Function parse

packages/svelte/src/compiler/phases/1-parse/acorn.js:25–71

(source, comments, typescript, is_script)

 * @param {boolean} [is_script]
 */
export function parse(source, comments, typescript, is_script) {
	const acorn = typescript ? TSParser : JSParser;

	const { onComment, add_comments } = get_comment_handlers(
		source,
		/** @type {CommentWithLocation[]} */ (comments)
	);

	// @ts-expect-error
	const parse_statement = acorn.prototype.parseStatement;

	// If we're dealing with a <script> then it might contain an export
	// for something that doesn't exist directly inside but is inside the
	// component instead, so we need to ensure that Acorn doesn't throw
	// an error in these cases
	if (is_script) {
		// @ts-ignore
		acorn.prototype.parseStatement = function (...args) {
			const v = parse_statement.call(this, ...args);
			// @ts-ignore
			this.undefinedExports = {};
			return v;
		};
	}

	try {
		const ast = acorn.parse(source, {
			onComment,
			sourceType: 'module',
			ecmaVersion: 16,
			locations: true
		});

		add_comments(ast);

		return /** @type {Program} */ (ast);
	} catch (err) {
		// TODO the `return` in necessary for TS<7 due to a bug; otherwise
		// the `finally` block is regarded as unreachable
		return handle_parse_error(err);
	} finally {
		if (is_script) {
			// @ts-expect-error
			acorn.prototype.parseStatement = parse_statement;
		}
	}
}

/**
 * @param {Parser} parser