From 4aa815f1ec13722f4f0fbc1a0dcbe707fa476294 Mon Sep 17 00:00:00 2001
From: Rich Harris <rich.harris@vercel.com>
Date: Thu, 1 Aug 2024 15:57:40 -0400
Subject: [PATCH] chore: dedupe list of reserved words (#12691)

---
 .../src/compiler/phases/1-parse/index.js      |  4 +-
 .../svelte/src/compiler/phases/constants.js   | 40 -------------
 packages/svelte/src/compiler/phases/scope.js  |  5 +-
 packages/svelte/src/constants.js              | 51 ----------------
 packages/svelte/src/utils.js                  | 59 +++++++++++++++++++
 5 files changed, 64 insertions(+), 95 deletions(-)

diff --git a/packages/svelte/src/compiler/phases/1-parse/index.js b/packages/svelte/src/compiler/phases/1-parse/index.js
index c5808f313a..1bf52cd932 100644
--- a/packages/svelte/src/compiler/phases/1-parse/index.js
+++ b/packages/svelte/src/compiler/phases/1-parse/index.js
@@ -3,11 +3,11 @@
 import { isIdentifierStart, isIdentifierChar } from 'acorn';
 import fragment from './state/fragment.js';
 import { regex_whitespace } from '../patterns.js';
-import { reserved } from '../../../constants.js';
 import full_char_code_at from './utils/full_char_code_at.js';
 import * as e from '../../errors.js';
 import { create_fragment } from './utils/create.js';
 import read_options from './read/options.js';
+import { is_reserved } from '../../../utils.js';
 
 const regex_position_indicator = / \(\d+:\d+\)$/;
 
@@ -219,7 +219,7 @@ export class Parser {
 
 		const identifier = this.template.slice(this.index, (this.index = i));
 
-		if (!allow_reserved && reserved.includes(identifier)) {
+		if (!allow_reserved && is_reserved(identifier)) {
 			e.unexpected_reserved_word(start, identifier);
 		}
 
diff --git a/packages/svelte/src/compiler/phases/constants.js b/packages/svelte/src/compiler/phases/constants.js
index 4046f665ef..8696692e99 100644
--- a/packages/svelte/src/compiler/phases/constants.js
+++ b/packages/svelte/src/compiler/phases/constants.js
@@ -188,43 +188,3 @@ export const EventModifiers = [
 	'self',
 	'trusted'
 ];
-
-export const JsKeywords = [
-	'class',
-	'break',
-	'const',
-	'let',
-	'var',
-	'continue',
-	'if',
-	'for',
-	'while',
-	'do',
-	'new',
-	'static',
-	'true',
-	'false',
-	'void',
-	'with',
-	'yield',
-	'await',
-	'typeof',
-	'throw',
-	'throws',
-	'null',
-	'delete',
-	'default',
-	'catch',
-	'debugger',
-	'case',
-	'arguments',
-	'else',
-	'extends',
-	'export',
-	'import',
-	'extends',
-	'switch',
-	'instanceof',
-	'return',
-	'this'
-];
diff --git a/packages/svelte/src/compiler/phases/scope.js b/packages/svelte/src/compiler/phases/scope.js
index 6051dda570..49ccfed4ec 100644
--- a/packages/svelte/src/compiler/phases/scope.js
+++ b/packages/svelte/src/compiler/phases/scope.js
@@ -12,7 +12,8 @@ import {
 	object,
 	unwrap_pattern
 } from '../utils/ast.js';
-import { JsKeywords, Runes } from './constants.js';
+import { Runes } from './constants.js';
+import { is_reserved } from '../../utils.js';
 
 export class Scope {
 	/** @type {ScopeRoot} */
@@ -148,7 +149,7 @@ export class Scope {
 			this.references.has(name) ||
 			this.declarations.has(name) ||
 			this.root.conflicts.has(name) ||
-			JsKeywords.includes(name)
+			is_reserved(name)
 		) {
 			name = `${preferred_name}_${n++}`;
 		}
diff --git a/packages/svelte/src/constants.js b/packages/svelte/src/constants.js
index 42653d91c1..049a3821a9 100644
--- a/packages/svelte/src/constants.js
+++ b/packages/svelte/src/constants.js
@@ -129,57 +129,6 @@ export function is_capture_event(name, mode = 'exclude-on') {
 		: name !== 'ongotpointercapture' && name !== 'onlostpointercapture';
 }
 
-export const reserved = [
-	'arguments',
-	'await',
-	'break',
-	'case',
-	'catch',
-	'class',
-	'const',
-	'continue',
-	'debugger',
-	'default',
-	'delete',
-	'do',
-	'else',
-	'enum',
-	'eval',
-	'export',
-	'extends',
-	'false',
-	'finally',
-	'for',
-	'function',
-	'if',
-	'implements',
-	'import',
-	'in',
-	'instanceof',
-	'interface',
-	'let',
-	'new',
-	'null',
-	'package',
-	'private',
-	'protected',
-	'public',
-	'return',
-	'static',
-	'super',
-	'switch',
-	'this',
-	'throw',
-	'true',
-	'try',
-	'typeof',
-	'var',
-	'void',
-	'while',
-	'with',
-	'yield'
-];
-
 // we use a list of ignorable runtime warnings because not every runtime warning
 // can be ignored and we want to keep the validation for svelte-ignore in place
 export const IGNORABLE_RUNTIME_WARNINGS = /** @type {const} */ ([
diff --git a/packages/svelte/src/utils.js b/packages/svelte/src/utils.js
index 6e083d5d6d..1ba3dff435 100644
--- a/packages/svelte/src/utils.js
+++ b/packages/svelte/src/utils.js
@@ -39,3 +39,62 @@ const VOID_ELEMENT_NAMES = [
 export function is_void(name) {
 	return VOID_ELEMENT_NAMES.includes(name) || name.toLowerCase() === '!doctype';
 }
+
+const RESERVED_WORDS = [
+	'arguments',
+	'await',
+	'break',
+	'case',
+	'catch',
+	'class',
+	'const',
+	'continue',
+	'debugger',
+	'default',
+	'delete',
+	'do',
+	'else',
+	'enum',
+	'eval',
+	'export',
+	'extends',
+	'false',
+	'finally',
+	'for',
+	'function',
+	'if',
+	'implements',
+	'import',
+	'in',
+	'instanceof',
+	'interface',
+	'let',
+	'new',
+	'null',
+	'package',
+	'private',
+	'protected',
+	'public',
+	'return',
+	'static',
+	'super',
+	'switch',
+	'this',
+	'throw',
+	'true',
+	'try',
+	'typeof',
+	'var',
+	'void',
+	'while',
+	'with',
+	'yield'
+];
+
+/**
+ * Returns `true` if `word` is a reserved JavaScript keyword
+ * @param {string} word
+ */
+export function is_reserved(word) {
+	return RESERVED_WORDS.includes(word);
+}