meriyah

import { parse, isParseError } from 'meriyah'; import type { Program } from 'estree'; // Assuming ESTree types are needed for the result const javascriptCode = ` // This is a complex JavaScript module demonstrating various features. import { someUtil } from './utils.js'; @debounce(300) class MyClass { #privateField = 42; // Private class field (ES2022) constructor(name) { this.name = name; } // A method with decorators (TC39 Stage 3, requires 'next' option) @log greet(param) { console.log(`Hello, ${this.name}! ${param}`); return someUtil(this.#privateField); } } export const instance = new MyClass('Meriyah User'); // Example of Annex B feature (non-strict mode) // function foo() { 'use strict'; with (obj) {} } // This would error in strict mode // A regular expression with newer features (requires Node.js >= 24 for full validation) const regex = /(?<word>\w+)/d; if ("test".match(regex)) { console.log("Matched!"); } `; try { const ast: Program = parse(javascriptCode, { sourceType: 'module', // Parse as an ES module ranges: true, // Include start/end offsets for each node loc: true, // Include line/column location information next: true, // Enable TC39 Stage 3 proposals (e.g., Decorators) jsx: false, // Explicitly disable JSX (if not needed) webcompat: true, // Enable web compatibility (Annex B) validateRegex: true, // Validate regular expressions with the current JS runtime }); console.log('Successfully parsed AST:'); // console.log(JSON.stringify(ast, null, 2)); // Uncomment to see the full AST console.log(`Program type: ${ast.type}`); console.log(`First statement type: ${ast.body[0].type}`); } catch (e: any) { if (isParseError(e)) { console.error(`Meriyah Parse Error: ${e.message} at line ${e.loc?.line}, column ${e.loc?.column}`); } else { console.error('An unexpected error occurred:', e.message); } }