Big update!Introducing GitHub Bot Commands. Learn more
Socket
Log inBook a demo

json-parse-even-better-errors

Package Overview
Dependencies
0
Maintainers
6
Versions
7
Issues
File Explorer

Advanced tools

json-parse-even-better-errors

JSON.parse with context information on error

    3.0.0latest

Version published
Maintainers
6
Weekly downloads
20,231,519
decreased by-11.04%

Weekly downloads

Changelog

Source

3.0.0 (2022-10-10)

⚠️ BREAKING CHANGES

  • json-parse-even-better-errors now supports the following semver range for node: ^14.17.0 || ^16.13.0 || >=18.0.0

Features

Readme

Source

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.

It also preserves the newline and indentation styles of the JSON data, by putting them in the object or array in the Symbol.for('indent') and Symbol.for('newline') properties.

Install

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

Table of Contents

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.
  • Attaches the newline character(s) used to the Symbol.for('newline') property on objects and arrays.
  • Attaches the indentation character(s) used to the Symbol.for('indent') property on objects and arrays.

Indentation

To preserve indentation when the file is saved back to disk, use data[Symbol.for('indent')] as the third argument to JSON.stringify, and if you want to preserve windows \r\n newlines, replace the \n chars in the string with data[Symbol.for('newline')].

For example:

const txt = await readFile('./package.json', 'utf8') const data = parseJsonEvenBetterErrors(txt) const indent = Symbol.for('indent') const newline = Symbol.for('newline') // .. do some stuff to the data .. const string = JSON.stringify(data, null, data[indent]) + '\n' const eolFixed = data[newline] === '\n' ? string : string.replace(/\n/g, data[newline]) await writeFile('./package.json', eolFixed)

Indentation is determined by looking at the whitespace between the initial { and [ and the character that follows it. If you have lots of weird inconsistent indentation, then it won't track that or give you any way to preserve it. Whether this is a bug or a feature is debatable ;)

API

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

Works just like JSON.parse, but will include a bit more information when an error happens, and attaches a Symbol.for('indent') and Symbol.for('newline') on objects and arrays. 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.

Keywords

FAQs

What is json-parse-even-better-errors?

JSON.parse with context information on error

Is json-parse-even-better-errors popular?

The npm package json-parse-even-better-errors receives a total of 15,608,805 weekly downloads. As such, json-parse-even-better-errors popularity was classified as popular.

Is json-parse-even-better-errors well maintained?

We found that json-parse-even-better-errors demonstrated a healthy version release cadence and project activity because the last version was released less than a year ago.It has 6 open source maintainers collaborating on the project.

Last updated on 10 Oct 2022

Did you know?

Socket installs a Github app to automatically flag issues on every pull request and report the health of your dependencies. Find out what is inside your node modules and prevent malicious activity before you update the dependencies.

Install Socket
Socket

Product

Subscribe to our newsletter

Get open source security insights delivered straight into your inbox. Be the first to learn about new features and product updates.


  • Terms
  • Privacy
  • Security

Made with ⚡️ by Socket Inc