json-parse-even-better-errors

json-parse-even-better-errors is a Node.js library for getting nicer errors out of JSON.parse(), including context and position of the parse errors.

Install

$ npm install --save json-parse-even-better-errors

Table of Contents

• Example
• Features
• Contributing
• API
  • parse

Example

const parseJson = require('json-parse-even-better-errors')

parseJson('"foo"') // returns the string 'foo'
parseJson('garbage') // more useful error message
parseJson.noExceptions('garbage') // returns undefined

Features

• Like JSON.parse, but the errors are better.
• Strips a leading byte-order-mark that you sometimes get reading files.
• Has a noExceptions method that returns undefined rather than throwing.

API

parse(txt, reviver = null, context = 20)

Works just like JSON.parse, but will include a bit more information when an error happens. This throws a JSONParseError.

parse.noExceptions(txt, reviver = null)

Works just like JSON.parse, but will return undefined rather than throwing an error.

class JSONParseError(er, text, context = 20, caller = null)

Extends the JavaScript SyntaxError class to parse the message and provide better metadata.

Pass in the error thrown by the built-in JSON.parse, and the text being parsed, and it'll parse out the bits needed to be helpful.

context defaults to 20.

Set a caller function to trim internal implementation details out of the stack trace. When calling parseJson, this is set to the parseJson function. If not set, then the constructor defaults to itself, so the stack trace will point to the spot where you call new JSONParseError.