fix: move validation from parsing to validation

packages/svelte/src/compiler/phases/1-parse/state/element.js

@@ -680,15 +680,6 @@ function read_attribute_value(parser) {
 		];
 	}
 
-	/**
-	 * we need this because if we are not inside a mustache we treat
-	 * the whole thing as a string
-	 * eg.
-	 *
-	 * <input foo=cool{variable} /> it's equal to <input foo="cool{variable}" />
-	 */
-	const mustached = !quote_mark && parser.match('{');
-
 	let value;
 	try {
 		value = read_sequence(
@@ -700,16 +691,6 @@ function read_attribute_value(parser) {
 			},
 			'in attribute value'
 		);
-
-		/**
-		 * if we are in a mustache tag and the value returned is more than one
-		 * expression there's a mismatch in the expression
-		 *
-		 * <input foo={true}} /> or even <input foo={true}something />
-		 */
-		if (mustached && value.length > 1) {
-			e.attribute_invalid_expression(parser.index);
-		}
 	} catch (/** @type {any} */ error) {
 		if (error.code === 'js_parse_error') {
 			// if the attribute value didn't close + self-closing tag

packages/svelte/src/compiler/phases/2-analyze/validation.js

@@ -8,8 +8,8 @@ import * as e from '../../errors.js';
 import {
 	extract_identifiers,
 	get_parent,
-	is_event_attribute,
 	is_expression_attribute,
+	is_quoted_attribute,
 	is_text_attribute,
 	object,
 	unwrap_optional
@@ -58,6 +58,15 @@ function validate_component(node, context) {
 		}
 
 		if (attribute.type === 'Attribute') {
+			if (
+				context.state.analysis.runes &&
+				!is_quoted_attribute(attribute) &&
+				Array.isArray(attribute.value) &&
+				attribute.value.length > 1
+			) {
+				e.attribute_invalid_expression(attribute);
+			}
+
 			if (context.state.analysis.runes && is_expression_attribute(attribute)) {
 				const expression = attribute.value[0].expression;
 				if (expression.type === 'SequenceExpression') {
@@ -107,6 +116,15 @@ function validate_element(node, context) {
 		if (attribute.type === 'Attribute') {
 			const is_expression = is_expression_attribute(attribute);
 
+			if (
+				context.state.analysis.runes &&
+				!is_quoted_attribute(attribute) &&
+				Array.isArray(attribute.value) &&
+				attribute.value.length > 1
+			) {
+				e.attribute_invalid_expression(attribute);
+			}
+
 			if (context.state.analysis.runes && is_expression) {
 				const expression = attribute.value[0].expression;
 				if (expression.type === 'SequenceExpression') {

packages/svelte/src/compiler/utils/ast.js

@@ -44,6 +44,16 @@ export function is_expression_attribute(attribute) {
 	);
 }
 
+/**
+ * Returns true if the attribute is quoted.
+ * @param {import('#compiler').Attribute} attribute
+ * @returns {attribute is import('#compiler').Attribute & { value: [import('#compiler').ExpressionTag] }}
+ */
+export function is_quoted_attribute(attribute) {
+	if (attribute.value === true) return false;
+	return attribute.value.at(-1)?.end !== attribute.end;
+}
+
 /**
  * Returns true if the attribute starts with `on` and contains a single expression node.
  * @param {import('#compiler').Attribute} attribute

packages/svelte/tests/compiler-errors/samples/unbalanced-curly-component/_config.js

@@ -4,6 +4,6 @@ export default test({
 	error: {
 		code: 'attribute_invalid_expression',
 		message: 'Invalid attribute expression',
-		position: [91, 91]
+		position: [101, 116]
 	}
 });

packages/svelte/tests/compiler-errors/samples/unbalanced-curly-component/main.svelte

@@ -1,3 +1,4 @@
+<svelte:options runes />
 <script>
 	import Component from "./Component.svelte";
 </script>

packages/svelte/tests/compiler-errors/samples/unbalanced-curly-element/_config.js

@@ -4,6 +4,6 @@ export default test({
 	error: {
 		code: 'attribute_invalid_expression',
 		message: 'Invalid attribute expression',
-		position: [46, 46]
+		position: [34, 71]
 	}
 });

packages/svelte/tests/compiler-errors/samples/unbalanced-curly-element/main.svelte

@@ -1,3 +1,4 @@
+<svelte:options runes />
 <button
 	onclick={() => console.log('hello')}}
 >