add loose option

Author: dummdidumm

packages/svelte/src/compiler/errors.js

@@ -14,7 +14,7 @@ class InternalCompileError extends Error {
 	 */
 	constructor(code, message, position) {
 		super(message);
-		this.stack = ''; // avoid unnecessary noise; don't set it as a class property or it becomes enumerable
+		// this.stack = ''; // avoid unnecessary noise; don't set it as a class property or it becomes enumerable
 		// We want to extend from Error so that various bundler plugins properly handle it.
 		// But we also want to share the same object shape with that of warnings, therefore
 		// we create an instance of the shared class an copy over its properties.

packages/svelte/src/compiler/index.js

@@ -99,15 +99,15 @@ export function compileModule(source, options) {
  * `modern` will become `true` by default in Svelte 6, and the option will be removed in Svelte 7.
  *
  * @param {string} source
- * @param {{ filename?: string; rootDir?: string; modern?: boolean }} [options]
+ * @param {{ filename?: string; rootDir?: string; modern?: boolean; loose?: boolean }} [options]
  * @returns {AST.Root | LegacyRoot}
  */
-export function parse(source, { filename, rootDir, modern } = {}) {
+export function parse(source, { filename, rootDir, modern, loose } = {}) {
 	source = remove_bom(source);
 	state.reset_warning_filter(() => false);
 	state.reset(source, { filename: filename ?? '(unknown)', rootDir });
 
-	const ast = _parse(source);
+	const ast = _parse(source, loose);
 	return to_public_ast(source, ast, modern);
 }
 

packages/svelte/src/compiler/phases/1-parse/index.js

@@ -22,6 +22,13 @@ export class Parser {
 	 */
 	template;
 
+	/**
+	 * Whether or not we're in loose parsing mode, in which
+	 * case we try to continue parsing as much as possible
+	 * @type {boolean}
+	 */
+	loose;
+
 	/** */
 	index = 0;
 
@@ -43,12 +50,16 @@ export class Parser {
 	/** @type {LastAutoClosedTag | undefined} */
 	last_auto_closed_tag;
 
-	/** @param {string} template */
-	constructor(template) {
+	/**
+	 * @param {string} template
+	 * @param {boolean} loose
+	 */
+	constructor(template, loose) {
 		if (typeof template !== 'string') {
 			throw new TypeError('Template must be a string');
 		}
 
+		this.loose = loose;
 		this.template = template.trimEnd();
 
 		let match_lang;
@@ -274,10 +285,11 @@ export class Parser {
 
 /**
  * @param {string} template
+ * @param {boolean} [loose]
  * @returns {AST.Root}
  */
-export function parse(template) {
-	const parser = new Parser(template);
+export function parse(template, loose = false) {
+	const parser = new Parser(template, loose);
 	return parser.root;
 }