From 9a97d5c547b4c041d9931b95c650f08168054aa2 Mon Sep 17 00:00:00 2001
From: Simon H <5968653+dummdidumm@users.noreply.github.com>
Date: Fri, 17 Nov 2023 13:31:07 +0100
Subject: [PATCH] fix: ignore expressions in top level script/style tag
 attributes (#9498)

Related to sveltejs/language-tools#2204 / sveltejs/language-tools#2039
---
 .changeset/ten-ducks-jump.md                  |   5 +
 .../svelte/src/compiler/parse/state/tag.js    |  44 ++++-
 .../input.svelte                              |   5 +
 .../output.json                               | 150 ++++++++++++++++++
 4 files changed, 196 insertions(+), 8 deletions(-)
 create mode 100644 .changeset/ten-ducks-jump.md
 create mode 100644 packages/svelte/test/parser/samples/script-attribute-with-curly-braces/input.svelte
 create mode 100644 packages/svelte/test/parser/samples/script-attribute-with-curly-braces/output.json

diff --git a/.changeset/ten-ducks-jump.md b/.changeset/ten-ducks-jump.md
new file mode 100644
index 0000000000..0bd70fbe17
--- /dev/null
+++ b/.changeset/ten-ducks-jump.md
@@ -0,0 +1,5 @@
+---
+'svelte': patch
+---
+
+fix: ignore expressions in top level script/style tag attributes
diff --git a/packages/svelte/src/compiler/parse/state/tag.js b/packages/svelte/src/compiler/parse/state/tag.js
index c0df00df92..37281c5156 100644
--- a/packages/svelte/src/compiler/parse/state/tag.js
+++ b/packages/svelte/src/compiler/parse/state/tag.js
@@ -161,8 +161,9 @@ export default function tag(parser) {
 	 * @type {Set<string>}
 	 */
 	const unique_names = new Set();
+	const is_top_level_script_or_style = specials.has(name) && parser.stack.length === 1;
 	let attribute;
-	while ((attribute = read_attribute(parser, unique_names))) {
+	while ((attribute = read_attribute(parser, unique_names, is_top_level_script_or_style))) {
 		element.attributes.push(attribute);
 		parser.allow_whitespace();
 	}
@@ -196,8 +197,7 @@ export default function tag(parser) {
 		}
 		element.tag = definition.value[0].data || definition.value[0].expression;
 	}
-	// special cases – top-level <script> and <style>
-	if (specials.has(name) && parser.stack.length === 1) {
+	if (is_top_level_script_or_style) {
 		const special = specials.get(name);
 		parser.eat('>', true);
 		const content = special.read(parser, start, element.attributes);
@@ -280,8 +280,9 @@ const regex_starts_with_quote_characters = /^["']/;
 /**
  * @param {import('../index.js').Parser} parser
  * @param {Set<string>} unique_names
+ * @param {boolean} is_static If `true`, `{` and `}` are not treated as delimiters for expressions
  */
-function read_attribute(parser, unique_names) {
+function read_attribute(parser, unique_names, is_static) {
 	const start = parser.index;
 
 	/**
@@ -293,7 +294,7 @@ function read_attribute(parser, unique_names) {
 		}
 		unique_names.add(name);
 	}
-	if (parser.eat('{')) {
+	if (!is_static && parser.eat('{')) {
 		parser.allow_whitespace();
 		if (parser.eat('...')) {
 			const expression = read_expression(parser);
@@ -348,12 +349,12 @@ function read_attribute(parser, unique_names) {
 	let value = true;
 	if (parser.eat('=')) {
 		parser.allow_whitespace();
-		value = read_attribute_value(parser);
+		value = read_attribute_value(parser, is_static);
 		end = parser.index;
 	} else if (parser.match_regex(regex_starts_with_quote_characters)) {
 		parser.error(parser_errors.unexpected_token('='), parser.index);
 	}
-	if (type) {
+	if (!is_static && type) {
 		const [directive_name, ...modifiers] = name.slice(colon_index + 1).split('|');
 		if (directive_name === '') {
 			parser.error(parser_errors.empty_directive_name(type), start + colon_index + 1);
@@ -436,10 +437,37 @@ function get_directive_type(name) {
 	if (name === 'in' || name === 'out' || name === 'transition') return 'Transition';
 }
 
+const regex_attribute_value = /^(?:"([^"]*)"|'([^'])*'|([^>\s]))/;
+
 /**
  * @param {import('../index.js').Parser} parser
+ * @param {boolean} is_static If `true`, `{` and `}` are not treated as delimiters for expressions
  */
-function read_attribute_value(parser) {
+function read_attribute_value(parser, is_static) {
+	if (is_static) {
+		let value = parser.match_regex(regex_attribute_value);
+		if (!value) {
+			parser.error(parser_errors.missing_attribute_value);
+		}
+
+		parser.index += value.length;
+
+		const quoted = value[0] === '"' || value[0] === "'";
+		if (quoted) {
+			value = value.slice(1, -1);
+		}
+
+		return [
+			{
+				start: parser.index - value.length - (quoted ? 1 : 0),
+				end: quoted ? parser.index - 1 : parser.index,
+				type: 'Text',
+				raw: value,
+				data: decode_character_references(value, true)
+			}
+		];
+	}
+
 	const quote_mark = parser.eat("'") ? "'" : parser.eat('"') ? '"' : null;
 	if (quote_mark && parser.eat(quote_mark)) {
 		return [
diff --git a/packages/svelte/test/parser/samples/script-attribute-with-curly-braces/input.svelte b/packages/svelte/test/parser/samples/script-attribute-with-curly-braces/input.svelte
new file mode 100644
index 0000000000..423b056e94
--- /dev/null
+++ b/packages/svelte/test/parser/samples/script-attribute-with-curly-braces/input.svelte
@@ -0,0 +1,5 @@
+<script generics="T extends { yes: boolean }">
+	let name = 'world';
+</script>
+
+<h1>Hello {name}!</h1>
\ No newline at end of file
diff --git a/packages/svelte/test/parser/samples/script-attribute-with-curly-braces/output.json b/packages/svelte/test/parser/samples/script-attribute-with-curly-braces/output.json
new file mode 100644
index 0000000000..af4ec56a68
--- /dev/null
+++ b/packages/svelte/test/parser/samples/script-attribute-with-curly-braces/output.json
@@ -0,0 +1,150 @@
+{
+	"html": {
+		"start": 79,
+		"end": 101,
+		"type": "Fragment",
+		"children": [
+			{
+				"start": 77,
+				"end": 79,
+				"type": "Text",
+				"raw": "\n\n",
+				"data": "\n\n"
+			},
+			{
+				"start": 79,
+				"end": 101,
+				"type": "Element",
+				"name": "h1",
+				"attributes": [],
+				"children": [
+					{
+						"start": 83,
+						"end": 89,
+						"type": "Text",
+						"raw": "Hello ",
+						"data": "Hello "
+					},
+					{
+						"start": 89,
+						"end": 95,
+						"type": "MustacheTag",
+						"expression": {
+							"type": "Identifier",
+							"start": 90,
+							"end": 94,
+							"loc": {
+								"start": {
+									"line": 5,
+									"column": 11
+								},
+								"end": {
+									"line": 5,
+									"column": 15
+								}
+							},
+							"name": "name"
+						}
+					},
+					{
+						"start": 95,
+						"end": 96,
+						"type": "Text",
+						"raw": "!",
+						"data": "!"
+					}
+				]
+			}
+		]
+	},
+	"instance": {
+		"type": "Script",
+		"start": 0,
+		"end": 77,
+		"context": "default",
+		"content": {
+			"type": "Program",
+			"start": 46,
+			"end": 68,
+			"loc": {
+				"start": {
+					"line": 1,
+					"column": 0
+				},
+				"end": {
+					"line": 3,
+					"column": 0
+				}
+			},
+			"body": [
+				{
+					"type": "VariableDeclaration",
+					"start": 48,
+					"end": 67,
+					"loc": {
+						"start": {
+							"line": 2,
+							"column": 1
+						},
+						"end": {
+							"line": 2,
+							"column": 20
+						}
+					},
+					"declarations": [
+						{
+							"type": "VariableDeclarator",
+							"start": 52,
+							"end": 66,
+							"loc": {
+								"start": {
+									"line": 2,
+									"column": 5
+								},
+								"end": {
+									"line": 2,
+									"column": 19
+								}
+							},
+							"id": {
+								"type": "Identifier",
+								"start": 52,
+								"end": 56,
+								"loc": {
+									"start": {
+										"line": 2,
+										"column": 5
+									},
+									"end": {
+										"line": 2,
+										"column": 9
+									}
+								},
+								"name": "name"
+							},
+							"init": {
+								"type": "Literal",
+								"start": 59,
+								"end": 66,
+								"loc": {
+									"start": {
+										"line": 2,
+										"column": 12
+									},
+									"end": {
+										"line": 2,
+										"column": 19
+									}
+								},
+								"value": "world",
+								"raw": "'world'"
+							}
+						}
+					],
+					"kind": "let"
+				}
+			],
+			"sourceType": "module"
+		}
+	}
+}