jsonrepair

Repair invalid JSON documents.

Try it out in a minimal demo: https://josdejong.github.io/jsonrepair/

Use it in a full-fledged application: https://jsoneditoronline.org

Read the background article "How to fix JSON and validate it with ease"

The following issues can be fixed:

• Add missing quotes around keys
• Add missing escape characters
• Add missing commas
• Add missing closing brackets
• Repair truncated JSON
• Replace single quotes with double quotes
• Replace special quote characters like “...” with regular double quotes
• Replace special white space characters with regular spaces
• Replace Python constants None, True, and False with null, true, and false
• Strip trailing commas
• Strip comments like /* ... */ and // ...
• Strip JSONP notation like callback({ ... })
• Strip escape characters from an escaped string like {\"stringified\": \"content\"}
• Strip MongoDB data types like NumberLong(2) and ISODate("2012-12-19T06:01:17.171Z")
• Concatenate strings like "long text" + "more text on next line"
• Turn newline delimited JSON into a valid JSON array, for example:

  { "id": 1, "name": "John" }
  { "id": 2, "name": "Sarah" }

Note that in practice, the jsonrepair library can handle file sizes up to 512 MB.

Install

$ npm install jsonrepair

Note that in the lib folder, there are builds for ESM, UMD, and CommonJs.

Use

Use with an ES modules import (recommended):

import { jsonrepair } from 'jsonrepair'

try {
  // The following is invalid JSON: is consists of JSON contents copied from 
  // a JavaScript code base, where the keys are missing double quotes, 
  // and strings are using single quotes:
  const json = "{name: 'John'}"
  
  const repaired = jsonrepair(json)
  
  console.log(repaired) // '{"name": "John"}'
} catch (err) {
  console.error(err)
}

Use in CommonJS (not recommended):

const { jsonrepair } = require('jsonrepair')
const json = "{name: 'John'}"
console.log(jsonrepair(json)) // '{"name": "John"}'

Use with UMD in the browser (not recommended):

<script src="/node_modules/jsonrepair/lib/umd/jsonrepair.js"></script>
<script>
  const { jsonrepair } = JSONRepair
  const json = "{name: 'John'}"
  console.log(jsonrepair(json)) // '{"name": "John"}'
</script>

API

// @throws JSONRepairError 
jsonrepair(json: string) : string

The function jsonrepair throws an exception JSONRepairError when an issue is encountered which could not be solved. When no error is thrown, the output will be valid JSON.

Command Line Interface (CLI)

When jsonrepair is installed globally using npm, it can be used on the command line. To install jsonrepair globally:

$ npm install -g jsonrepair

Usage:

$ jsonrepair [filename] {OPTIONS}

Options:

--version, -v       Show application version
--help,    -h       Show help

Example usage:

$ jsonrepair broken.json                         # Repair a file, output to console
$ jsonrepair broken.json > repaired.json         # Repair a file, output to file
$ jsonrepair broken.json --overwrite             # Repair a file, replace the file itself
$ cat broken.json | jsonrepair                   # Repair data from an input stream
$ cat broken.json | jsonrepair > repaired.json   # Repair data from an input stream, output to file

Alternatives:

Similar libraries:

• https://github.com/RyanMarcus/dirty-json

Develop

To build the library (ESM, CommonJs, and UMD output in the folder lib):

$ npm install 
$ npm run build

To run the unit tests:

$ npm test

To run the linter (eslint):

$ npm run lint

To automatically fix linter issues:

$ npm run format

To run the linter, build all, and run unit tests and integration tests:

$ npm run build-and-test

Release

To release a new version:

$ npm run release

This will:

• lint
• test
• build
• increment the version number
• push the changes to git, add a git version tag
• publish the npm package

To try the build and see the change list without actually publishing:

$ npm run release-dry-run

License

Released under the ISC license.