(
-						'The boolean options have been removed from the css option. Use "external" instead of false and "injected" instead of true'
-					);
-				}
-				if (input === 'none') {
-					throw_error(
-						'css: "none" is no longer a valid option. If this was crucial for you, please open an issue on GitHub with your use case.'
-					);
-				}
+		return input;
+	}),
 
-				if (input !== 'external' && input !== 'injected') {
-					throw_error(`css should be either "external" (default, recommended) or "injected"`);
-				}
+	cssHash: fun(({ css, hash }) => {
+		return `svelte-${hash(css)}`;
+	}),
+
+	// TODO this is a sourcemap option, would be good to put under a sourcemap namespace
+	cssOutputFilename: string(undefined),
+
+	customElement: boolean(false),
+
+	discloseVersion: boolean(true),
 
-				return input;
-			}),
+	immutable: deprecate(w.options_deprecated_immutable, boolean(false)),
 
-			cssHash: fun(({ css, hash }) => {
-				return `svelte-${hash(css)}`;
-			}),
+	legacy: removed(
+		'The legacy option has been removed. If you are using this because of legacy.componentApi, use compatibility.componentApi instead'
+	),
+
+	compatibility: object({
+		componentApi: list([4, 5], 5)
+	}),
+
+	loopGuardTimeout: warn_removed(w.options_removed_loop_guard_timeout),
+
+	name: string(undefined),
 
-			// TODO this is a sourcemap option, would be good to put under a sourcemap namespace
-			cssOutputFilename: string(undefined),
+	namespace: list(['html', 'mathml', 'svg']),
 
-			customElement: boolean(false),
+	modernAst: boolean(false),
 
-			discloseVersion: boolean(true),
+	outputFilename: string(undefined),
 
-			immutable: deprecate(w.options_deprecated_immutable, boolean(false)),
+	preserveComments: boolean(false),
 
-			legacy: removed(
-				'The legacy option has been removed. If you are using this because of legacy.componentApi, use compatibility.componentApi instead'
-			),
+	fragments: list(['html', 'tree']),
 
-			compatibility: object({
-				componentApi: list([4, 5], 5)
-			}),
+	preserveWhitespace: boolean(false),
 
-			loopGuardTimeout: warn_removed(w.options_removed_loop_guard_timeout),
+	runes: boolean(undefined),
 
-			name: string(undefined),
+	hmr: boolean(false),
 
-			namespace: list(['html', 'mathml', 'svg']),
+	sourcemap: validator(undefined, (input) => {
+		// Source maps can take on a variety of values, including string, JSON, map objects from magic-string and source-map,
+		// so there's no good way to check type validity here
+		return input;
+	}),
 
-			modernAst: boolean(false),
+	enableSourcemap: warn_removed(w.options_removed_enable_sourcemap),
 
-			outputFilename: string(undefined),
+	hydratable: warn_removed(w.options_removed_hydratable),
 
-			preserveComments: boolean(false),
+	format: removed(
+		'The format option has been removed in Svelte 4, the compiler only outputs ESM now. Remove "format" from your compiler options. ' +
+			'If you did not set this yourself, bump the version of your bundler plugin (vite-plugin-svelte/rollup-plugin-svelte/svelte-loader)'
+	),
 
-			fragments: list(['html', 'tree']),
+	tag: removed(
+		'The tag option has been removed in Svelte 5. Use `<svelte:options customElement="tag-name" />` inside the component instead. ' +
+			'If that does not solve your use case, please open an issue on GitHub with details.'
+	),
 
-			preserveWhitespace: boolean(false),
+	sveltePath: removed(
+		'The sveltePath option has been removed in Svelte 5. ' +
+			'If this option was crucial for you, please open an issue on GitHub with your use case.'
+	),
 
-			runes: boolean(undefined),
+	// These two were primarily created for svelte-preprocess (https://github.com/sveltejs/svelte/pull/6194),
+	// but with new TypeScript compilation modes strictly separating types it's not necessary anymore
+	errorMode: removed(
+		'The errorMode option has been removed. If you are using this through svelte-preprocess with TypeScript, ' +
+			'use the https://www.typescriptlang.org/tsconfig#verbatimModuleSyntax setting instead'
+	),
 
-			hmr: boolean(false),
+	varsReport: removed(
+		'The vars option has been removed. If you are using this through svelte-preprocess with TypeScript, ' +
+			'use the https://www.typescriptlang.org/tsconfig#verbatimModuleSyntax setting instead'
+	)
+};
 
-			sourcemap: validator(undefined, (input) => {
-				// Source maps can take on a variety of values, including string, JSON, map objects from magic-string and source-map,
-				// so there's no good way to check type validity here
-				return input;
-			}),
+export const validate_module_options =
+	/** @type {Validator<ModuleCompileOptions, ValidatedModuleCompileOptions>} */ (
+		object({
+			...common_options,
+			...Object.fromEntries(Object.keys(component_options).map((key) => [key, () => {}]))
+		})
+	);
 
-			enableSourcemap: warn_removed(w.options_removed_enable_sourcemap),
-			hydratable: warn_removed(w.options_removed_hydratable),
-			format: removed(
-				'The format option has been removed in Svelte 4, the compiler only outputs ESM now. Remove "format" from your compiler options. ' +
-					'If you did not set this yourself, bump the version of your bundler plugin (vite-plugin-svelte/rollup-plugin-svelte/svelte-loader)'
-			),
-			tag: removed(
-				'The tag option has been removed in Svelte 5. Use `<svelte:options customElement="tag-name" />` inside the component instead. ' +
-					'If that does not solve your use case, please open an issue on GitHub with details.'
-			),
-			sveltePath: removed(
-				'The sveltePath option has been removed in Svelte 5. ' +
-					'If this option was crucial for you, please open an issue on GitHub with your use case.'
-			),
-			// These two were primarily created for svelte-preprocess (https://github.com/sveltejs/svelte/pull/6194),
-			// but with new TypeScript compilation modes strictly separating types it's not necessary anymore
-			errorMode: removed(
-				'The errorMode option has been removed. If you are using this through svelte-preprocess with TypeScript, ' +
-					'use the https://www.typescriptlang.org/tsconfig#verbatimModuleSyntax setting instead'
-			),
-			varsReport: removed(
-				'The vars option has been removed. If you are using this through svelte-preprocess with TypeScript, ' +
-					'use the https://www.typescriptlang.org/tsconfig#verbatimModuleSyntax setting instead'
-			)
+export const validate_component_options =
+	/** @type {Validator<CompileOptions, ValidatedCompileOptions>} */ (
+		object({
+			...common_options,
+			...component_options
 		})
 	);
 

From 39ee7cf4c247965ebacdd16fc365a31f00506026 Mon Sep 17 00:00:00 2001
From: "github-actions[bot]"
 <41898282+github-actions[bot]@users.noreply.github.com>
Date: Sat, 26 Jul 2025 22:22:14 -0700
Subject: [PATCH 6/9] Version Packages (#16505)

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>
---
 .changeset/gorgeous-jeans-begin.md |  5 -----
 .changeset/violet-ways-sleep.md    |  5 -----
 packages/svelte/CHANGELOG.md       | 10 ++++++++++
 packages/svelte/package.json       |  2 +-
 packages/svelte/src/version.js     |  2 +-
 5 files changed, 12 insertions(+), 12 deletions(-)
 delete mode 100644 .changeset/gorgeous-jeans-begin.md
 delete mode 100644 .changeset/violet-ways-sleep.md

diff --git a/.changeset/gorgeous-jeans-begin.md b/.changeset/gorgeous-jeans-begin.md
deleted file mode 100644
index 586c4d8a57a3..000000000000
--- a/.changeset/gorgeous-jeans-begin.md
+++ /dev/null
@@ -1,5 +0,0 @@
----
-'svelte': patch
----
-
-fix: always mark props as stateful
diff --git a/.changeset/violet-ways-sleep.md b/.changeset/violet-ways-sleep.md
deleted file mode 100644
index 749ecb171960..000000000000
--- a/.changeset/violet-ways-sleep.md
+++ /dev/null
@@ -1,5 +0,0 @@
----
-'svelte': minor
----
-
-feat: ignore component options in `compileModule`
diff --git a/packages/svelte/CHANGELOG.md b/packages/svelte/CHANGELOG.md
index 766c83763acc..f939f69d2804 100644
--- a/packages/svelte/CHANGELOG.md
+++ b/packages/svelte/CHANGELOG.md
@@ -1,5 +1,15 @@
 # svelte
 
+## 5.37.0
+
+### Minor Changes
+
+- feat: ignore component options in `compileModule` ([#16362](https://github.com/sveltejs/svelte/pull/16362))
+
+### Patch Changes
+
+- fix: always mark props as stateful ([#16504](https://github.com/sveltejs/svelte/pull/16504))
+
 ## 5.36.17
 
 ### Patch Changes
diff --git a/packages/svelte/package.json b/packages/svelte/package.json
index 22bc8cc8fac6..c781eda8c8d0 100644
--- a/packages/svelte/package.json
+++ b/packages/svelte/package.json
@@ -2,7 +2,7 @@
   "name": "svelte",
   "description": "Cybernetically enhanced web apps",
   "license": "MIT",
-  "version": "5.36.17",
+  "version": "5.37.0",
   "type": "module",
   "types": "./types/index.d.ts",
   "engines": {
diff --git a/packages/svelte/src/version.js b/packages/svelte/src/version.js
index d2992a3dcd8c..e83ba6fb3018 100644
--- a/packages/svelte/src/version.js
+++ b/packages/svelte/src/version.js
@@ -4,5 +4,5 @@
  * The current version, as set in package.json.
  * @type {string}
  */
-export const VERSION = '5.36.17';
+export const VERSION = '5.37.0';
 export const PUBLIC_VERSION = '5';

From 1773df94845bc53d55a1c9e9eb033d08056c845a Mon Sep 17 00:00:00 2001
From: fkobi <fkobi@pm.me>
Date: Sun, 27 Jul 2025 14:17:50 +0000
Subject: [PATCH 7/9] docs: use sh instead of bash in source blocks (#16506)

* use sh instead of bash in source blocks

no bash-specific functionality is used

* regenerate

---------

Co-authored-by: Rich Harris <rich.harris@vercel.com>
---
 CONTRIBUTING.md                                               | 4 ++--
 documentation/docs/01-introduction/02-getting-started.md      | 2 +-
 documentation/docs/07-misc/02-testing.md                      | 4 ++--
 .../docs/98-reference/.generated/compile-warnings.md          | 2 +-
 packages/svelte/README.md                                     | 2 +-
 packages/svelte/messages/compile-warnings/template.md         | 2 +-
 6 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index c2d3e45049c1..0653b08b7640 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -101,13 +101,13 @@ Test samples are kept in `/test/xxx/samples` folder.
 1. To run test, run `pnpm test`.
 1. To run a particular test suite, use `pnpm test <suite-name>`, for example:
 
-   ```bash
+   ```sh
    pnpm test validator
    ```
 
 1. To filter tests _within_ a test suite, use `pnpm test <suite-name> -t <test-name>`, for example:
 
-   ```bash
+   ```sh
    pnpm test validator -t a11y-alt-text
    ```
 
diff --git a/documentation/docs/01-introduction/02-getting-started.md b/documentation/docs/01-introduction/02-getting-started.md
index c7351729ff17..e97a46ad34a8 100644
--- a/documentation/docs/01-introduction/02-getting-started.md
+++ b/documentation/docs/01-introduction/02-getting-started.md
@@ -4,7 +4,7 @@ title: Getting started
 
 We recommend using [SvelteKit](../kit), which lets you [build almost anything](../kit/project-types). It's the official application framework from the Svelte team and powered by [Vite](https://vite.dev/). Create a new project with:
 
-```bash
+```sh
 npx sv create myapp
 cd myapp
 npm install
diff --git a/documentation/docs/07-misc/02-testing.md b/documentation/docs/07-misc/02-testing.md
index db99b7077022..bcec4db0a39b 100644
--- a/documentation/docs/07-misc/02-testing.md
+++ b/documentation/docs/07-misc/02-testing.md
@@ -10,7 +10,7 @@ Unit tests allow you to test small isolated parts of your code. Integration test
 
 To setup Vitest manually, first install it:
 
-```bash
+```sh
 npm install -D vitest
 ```
 
@@ -166,7 +166,7 @@ It is possible to test your components in isolation using Vitest.
 
 To get started, install jsdom (a library that shims DOM APIs):
 
-```bash
+```sh
 npm install -D jsdom
 ```
 
diff --git a/documentation/docs/98-reference/.generated/compile-warnings.md b/documentation/docs/98-reference/.generated/compile-warnings.md
index 2af9021a6a7e..01003f30c57a 100644
--- a/documentation/docs/98-reference/.generated/compile-warnings.md
+++ b/documentation/docs/98-reference/.generated/compile-warnings.md
@@ -683,7 +683,7 @@ Some templating languages (including Svelte) will 'fix' HTML by turning `<span /
 
 To automate this, run the dedicated migration:
 
-```bash
+```sh
 npx sv migrate self-closing-tags
 ```
 
diff --git a/packages/svelte/README.md b/packages/svelte/README.md
index c37617da30eb..03e4db5db0d4 100644
--- a/packages/svelte/README.md
+++ b/packages/svelte/README.md
@@ -19,7 +19,7 @@ You can play around with Svelte in the [tutorial](https://svelte.dev/tutorial),
 
 When you're ready to build a full-fledge application, we recommend using [SvelteKit](https://svelte.dev/docs/kit):
 
-```bash
+```sh
 npx sv create my-app
 cd my-app
 npm install
diff --git a/packages/svelte/messages/compile-warnings/template.md b/packages/svelte/messages/compile-warnings/template.md
index d61a61d95051..8af5aa2b98b0 100644
--- a/packages/svelte/messages/compile-warnings/template.md
+++ b/packages/svelte/messages/compile-warnings/template.md
@@ -71,7 +71,7 @@ Some templating languages (including Svelte) will 'fix' HTML by turning `<span /
 
 To automate this, run the dedicated migration:
 
-```bash
+```sh
 npx sv migrate self-closing-tags
 ```
 

From 99452053af5d3280caa9773ac45f9c7cc6b9ad5d Mon Sep 17 00:00:00 2001
From: Paolo Ricciuti <ricciutipaolo@gmail.com>
Date: Sun, 27 Jul 2025 19:50:22 +0200
Subject: [PATCH 8/9] fix: `append_styles` in an effect to make them available
 on mount (#16509)

Co-authored-by: Rich Harris <rich.harris@vercel.com>
---
 .changeset/shaggy-comics-fail.md              |  5 +++++
 .changeset/wise-hairs-pay.md                  |  5 +++++
 .../src/compiler/phases/2-analyze/index.js    | 16 +++++++-------
 .../3-transform/client/transform-client.js    |  5 +++--
 .../svelte/src/internal/client/dom/css.js     |  4 ++--
 .../host-rune-access-injected-css/_config.js  | 21 +++++++++++++++++++
 .../host-rune-access-injected-css/main.svelte | 16 ++++++++++++++
 .../Thing.svelte                              |  9 ++++++++
 .../custom-element-injected-styles/_config.js | 15 +++++++++++++
 .../main.svelte                               |  5 +++++
 10 files changed, 90 insertions(+), 11 deletions(-)
 create mode 100644 .changeset/shaggy-comics-fail.md
 create mode 100644 .changeset/wise-hairs-pay.md
 create mode 100644 packages/svelte/tests/runtime-browser/custom-elements-samples/host-rune-access-injected-css/_config.js
 create mode 100644 packages/svelte/tests/runtime-browser/custom-elements-samples/host-rune-access-injected-css/main.svelte
 create mode 100644 packages/svelte/tests/runtime-runes/samples/custom-element-injected-styles/Thing.svelte
 create mode 100644 packages/svelte/tests/runtime-runes/samples/custom-element-injected-styles/_config.js
 create mode 100644 packages/svelte/tests/runtime-runes/samples/custom-element-injected-styles/main.svelte

diff --git a/.changeset/shaggy-comics-fail.md b/.changeset/shaggy-comics-fail.md
new file mode 100644
index 000000000000..981a25c978d6
--- /dev/null
+++ b/.changeset/shaggy-comics-fail.md
@@ -0,0 +1,5 @@
+---
+'svelte': patch
+---
+
+fix: `append_styles` in an effect to make them available on mount
diff --git a/.changeset/wise-hairs-pay.md b/.changeset/wise-hairs-pay.md
new file mode 100644
index 000000000000..7d96c1daab15
--- /dev/null
+++ b/.changeset/wise-hairs-pay.md
@@ -0,0 +1,5 @@
+---
+'svelte': patch
+---
+
+fix: always inject styles when compiling as a custom element
diff --git a/packages/svelte/src/compiler/phases/2-analyze/index.js b/packages/svelte/src/compiler/phases/2-analyze/index.js
index d407b4455639..cd44fd998aed 100644
--- a/packages/svelte/src/compiler/phases/2-analyze/index.js
+++ b/packages/svelte/src/compiler/phases/2-analyze/index.js
@@ -451,6 +451,8 @@ export function analyze_component(root, source, options) {
 		}
 	}
 
+	const is_custom_element = !!options.customElementOptions || options.customElement;
+
 	// TODO remove all the ?? stuff, we don't need it now that we're validating the config
 	/** @type {ComponentAnalysis} */
 	const analysis = {
@@ -500,13 +502,13 @@ export function analyze_component(root, source, options) {
 		needs_props: false,
 		event_directive_node: null,
 		uses_event_attributes: false,
-		custom_element: options.customElementOptions ?? options.customElement,
-		inject_styles: options.css === 'injected' || options.customElement,
-		accessors: options.customElement
-			? true
-			: (runes ? false : !!options.accessors) ||
-				// because $set method needs accessors
-				options.compatibility?.componentApi === 4,
+		custom_element: is_custom_element,
+		inject_styles: options.css === 'injected' || is_custom_element,
+		accessors:
+			is_custom_element ||
+			(runes ? false : !!options.accessors) ||
+			// because $set method needs accessors
+			options.compatibility?.componentApi === 4,
 		reactive_statements: new Map(),
 		binding_groups: new Map(),
 		slot_names: new Map(),
diff --git a/packages/svelte/src/compiler/phases/3-transform/client/transform-client.js b/packages/svelte/src/compiler/phases/3-transform/client/transform-client.js
index 124438a9dab0..a56aca9c5f0b 100644
--- a/packages/svelte/src/compiler/phases/3-transform/client/transform-client.js
+++ b/packages/svelte/src/compiler/phases/3-transform/client/transform-client.js
@@ -621,8 +621,9 @@ export function client_component(analysis, options) {
 		);
 	}
 
-	if (analysis.custom_element) {
-		const ce = analysis.custom_element;
+	const ce = options.customElementOptions ?? options.customElement;
+
+	if (ce) {
 		const ce_props = typeof ce === 'boolean' ? {} : ce.props || {};
 
 		/** @type {ESTree.Property[]} */
diff --git a/packages/svelte/src/internal/client/dom/css.js b/packages/svelte/src/internal/client/dom/css.js
index 52be36aa1f46..8e6faa0e32dc 100644
--- a/packages/svelte/src/internal/client/dom/css.js
+++ b/packages/svelte/src/internal/client/dom/css.js
@@ -1,6 +1,6 @@
 import { DEV } from 'esm-env';
-import { queue_micro_task } from './task.js';
 import { register_style } from '../dev/css.js';
+import { effect } from '../reactivity/effects.js';
 
 /**
  * @param {Node} anchor
@@ -8,7 +8,7 @@ import { register_style } from '../dev/css.js';
  */
 export function append_styles(anchor, css) {
 	// Use `queue_micro_task` to ensure `anchor` is in the DOM, otherwise getRootNode() will yield wrong results
-	queue_micro_task(() => {
+	effect(() => {
 		var root = anchor.getRootNode();
 
 		var target = /** @type {ShadowRoot} */ (root).host
diff --git a/packages/svelte/tests/runtime-browser/custom-elements-samples/host-rune-access-injected-css/_config.js b/packages/svelte/tests/runtime-browser/custom-elements-samples/host-rune-access-injected-css/_config.js
new file mode 100644
index 000000000000..99a223492b8b
--- /dev/null
+++ b/packages/svelte/tests/runtime-browser/custom-elements-samples/host-rune-access-injected-css/_config.js
@@ -0,0 +1,21 @@
+import { test } from '../../assert';
+const tick = () => Promise.resolve();
+
+export default test({
+	async test({ assert, target }) {
+		target.innerHTML = '<custom-element></custom-element>';
+		/** @type {any} */
+		const el = target.querySelector('custom-element');
+
+		/** @type {string} */
+		let html = '';
+		const handle_evt = (e) => (html = e.detail);
+		el.addEventListener('html', handle_evt);
+
+		await tick();
+		await tick();
+		await tick();
+
+		assert.ok(html.includes('<style'));
+	}
+});
diff --git a/packages/svelte/tests/runtime-browser/custom-elements-samples/host-rune-access-injected-css/main.svelte b/packages/svelte/tests/runtime-browser/custom-elements-samples/host-rune-access-injected-css/main.svelte
new file mode 100644
index 000000000000..ad8027f4d268
--- /dev/null
+++ b/packages/svelte/tests/runtime-browser/custom-elements-samples/host-rune-access-injected-css/main.svelte
@@ -0,0 +1,16 @@
+<svelte:options css="injected" customElement="custom-element"/>
+
+<script lang="ts">
+  $effect(() => {
+    $host().dispatchEvent(new CustomEvent("html", { detail: $host().shadowRoot?.innerHTML }));
+  })
+</script>
+
+<button class="btn">btn</button>
+
+<style >
+  .btn {
+    width: 123px;
+    height: 123px;
+  }
+</style>
\ No newline at end of file
diff --git a/packages/svelte/tests/runtime-runes/samples/custom-element-injected-styles/Thing.svelte b/packages/svelte/tests/runtime-runes/samples/custom-element-injected-styles/Thing.svelte
new file mode 100644
index 000000000000..0a2b139274d6
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/custom-element-injected-styles/Thing.svelte
@@ -0,0 +1,9 @@
+<svelte:options customElement={{ tag: 'my-thing' }} />
+
+<h1>hello</h1>
+
+<style>
+	h1 {
+		color: red;
+	}
+</style>
diff --git a/packages/svelte/tests/runtime-runes/samples/custom-element-injected-styles/_config.js b/packages/svelte/tests/runtime-runes/samples/custom-element-injected-styles/_config.js
new file mode 100644
index 000000000000..74597504bd92
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/custom-element-injected-styles/_config.js
@@ -0,0 +1,15 @@
+import { tick } from 'svelte';
+import { test } from '../../test';
+
+export default test({
+	mode: ['client'],
+	async test({ assert, target }) {
+		const thing = /** @type HTMLElement & { object: { test: true }; } */ (
+			target.querySelector('my-thing')
+		);
+
+		await tick();
+
+		assert.include(thing.shadowRoot?.innerHTML, 'red');
+	}
+});
diff --git a/packages/svelte/tests/runtime-runes/samples/custom-element-injected-styles/main.svelte b/packages/svelte/tests/runtime-runes/samples/custom-element-injected-styles/main.svelte
new file mode 100644
index 000000000000..ba5b788da9b3
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/custom-element-injected-styles/main.svelte
@@ -0,0 +1,5 @@
+<script>
+	import './Thing.svelte';
+</script>
+
+<my-thing></my-thing>

From 51771447c6cf941da7a07733435a5b18a91ddd28 Mon Sep 17 00:00:00 2001
From: Rich Harris <rich.harris@vercel.com>
Date: Sun, 27 Jul 2025 16:59:29 -0400
Subject: [PATCH 9/9] chore: remove `parser.template_untrimmed` (#16511)

---
 .changeset/shiny-berries-call.md                          | 5 +++++
 packages/svelte/src/compiler/phases/1-parse/index.js      | 7 -------
 .../svelte/src/compiler/phases/1-parse/state/element.js   | 8 --------
 3 files changed, 5 insertions(+), 15 deletions(-)
 create mode 100644 .changeset/shiny-berries-call.md

diff --git a/.changeset/shiny-berries-call.md b/.changeset/shiny-berries-call.md
new file mode 100644
index 000000000000..adc62b3cd017
--- /dev/null
+++ b/.changeset/shiny-berries-call.md
@@ -0,0 +1,5 @@
+---
+'svelte': patch
+---
+
+chore: remove `parser.template_untrimmed`
diff --git a/packages/svelte/src/compiler/phases/1-parse/index.js b/packages/svelte/src/compiler/phases/1-parse/index.js
index 77cc2bf3fa43..f5e0693b311f 100644
--- a/packages/svelte/src/compiler/phases/1-parse/index.js
+++ b/packages/svelte/src/compiler/phases/1-parse/index.js
@@ -23,12 +23,6 @@ export class Parser {
 	 */
 	template;
 
-	/**
-	 * @readonly
-	 * @type {string}
-	 */
-	template_untrimmed;
-
 	/**
 	 * Whether or not we're in loose parsing mode, in which
 	 * case we try to continue parsing as much as possible
@@ -67,7 +61,6 @@ export class Parser {
 		}
 
 		this.loose = loose;
-		this.template_untrimmed = template;
 		this.template = template.trimEnd();
 
 		let match_lang;
diff --git a/packages/svelte/src/compiler/phases/1-parse/state/element.js b/packages/svelte/src/compiler/phases/1-parse/state/element.js
index 87332f647d86..ed1b047d5556 100644
--- a/packages/svelte/src/compiler/phases/1-parse/state/element.js
+++ b/packages/svelte/src/compiler/phases/1-parse/state/element.js
@@ -370,14 +370,6 @@ export default function element(parser) {
 				// ... or we're followed by whitespace, for example near the end of the template,
 				// which we want to take in so that language tools has more room to work with
 				parser.allow_whitespace();
-				if (parser.index === parser.template.length) {
-					while (
-						parser.index < parser.template_untrimmed.length &&
-						regex_whitespace.test(parser.template_untrimmed[parser.index])
-					) {
-						parser.index++;
-					}
-				}
 			}
 		}
 	}

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<title>pFad - Phonifier reborn</title>
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<h1>Pfad - The Proxy pFad of &#169; 2024 Garber Painting. All rights reserved.</h1>


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<p>Note: This service is not intended for secure transactions such as banking, social media, email, or purchasing. Use at your own risk. We assume no liability whatsoever for broken pages.</p>
<br>
<p>Alternative Proxies:</p><p><a href="http://clevelandohioweatherforecast.com/php-proxy/index.php?q=https://github.com/sveltejs/svelte/compare/sveltejs:8ad02e4...sveltejs:5177144.patch" target="_blank">Alternative Proxy</a></p><p><a href="http://clevelandohioweatherforecast.com/pFad/index.php?u=https://github.com/sveltejs/svelte/compare/sveltejs:8ad02e4...sveltejs:5177144.patch" target="_blank">pFad Proxy</a></p><p><a href="http://clevelandohioweatherforecast.com/pFad/v3index.php?u=https://github.com/sveltejs/svelte/compare/sveltejs:8ad02e4...sveltejs:5177144.patch" target="_blank">pFad v3 Proxy</a></p><p><a href="http://clevelandohioweatherforecast.com/pFad/v4index.php?u=https://github.com/sveltejs/svelte/compare/sveltejs:8ad02e4...sveltejs:5177144.patch" target="_blank">pFad v4 Proxy</a></p></body>
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