From d0dcc0b79534f377349e7f6aa4a97c7b55f51864 Mon Sep 17 00:00:00 2001
From: ComputerGuy <63362464+Ocean-OS@users.noreply.github.com>
Date: Fri, 18 Apr 2025 08:19:37 -0700
Subject: [PATCH 1/6] fix: improve partial evaluation (#15781)

* init

* remove console log

* Update packages/svelte/src/compiler/phases/scope.js

* fix each indices

* dedupe

* Update packages/svelte/src/compiler/phases/scope.js

* always break

* fix formatting

* Apply suggestions from code review

* compactify

* compactify

* reuse values

* add more globals, template literals, try functions and (some) member expressions

* remove console logs

* remove function handling, tweak failing test

* changeset

* try putting static stuff in the template

* nevermind

* unused

* simplify

* Update packages/svelte/src/compiler/phases/3-transform/client/visitors/shared/utils.js

* YAGNI

* simplify and fix (should use cooked, not raw)

* unused

* changeset

---------

Co-authored-by: Rich Harris <hello@rich-harris.dev>
Co-authored-by: Rich Harris <rich.harris@vercel.com>
---
 .changeset/serious-adults-sit.md              |   5 +
 .../client/visitors/shared/utils.js           |  10 +-
 packages/svelte/src/compiler/phases/scope.js  | 210 ++++++++++++++++--
 .../samples/each-index-non-null/_config.js    |   3 +
 .../_expected/client/index.svelte.js          |  19 ++
 .../_expected/server/index.svelte.js          |  13 ++
 .../samples/each-index-non-null/index.svelte  |   3 +
 .../purity/_expected/client/index.svelte.js   |   2 +-
 .../purity/_expected/server/index.svelte.js   |   2 +-
 9 files changed, 243 insertions(+), 24 deletions(-)
 create mode 100644 .changeset/serious-adults-sit.md
 create mode 100644 packages/svelte/tests/snapshot/samples/each-index-non-null/_config.js
 create mode 100644 packages/svelte/tests/snapshot/samples/each-index-non-null/_expected/client/index.svelte.js
 create mode 100644 packages/svelte/tests/snapshot/samples/each-index-non-null/_expected/server/index.svelte.js
 create mode 100644 packages/svelte/tests/snapshot/samples/each-index-non-null/index.svelte

diff --git a/.changeset/serious-adults-sit.md b/.changeset/serious-adults-sit.md
new file mode 100644
index 0000000000..8c98a7c366
--- /dev/null
+++ b/.changeset/serious-adults-sit.md
@@ -0,0 +1,5 @@
+---
+'svelte': minor
+---
+
+feat: partially evaluate more expressions
diff --git a/packages/svelte/src/compiler/phases/3-transform/client/visitors/shared/utils.js b/packages/svelte/src/compiler/phases/3-transform/client/visitors/shared/utils.js
index 380cf6cd02..bc79b76043 100644
--- a/packages/svelte/src/compiler/phases/3-transform/client/visitors/shared/utils.js
+++ b/packages/svelte/src/compiler/phases/3-transform/client/visitors/shared/utils.js
@@ -69,11 +69,17 @@ export function build_template_chunk(
 				node.metadata.expression
 			);
 
-			has_state ||= node.metadata.expression.has_state;
+			const evaluated = state.scope.evaluate(value);
+
+			has_state ||= node.metadata.expression.has_state && !evaluated.is_known;
 
 			if (values.length === 1) {
 				// If we have a single expression, then pass that in directly to possibly avoid doing
 				// extra work in the template_effect (instead we do the work in set_text).
+				if (evaluated.is_known) {
+					value = b.literal(evaluated.value);
+				}
+
 				return { value, has_state };
 			}
 
@@ -89,8 +95,6 @@ export function build_template_chunk(
 				}
 			}
 
-			const evaluated = state.scope.evaluate(value);
-
 			if (evaluated.is_known) {
 				quasi.value.cooked += evaluated.value + '';
 			} else {
diff --git a/packages/svelte/src/compiler/phases/scope.js b/packages/svelte/src/compiler/phases/scope.js
index 570d5e22d9..8297f174d3 100644
--- a/packages/svelte/src/compiler/phases/scope.js
+++ b/packages/svelte/src/compiler/phases/scope.js
@@ -1,4 +1,4 @@
-/** @import { ArrowFunctionExpression, BinaryOperator, ClassDeclaration, Expression, FunctionDeclaration, FunctionExpression, Identifier, ImportDeclaration, MemberExpression, LogicalOperator, Node, Pattern, UnaryOperator, VariableDeclarator } from 'estree' */
+/** @import { ArrowFunctionExpression, BinaryOperator, ClassDeclaration, Expression, FunctionDeclaration, FunctionExpression, Identifier, ImportDeclaration, MemberExpression, LogicalOperator, Node, Pattern, UnaryOperator, VariableDeclarator, Super } from 'estree' */
 /** @import { Context, Visitor } from 'zimmerframe' */
 /** @import { AST, BindingKind, DeclarationKind } from '#compiler' */
 import is_reference from 'is-reference';
@@ -18,8 +18,71 @@ import { validate_identifier_name } from './2-analyze/visitors/shared/utils.js';
 
 const UNKNOWN = Symbol('unknown');
 /** Includes `BigInt` */
-const NUMBER = Symbol('number');
-const STRING = Symbol('string');
+export const NUMBER = Symbol('number');
+export const STRING = Symbol('string');
+
+/** @type {Record<string, [type: NUMBER | STRING | UNKNOWN, fn?: Function]>} */
+const globals = {
+	BigInt: [NUMBER, BigInt],
+	'Math.min': [NUMBER, Math.min],
+	'Math.max': [NUMBER, Math.max],
+	'Math.random': [NUMBER],
+	'Math.floor': [NUMBER, Math.floor],
+	// @ts-expect-error
+	'Math.f16round': [NUMBER, Math.f16round],
+	'Math.round': [NUMBER, Math.round],
+	'Math.abs': [NUMBER, Math.abs],
+	'Math.acos': [NUMBER, Math.acos],
+	'Math.asin': [NUMBER, Math.asin],
+	'Math.atan': [NUMBER, Math.atan],
+	'Math.atan2': [NUMBER, Math.atan2],
+	'Math.ceil': [NUMBER, Math.ceil],
+	'Math.cos': [NUMBER, Math.cos],
+	'Math.sin': [NUMBER, Math.sin],
+	'Math.tan': [NUMBER, Math.tan],
+	'Math.exp': [NUMBER, Math.exp],
+	'Math.log': [NUMBER, Math.log],
+	'Math.pow': [NUMBER, Math.pow],
+	'Math.sqrt': [NUMBER, Math.sqrt],
+	'Math.clz32': [NUMBER, Math.clz32],
+	'Math.imul': [NUMBER, Math.imul],
+	'Math.sign': [NUMBER, Math.sign],
+	'Math.log10': [NUMBER, Math.log10],
+	'Math.log2': [NUMBER, Math.log2],
+	'Math.log1p': [NUMBER, Math.log1p],
+	'Math.expm1': [NUMBER, Math.expm1],
+	'Math.cosh': [NUMBER, Math.cosh],
+	'Math.sinh': [NUMBER, Math.sinh],
+	'Math.tanh': [NUMBER, Math.tanh],
+	'Math.acosh': [NUMBER, Math.acosh],
+	'Math.asinh': [NUMBER, Math.asinh],
+	'Math.atanh': [NUMBER, Math.atanh],
+	'Math.trunc': [NUMBER, Math.trunc],
+	'Math.fround': [NUMBER, Math.fround],
+	'Math.cbrt': [NUMBER, Math.cbrt],
+	Number: [NUMBER, Number],
+	'Number.isInteger': [NUMBER, Number.isInteger],
+	'Number.isFinite': [NUMBER, Number.isFinite],
+	'Number.isNaN': [NUMBER, Number.isNaN],
+	'Number.isSafeInteger': [NUMBER, Number.isSafeInteger],
+	'Number.parseFloat': [NUMBER, Number.parseFloat],
+	'Number.parseInt': [NUMBER, Number.parseInt],
+	String: [STRING, String],
+	'String.fromCharCode': [STRING, String.fromCharCode],
+	'String.fromCodePoint': [STRING, String.fromCodePoint]
+};
+
+/** @type {Record<string, any>} */
+const global_constants = {
+	'Math.PI': Math.PI,
+	'Math.E': Math.E,
+	'Math.LN10': Math.LN10,
+	'Math.LN2': Math.LN2,
+	'Math.LOG10E': Math.LOG10E,
+	'Math.LOG2E': Math.LOG2E,
+	'Math.SQRT2': Math.SQRT2,
+	'Math.SQRT1_2': Math.SQRT1_2
+};
 
 export class Binding {
 	/** @type {Scope} */
@@ -107,7 +170,7 @@ export class Binding {
 
 class Evaluation {
 	/** @type {Set<any>} */
-	values = new Set();
+	values;
 
 	/**
 	 * True if there is exactly one possible value
@@ -147,8 +210,11 @@ class Evaluation {
 	 *
 	 * @param {Scope} scope
 	 * @param {Expression} expression
+	 * @param {Set<any>} values
 	 */
-	constructor(scope, expression) {
+	constructor(scope, expression, values) {
+		this.values = values;
+
 		switch (expression.type) {
 			case 'Literal': {
 				this.values.add(expression.value);
@@ -172,15 +238,18 @@ class Evaluation {
 						binding.kind === 'rest_prop' ||
 						binding.kind === 'bindable_prop';
 
-					if (!binding.updated && binding.initial !== null && !is_prop) {
-						const evaluation = binding.scope.evaluate(/** @type {Expression} */ (binding.initial));
-						for (const value of evaluation.values) {
-							this.values.add(value);
-						}
+					if (binding.initial?.type === 'EachBlock' && binding.initial.index === expression.name) {
+						this.values.add(NUMBER);
 						break;
 					}
 
-					// TODO each index is always defined
+					if (!binding.updated && binding.initial !== null && !is_prop) {
+						binding.scope.evaluate(/** @type {Expression} */ (binding.initial), this.values);
+						break;
+					}
+				} else if (expression.name === 'undefined') {
+					this.values.add(undefined);
+					break;
 				}
 
 				// TODO glean what we can from reassignments
@@ -336,6 +405,101 @@ class Evaluation {
 				break;
 			}
 
+			case 'CallExpression': {
+				const keypath = get_global_keypath(expression.callee, scope);
+
+				if (keypath) {
+					if (is_rune(keypath)) {
+						const arg = /** @type {Expression | undefined} */ (expression.arguments[0]);
+
+						switch (keypath) {
+							case '$state':
+							case '$state.raw':
+							case '$derived':
+								if (arg) {
+									scope.evaluate(arg, this.values);
+								} else {
+									this.values.add(undefined);
+								}
+								break;
+
+							case '$props.id':
+								this.values.add(STRING);
+								break;
+
+							case '$effect.tracking':
+								this.values.add(false);
+								this.values.add(true);
+								break;
+
+							case '$derived.by':
+								if (arg?.type === 'ArrowFunctionExpression' && arg.body.type !== 'BlockStatement') {
+									scope.evaluate(arg.body, this.values);
+									break;
+								}
+
+								this.values.add(UNKNOWN);
+								break;
+
+							default: {
+								this.values.add(UNKNOWN);
+							}
+						}
+
+						break;
+					}
+
+					if (
+						Object.hasOwn(globals, keypath) &&
+						expression.arguments.every((arg) => arg.type !== 'SpreadElement')
+					) {
+						const [type, fn] = globals[keypath];
+						const values = expression.arguments.map((arg) => scope.evaluate(arg));
+
+						if (fn && values.every((e) => e.is_known)) {
+							this.values.add(fn(...values.map((e) => e.value)));
+						} else {
+							this.values.add(type);
+						}
+
+						break;
+					}
+				}
+
+				this.values.add(UNKNOWN);
+				break;
+			}
+
+			case 'TemplateLiteral': {
+				let result = expression.quasis[0].value.cooked;
+
+				for (let i = 0; i < expression.expressions.length; i += 1) {
+					const e = scope.evaluate(expression.expressions[i]);
+
+					if (e.is_known) {
+						result += e.value + expression.quasis[i + 1].value.cooked;
+					} else {
+						this.values.add(STRING);
+						break;
+					}
+				}
+
+				this.values.add(result);
+				break;
+			}
+
+			case 'MemberExpression': {
+				const keypath = get_global_keypath(expression, scope);
+
+				if (keypath && Object.hasOwn(global_constants, keypath)) {
+					this.values.add(global_constants[keypath]);
+					break;
+				}
+
+				this.values.add(UNKNOWN);
+				break;
+			}
+
 			default: {
 				this.values.add(UNKNOWN);
 			}
@@ -548,10 +712,10 @@ export class Scope {
 	 * Only call this once scope has been fully generated in a first pass,
 	 * else this evaluates on incomplete data and may yield wrong results.
 	 * @param {Expression} expression
-	 * @param {Set<any>} values
+	 * @param {Set<any>} [values]
 	 */
 	evaluate(expression, values = new Set()) {
-		return new Evaluation(this, expression);
+		return new Evaluation(this, expression, values);
 	}
 }
 
@@ -1115,7 +1279,19 @@ export function get_rune(node, scope) {
 	if (!node) return null;
 	if (node.type !== 'CallExpression') return null;
 
-	let n = node.callee;
+	const keypath = get_global_keypath(node.callee, scope);
+
+	if (!keypath || !is_rune(keypath)) return null;
+	return keypath;
+}
+
+/**
+ * Returns the name of the rune if the given expression is a `CallExpression` using a rune.
+ * @param {Expression | Super} node
+ * @param {Scope} scope
+ */
+function get_global_keypath(node, scope) {
+	let n = node;
 
 	let joined = '';
 
@@ -1133,12 +1309,8 @@ export function get_rune(node, scope) {
 
 	if (n.type !== 'Identifier') return null;
 
-	joined = n.name + joined;
-
-	if (!is_rune(joined)) return null;
-
 	const binding = scope.get(n.name);
 	if (binding !== null) return null; // rune name, but references a variable or store
 
-	return joined;
+	return n.name + joined;
 }
diff --git a/packages/svelte/tests/snapshot/samples/each-index-non-null/_config.js b/packages/svelte/tests/snapshot/samples/each-index-non-null/_config.js
new file mode 100644
index 0000000000..f47bee71df
--- /dev/null
+++ b/packages/svelte/tests/snapshot/samples/each-index-non-null/_config.js
@@ -0,0 +1,3 @@
+import { test } from '../../test';
+
+export default test({});
diff --git a/packages/svelte/tests/snapshot/samples/each-index-non-null/_expected/client/index.svelte.js b/packages/svelte/tests/snapshot/samples/each-index-non-null/_expected/client/index.svelte.js
new file mode 100644
index 0000000000..3d46a679b8
--- /dev/null
+++ b/packages/svelte/tests/snapshot/samples/each-index-non-null/_expected/client/index.svelte.js
@@ -0,0 +1,19 @@
+import 'svelte/internal/disclose-version';
+import 'svelte/internal/flags/legacy';
+import * as $ from 'svelte/internal/client';
+
+var root_1 = $.template(`<p></p>`);
+
+export default function Each_index_non_null($$anchor) {
+	var fragment = $.comment();
+	var node = $.first_child(fragment);
+
+	$.each(node, 0, () => Array(10), $.index, ($$anchor, $$item, i) => {
+		var p = root_1();
+
+		p.textContent = `index: ${i}`;
+		$.append($$anchor, p);
+	});
+
+	$.append($$anchor, fragment);
+}
\ No newline at end of file
diff --git a/packages/svelte/tests/snapshot/samples/each-index-non-null/_expected/server/index.svelte.js b/packages/svelte/tests/snapshot/samples/each-index-non-null/_expected/server/index.svelte.js
new file mode 100644
index 0000000000..3431e36833
--- /dev/null
+++ b/packages/svelte/tests/snapshot/samples/each-index-non-null/_expected/server/index.svelte.js
@@ -0,0 +1,13 @@
+import * as $ from 'svelte/internal/server';
+
+export default function Each_index_non_null($$payload) {
+	const each_array = $.ensure_array_like(Array(10));
+
+	$$payload.out += `<!--[-->`;
+
+	for (let i = 0, $$length = each_array.length; i < $$length; i++) {
+		$$payload.out += `<p>index: ${$.escape(i)}</p>`;
+	}
+
+	$$payload.out += `<!--]-->`;
+}
\ No newline at end of file
diff --git a/packages/svelte/tests/snapshot/samples/each-index-non-null/index.svelte b/packages/svelte/tests/snapshot/samples/each-index-non-null/index.svelte
new file mode 100644
index 0000000000..03bfc9e372
--- /dev/null
+++ b/packages/svelte/tests/snapshot/samples/each-index-non-null/index.svelte
@@ -0,0 +1,3 @@
+{#each Array(10), i}
+	<p>index: {i}</p>
+{/each}
diff --git a/packages/svelte/tests/snapshot/samples/purity/_expected/client/index.svelte.js b/packages/svelte/tests/snapshot/samples/purity/_expected/client/index.svelte.js
index 940ed8f9e8..5bc9766acf 100644
--- a/packages/svelte/tests/snapshot/samples/purity/_expected/client/index.svelte.js
+++ b/packages/svelte/tests/snapshot/samples/purity/_expected/client/index.svelte.js
@@ -8,7 +8,7 @@ export default function Purity($$anchor) {
 	var fragment = root();
 	var p = $.first_child(fragment);
 
-	p.textContent = Math.max(0, Math.min(0, 100));
+	p.textContent = 0;
 
 	var p_1 = $.sibling(p, 2);
 
diff --git a/packages/svelte/tests/snapshot/samples/purity/_expected/server/index.svelte.js b/packages/svelte/tests/snapshot/samples/purity/_expected/server/index.svelte.js
index 588332407a..9457378c0d 100644
--- a/packages/svelte/tests/snapshot/samples/purity/_expected/server/index.svelte.js
+++ b/packages/svelte/tests/snapshot/samples/purity/_expected/server/index.svelte.js
@@ -1,7 +1,7 @@
 import * as $ from 'svelte/internal/server';
 
 export default function Purity($$payload) {
-	$$payload.out += `<p>${$.escape(Math.max(0, Math.min(0, 100)))}</p> <p>${$.escape(location.href)}</p> `;
+	$$payload.out += `<p>0</p> <p>${$.escape(location.href)}</p> `;
 	Child($$payload, { prop: encodeURIComponent('hello') });
 	$$payload.out += `<!---->`;
 }
\ No newline at end of file

From 6fe5977b3d0bfd86d7b8e47f9e5374ffa31fba56 Mon Sep 17 00:00:00 2001
From: "github-actions[bot]"
 <41898282+github-actions[bot]@users.noreply.github.com>
Date: Fri, 18 Apr 2025 11:27:19 -0400
Subject: [PATCH 2/6] Version Packages (#15798)

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>
---
 .changeset/serious-adults-sit.md | 5 -----
 packages/svelte/CHANGELOG.md     | 6 ++++++
 packages/svelte/package.json     | 2 +-
 packages/svelte/src/version.js   | 2 +-
 4 files changed, 8 insertions(+), 7 deletions(-)
 delete mode 100644 .changeset/serious-adults-sit.md

diff --git a/.changeset/serious-adults-sit.md b/.changeset/serious-adults-sit.md
deleted file mode 100644
index 8c98a7c366..0000000000
--- a/.changeset/serious-adults-sit.md
+++ /dev/null
@@ -1,5 +0,0 @@
----
-'svelte': minor
----
-
-feat: partially evaluate more expressions
diff --git a/packages/svelte/CHANGELOG.md b/packages/svelte/CHANGELOG.md
index 709b829fcd..8c01c71099 100644
--- a/packages/svelte/CHANGELOG.md
+++ b/packages/svelte/CHANGELOG.md
@@ -1,5 +1,11 @@
 # svelte
 
+## 5.28.0
+
+### Minor Changes
+
+- feat: partially evaluate more expressions ([#15781](https://github.com/sveltejs/svelte/pull/15781))
+
 ## 5.27.3
 
 ### Patch Changes
diff --git a/packages/svelte/package.json b/packages/svelte/package.json
index efead5604c..784b14ea26 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": "5.27.3",
+  "version": "5.28.0",
   "type": "module",
   "types": "./types/index.d.ts",
   "engines": {
diff --git a/packages/svelte/src/version.js b/packages/svelte/src/version.js
index c64eded9c4..4418204eca 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 = '5.27.3';
+export const VERSION = '5.28.0';
 export const PUBLIC_VERSION = '5';

From d8c6afde944a61c648c6b6f416f5ccafde272d44 Mon Sep 17 00:00:00 2001
From: 7nik <kfiiranet@gmail.com>
Date: Fri, 18 Apr 2025 18:48:27 +0300
Subject: [PATCH 3/6] fix: emit error on wrong placement of the `:global` block
 selector (#15794)

Co-authored-by: 7nik <kifiranet@gmail.com>
---
 .changeset/pretty-beers-care.md                          | 5 +++++
 .../docs/98-reference/.generated/compile-errors.md       | 6 ++++++
 packages/svelte/messages/compile-errors/style.md         | 4 ++++
 packages/svelte/src/compiler/errors.js                   | 9 +++++++++
 .../src/compiler/phases/2-analyze/css/css-analyze.js     | 6 +++++-
 .../samples/css-global-block-in-pseudoclass/_config.js   | 9 +++++++++
 .../samples/css-global-block-in-pseudoclass/main.svelte  | 4 ++++
 7 files changed, 42 insertions(+), 1 deletion(-)
 create mode 100644 .changeset/pretty-beers-care.md
 create mode 100644 packages/svelte/tests/compiler-errors/samples/css-global-block-in-pseudoclass/_config.js
 create mode 100644 packages/svelte/tests/compiler-errors/samples/css-global-block-in-pseudoclass/main.svelte

diff --git a/.changeset/pretty-beers-care.md b/.changeset/pretty-beers-care.md
new file mode 100644
index 0000000000..821bad41c4
--- /dev/null
+++ b/.changeset/pretty-beers-care.md
@@ -0,0 +1,5 @@
+---
+'svelte': patch
+---
+
+fix: emit error on wrong placement of the `:global` block selector
diff --git a/documentation/docs/98-reference/.generated/compile-errors.md b/documentation/docs/98-reference/.generated/compile-errors.md
index 6196a85ade..e8669ead53 100644
--- a/documentation/docs/98-reference/.generated/compile-errors.md
+++ b/documentation/docs/98-reference/.generated/compile-errors.md
@@ -274,6 +274,12 @@ A `:global` selector cannot modify an existing selector
 A `:global` selector can only be modified if it is a descendant of other selectors
 ```
 
+### css_global_block_invalid_placement
+
+```
+A `:global` selector cannot be inside a pseudoclass
+```
+
 ### css_global_invalid_placement
 
 ```
diff --git a/packages/svelte/messages/compile-errors/style.md b/packages/svelte/messages/compile-errors/style.md
index f08a2156a3..272efbccce 100644
--- a/packages/svelte/messages/compile-errors/style.md
+++ b/packages/svelte/messages/compile-errors/style.md
@@ -50,6 +50,10 @@ x y {
 
 > A `:global` selector can only be modified if it is a descendant of other selectors
 
+## css_global_block_invalid_placement
+
+> A `:global` selector cannot be inside a pseudoclass
+
 ## css_global_invalid_placement
 
 > `:global(...)` can be at the start or end of a selector sequence, but not in the middle
diff --git a/packages/svelte/src/compiler/errors.js b/packages/svelte/src/compiler/errors.js
index aa328764e1..c99f597468 100644
--- a/packages/svelte/src/compiler/errors.js
+++ b/packages/svelte/src/compiler/errors.js
@@ -581,6 +581,15 @@ export function css_global_block_invalid_modifier_start(node) {
 	e(node, 'css_global_block_invalid_modifier_start', `A \`:global\` selector can only be modified if it is a descendant of other selectors\nhttps://svelte.dev/e/css_global_block_invalid_modifier_start`);
 }
 
+/**
+ * A `:global` selector cannot be inside a pseudoclass
+ * @param {null | number | NodeLike} node
+ * @returns {never}
+ */
+export function css_global_block_invalid_placement(node) {
+	e(node, 'css_global_block_invalid_placement', `A \`:global\` selector cannot be inside a pseudoclass\nhttps://svelte.dev/e/css_global_block_invalid_placement`);
+}
+
 /**
  * `:global(...)` can be at the start or end of a selector sequence, but not in the middle
  * @param {null | number | NodeLike} node
diff --git a/packages/svelte/src/compiler/phases/2-analyze/css/css-analyze.js b/packages/svelte/src/compiler/phases/2-analyze/css/css-analyze.js
index 2dc3435648..d6052c9c3e 100644
--- a/packages/svelte/src/compiler/phases/2-analyze/css/css-analyze.js
+++ b/packages/svelte/src/compiler/phases/2-analyze/css/css-analyze.js
@@ -68,8 +68,12 @@ const css_visitors = {
 			const global = node.children.find(is_global);
 
 			if (global) {
-				const idx = node.children.indexOf(global);
+				const is_nested = context.path.at(-2)?.type === 'PseudoClassSelector';
+				if (is_nested && !global.selectors[0].args) {
+					e.css_global_block_invalid_placement(global.selectors[0]);
+				}
 
+				const idx = node.children.indexOf(global);
 				if (global.selectors[0].args !== null && idx !== 0 && idx !== node.children.length - 1) {
 					// ensure `:global(...)` is not used in the middle of a selector (but multiple `global(...)` in sequence are ok)
 					for (let i = idx + 1; i < node.children.length; i++) {
diff --git a/packages/svelte/tests/compiler-errors/samples/css-global-block-in-pseudoclass/_config.js b/packages/svelte/tests/compiler-errors/samples/css-global-block-in-pseudoclass/_config.js
new file mode 100644
index 0000000000..c987725d74
--- /dev/null
+++ b/packages/svelte/tests/compiler-errors/samples/css-global-block-in-pseudoclass/_config.js
@@ -0,0 +1,9 @@
+import { test } from '../../test';
+
+export default test({
+	error: {
+		code: 'css_global_block_invalid_placement',
+		message: 'A `:global` selector cannot be inside a pseudoclass',
+		position: [28, 35]
+	}
+});
diff --git a/packages/svelte/tests/compiler-errors/samples/css-global-block-in-pseudoclass/main.svelte b/packages/svelte/tests/compiler-errors/samples/css-global-block-in-pseudoclass/main.svelte
new file mode 100644
index 0000000000..53060df97d
--- /dev/null
+++ b/packages/svelte/tests/compiler-errors/samples/css-global-block-in-pseudoclass/main.svelte
@@ -0,0 +1,4 @@
+<style>
+	/* invalid */
+	:is(:global) { color: red }
+</style>

From 3d808840298dcd7fbb40dfa90700082911e514e7 Mon Sep 17 00:00:00 2001
From: Paolo Ricciuti <ricciutipaolo@gmail.com>
Date: Fri, 18 Apr 2025 17:50:38 +0200
Subject: [PATCH 4/6] fix: `update_version` after `delete` if `source` is
 `undefined` and `prop` in `target` (#15796)

* fix: `update_version` after `delete` if `source` is `undefined` and `prop` in `target`

* chore: remove submodule

* tweak test

---------

Co-authored-by: Rich Harris <rich.harris@vercel.com>
---
 .changeset/great-colts-film.md                      |  5 +++++
 packages/svelte/src/internal/client/proxy.js        |  1 +
 .../samples/delete-proxy-key/_config.js             | 13 +++++++++++++
 .../samples/delete-proxy-key/main.svelte            | 13 +++++++++++++
 4 files changed, 32 insertions(+)
 create mode 100644 .changeset/great-colts-film.md
 create mode 100644 packages/svelte/tests/runtime-runes/samples/delete-proxy-key/_config.js
 create mode 100644 packages/svelte/tests/runtime-runes/samples/delete-proxy-key/main.svelte

diff --git a/.changeset/great-colts-film.md b/.changeset/great-colts-film.md
new file mode 100644
index 0000000000..273509c107
--- /dev/null
+++ b/.changeset/great-colts-film.md
@@ -0,0 +1,5 @@
+---
+'svelte': patch
+---
+
+fix: `update_version` after `delete` if `source` is `undefined` and `prop` in `target`
diff --git a/packages/svelte/src/internal/client/proxy.js b/packages/svelte/src/internal/client/proxy.js
index d690790e3a..fd5706eaf2 100644
--- a/packages/svelte/src/internal/client/proxy.js
+++ b/packages/svelte/src/internal/client/proxy.js
@@ -100,6 +100,7 @@ export function proxy(value) {
 						prop,
 						with_parent(() => source(UNINITIALIZED, stack))
 					);
+					update_version(version);
 				}
 			} else {
 				// When working with arrays, we need to also ensure we update the length when removing
diff --git a/packages/svelte/tests/runtime-runes/samples/delete-proxy-key/_config.js b/packages/svelte/tests/runtime-runes/samples/delete-proxy-key/_config.js
new file mode 100644
index 0000000000..23141a01cd
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/delete-proxy-key/_config.js
@@ -0,0 +1,13 @@
+import { test } from '../../test';
+import { flushSync } from 'svelte';
+
+export default test({
+	html: `<button>delete</button><p>test</p>`,
+
+	async test({ assert, target }) {
+		const btn = target.querySelector('button');
+
+		flushSync(() => btn?.click());
+		assert.htmlEqual(target.innerHTML, '<button>delete</button>');
+	}
+});
diff --git a/packages/svelte/tests/runtime-runes/samples/delete-proxy-key/main.svelte b/packages/svelte/tests/runtime-runes/samples/delete-proxy-key/main.svelte
new file mode 100644
index 0000000000..d3c519c401
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/delete-proxy-key/main.svelte
@@ -0,0 +1,13 @@
+<script>
+	let obj = $state({test: 0})
+
+	let keys = $derived(Object.keys(obj));
+</script>
+
+<button onclick={() => delete obj.test}>
+	delete
+</button>
+
+{#each keys as key}
+	<p>{key}</p>
+{/each}

From b2d5787a09bffefb716d72706460d8b66e96c862 Mon Sep 17 00:00:00 2001
From: zeroberry <98147817+zeroberry@users.noreply.github.com>
Date: Sat, 19 Apr 2025 01:16:25 +0900
Subject: [PATCH 5/6] fix: ensure `<svelte:boundary>` properly removes error
 content in production mode (#15793)

* fix: ensure <svelte:boundary> properly removes error content in production mode

* add changeset
---
 .changeset/eleven-roses-speak.md              |  5 ++
 .../svelte/src/internal/client/runtime.js     | 79 ++++++++-----------
 .../samples/error-boundary-22/Child.svelte    |  3 +
 .../samples/error-boundary-22/_config.js      | 11 +++
 .../samples/error-boundary-22/main.svelte     | 15 ++++
 5 files changed, 69 insertions(+), 44 deletions(-)
 create mode 100644 .changeset/eleven-roses-speak.md
 create mode 100644 packages/svelte/tests/runtime-runes/samples/error-boundary-22/Child.svelte
 create mode 100644 packages/svelte/tests/runtime-runes/samples/error-boundary-22/_config.js
 create mode 100644 packages/svelte/tests/runtime-runes/samples/error-boundary-22/main.svelte

diff --git a/.changeset/eleven-roses-speak.md b/.changeset/eleven-roses-speak.md
new file mode 100644
index 0000000000..0d906f3b5f
--- /dev/null
+++ b/.changeset/eleven-roses-speak.md
@@ -0,0 +1,5 @@
+---
+'svelte': patch
+---
+
+fix: ensure <svelte:boundary> properly removes error content in production mode
diff --git a/packages/svelte/src/internal/client/runtime.js b/packages/svelte/src/internal/client/runtime.js
index 7595aa4a19..fccea3e856 100644
--- a/packages/svelte/src/internal/client/runtime.js
+++ b/packages/svelte/src/internal/client/runtime.js
@@ -291,31 +291,21 @@ export function handle_error(error, effect, previous_effect, component_context)
 		is_throwing_error = true;
 	}
 
-	if (
-		!DEV ||
-		component_context === null ||
-		!(error instanceof Error) ||
-		handled_errors.has(error)
-	) {
-		propagate_error(error, effect);
-		return;
-	}
-
-	handled_errors.add(error);
+	if (DEV && component_context !== null && error instanceof Error && !handled_errors.has(error)) {
+		handled_errors.add(error);
 
-	const component_stack = [];
+		const component_stack = [];
 
-	const effect_name = effect.fn?.name;
+		const effect_name = effect.fn?.name;
 
-	if (effect_name) {
-		component_stack.push(effect_name);
-	}
+		if (effect_name) {
+			component_stack.push(effect_name);
+		}
 
-	/** @type {ComponentContext | null} */
-	let current_context = component_context;
+		/** @type {ComponentContext | null} */
+		let current_context = component_context;
 
-	while (current_context !== null) {
-		if (DEV) {
+		while (current_context !== null) {
 			/** @type {string} */
 			var filename = current_context.function?.[FILENAME];
 
@@ -323,35 +313,36 @@ export function handle_error(error, effect, previous_effect, component_context)
 				const file = filename.split('/').pop();
 				component_stack.push(file);
 			}
+
+			current_context = current_context.p;
 		}
 
-		current_context = current_context.p;
-	}
+		const indent = is_firefox ? '  ' : '\t';
+		define_property(error, 'message', {
+			value:
+				error.message + `\n${component_stack.map((name) => `\n${indent}in ${name}`).join('')}\n`
+		});
+		define_property(error, 'component_stack', {
+			value: component_stack
+		});
 
-	const indent = is_firefox ? '  ' : '\t';
-	define_property(error, 'message', {
-		value: error.message + `\n${component_stack.map((name) => `\n${indent}in ${name}`).join('')}\n`
-	});
-	define_property(error, 'component_stack', {
-		value: component_stack
-	});
-
-	const stack = error.stack;
-
-	// Filter out internal files from callstack
-	if (stack) {
-		const lines = stack.split('\n');
-		const new_lines = [];
-		for (let i = 0; i < lines.length; i++) {
-			const line = lines[i];
-			if (line.includes('svelte/src/internal')) {
-				continue;
+		const stack = error.stack;
+
+		// Filter out internal files from callstack
+		if (stack) {
+			const lines = stack.split('\n');
+			const new_lines = [];
+			for (let i = 0; i < lines.length; i++) {
+				const line = lines[i];
+				if (line.includes('svelte/src/internal')) {
+					continue;
+				}
+				new_lines.push(line);
 			}
-			new_lines.push(line);
+			define_property(error, 'stack', {
+				value: new_lines.join('\n')
+			});
 		}
-		define_property(error, 'stack', {
-			value: new_lines.join('\n')
-		});
 	}
 
 	propagate_error(error, effect);
diff --git a/packages/svelte/tests/runtime-runes/samples/error-boundary-22/Child.svelte b/packages/svelte/tests/runtime-runes/samples/error-boundary-22/Child.svelte
new file mode 100644
index 0000000000..ea60542af9
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/error-boundary-22/Child.svelte
@@ -0,0 +1,3 @@
+<script>
+	throw new Error();
+</script>
diff --git a/packages/svelte/tests/runtime-runes/samples/error-boundary-22/_config.js b/packages/svelte/tests/runtime-runes/samples/error-boundary-22/_config.js
new file mode 100644
index 0000000000..c6be4a8cfd
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/error-boundary-22/_config.js
@@ -0,0 +1,11 @@
+import { flushSync } from 'svelte';
+import { test } from '../../test';
+
+export default test({
+	mode: ['client'],
+	test({ assert, target }) {
+		flushSync();
+
+		assert.htmlEqual(target.innerHTML, '<p>error occurred</p>');
+	}
+});
diff --git a/packages/svelte/tests/runtime-runes/samples/error-boundary-22/main.svelte b/packages/svelte/tests/runtime-runes/samples/error-boundary-22/main.svelte
new file mode 100644
index 0000000000..39b2fb2eb2
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/error-boundary-22/main.svelte
@@ -0,0 +1,15 @@
+<script>
+	import Child from "./Child.svelte"
+</script>
+
+<svelte:boundary>
+	<p>This should be removed</p>
+
+	{#if true}
+		<Child />
+	{/if}
+
+	{#snippet failed()}
+		<p>error occurred</p>
+	{/snippet}
+</svelte:boundary>

From e40e9eb1a444426eb5ab27bf39cbda6225283574 Mon Sep 17 00:00:00 2001
From: "github-actions[bot]"
 <41898282+github-actions[bot]@users.noreply.github.com>
Date: Fri, 18 Apr 2025 12:19:20 -0400
Subject: [PATCH 6/6] Version Packages (#15800)

* Version Packages

* Update packages/svelte/CHANGELOG.md

---------

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>
Co-authored-by: Rich Harris <rich.harris@vercel.com>
---
 .changeset/eleven-roses-speak.md |  5 -----
 .changeset/great-colts-film.md   |  5 -----
 .changeset/pretty-beers-care.md  |  5 -----
 packages/svelte/CHANGELOG.md     | 10 ++++++++++
 packages/svelte/package.json     |  2 +-
 packages/svelte/src/version.js   |  2 +-
 6 files changed, 12 insertions(+), 17 deletions(-)
 delete mode 100644 .changeset/eleven-roses-speak.md
 delete mode 100644 .changeset/great-colts-film.md
 delete mode 100644 .changeset/pretty-beers-care.md

diff --git a/.changeset/eleven-roses-speak.md b/.changeset/eleven-roses-speak.md
deleted file mode 100644
index 0d906f3b5f..0000000000
--- a/.changeset/eleven-roses-speak.md
+++ /dev/null
@@ -1,5 +0,0 @@
----
-'svelte': patch
----
-
-fix: ensure <svelte:boundary> properly removes error content in production mode
diff --git a/.changeset/great-colts-film.md b/.changeset/great-colts-film.md
deleted file mode 100644
index 273509c107..0000000000
--- a/.changeset/great-colts-film.md
+++ /dev/null
@@ -1,5 +0,0 @@
----
-'svelte': patch
----
-
-fix: `update_version` after `delete` if `source` is `undefined` and `prop` in `target`
diff --git a/.changeset/pretty-beers-care.md b/.changeset/pretty-beers-care.md
deleted file mode 100644
index 821bad41c4..0000000000
--- a/.changeset/pretty-beers-care.md
+++ /dev/null
@@ -1,5 +0,0 @@
----
-'svelte': patch
----
-
-fix: emit error on wrong placement of the `:global` block selector
diff --git a/packages/svelte/CHANGELOG.md b/packages/svelte/CHANGELOG.md
index 8c01c71099..cb3b356cc7 100644
--- a/packages/svelte/CHANGELOG.md
+++ b/packages/svelte/CHANGELOG.md
@@ -1,5 +1,15 @@
 # svelte
 
+## 5.28.1
+
+### Patch Changes
+
+- fix: ensure `<svelte:boundary>` properly removes error content in production mode ([#15793](https://github.com/sveltejs/svelte/pull/15793))
+
+- fix: `update_version` after `delete` if `source` is `undefined` and `prop` in `target` ([#15796](https://github.com/sveltejs/svelte/pull/15796))
+
+- fix: emit error on wrong placement of the `:global` block selector ([#15794](https://github.com/sveltejs/svelte/pull/15794))
+
 ## 5.28.0
 
 ### Minor Changes
diff --git a/packages/svelte/package.json b/packages/svelte/package.json
index 784b14ea26..c91fbdd7d3 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": "5.28.0",
+  "version": "5.28.1",
   "type": "module",
   "types": "./types/index.d.ts",
   "engines": {
diff --git a/packages/svelte/src/version.js b/packages/svelte/src/version.js
index 4418204eca..a19a773cd1 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 = '5.28.0';
+export const VERSION = '5.28.1';
 export const PUBLIC_VERSION = '5';