@jcbhmr/json-parse-better-error v1.0.0

JSON.parse() better error

⛔ Better error metadata for JSON.parse()

🧙‍♂️ Adds .filename, .lineno, and .colno properties to the SyntaxError \ ⚖️ Just 370 bytes minzipped \ 💻 Works in Node.js and the browser!

Installation

npm install @jcbhmr/json-parse-better-error

import "https://esm.sh/@jcbhmr/json-parse-better-error";

Usage

⚠️ If no btoa() function exists (if you're using Node.js v14) this module will auto-import a global polyfill for it

import "@jcbhmr/json-parse-better-error/global";
import { JSON_parse } from "@jcbhmr/json-parse-better-error";

import "@jcbhmr/json-parse-better-error/global";

JSON.parse(`{ "this is malformed": }`);
// ⛔ Uncaught
// SyntaxError: Unexpected token } in JSON at position 23
// {
//   filename: 'data:application/json;base64,eyAidGhpcyBpcyBtYWxmb3JtZWQiOiB9',
//   lineno: 1,
//   colno: 24
// }

import { JSON_parse } from "@jcbhmr/json-parse-better-error";

// const userInput = myInput.value;
const userInput = `{ "this is invalid": 4.4.4 }`;
let userJSON;
try {
  userJSON = JSON_parse(userInput);
} catch (error) {
  const sourceLine = userInput.split(/\r?\n/g)[error.lineno - 1];
  const pointerLine = " ".repeat(error.colno - 1) + "^ " + error.message;
  alert(sourceLine + "\n" + pointerLine);
}
// { "this is invalid": 4.4.4 }
//                         ^ Unexpected token . in JSON at position 24

Prior art

• zkat/json-parse-better-errors
• npm/json-parse-even-better-errors