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0.0.2 • Public • Published


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Converts the NPM package lock to the version 1, 2 or 3. There may be tools, which don't support the latest version.

Warning: This is experimental and still in development. Only the conversion to the package lock version 1 works now and only partially.


$ npx package-lock-converter -3c
no conversion needed

$ npm i -g package-lock-converter
$ convert-package-lock -1
  "lockfileVersion": "1",

Command-line usage

Make sure that you have Node.js >= 14.8 installed. Install the package-lock-converter package globally using your favourite package manager to be able to generate and parse build numbers by running convert-package-lock from any directory in PATH:

$ npm i -g package-lock-converter
$ pnpm i -g package-lock-converter
$ yarn global add package-lock-converter

Running convert-package-lock --help prints usage instructions:

Usage: convert-package-lock [options] [--] [<file>]

  -f, --config <file>     read package configuration from the specified file
  -o, --output <file>     write to the specified package lock file
  -t, --to-version <num>  convert the package lock to the specified version
  -1|2|3                  convert the package lock to the specified version
  -c, --check-only        only check if the package lock needs a conversion
  -i, --in-place          modify the input file instead of printing the result
  -p, --[no-]prettify     format a human readable output (default)
  -V, --version           print the version number
  -h, --help              print the usage instructions

The target version is a mandatory option. The default file name of the package
configuration is "package.json". The default file name of the package lock is
"package-lock.json". If "--" is the last argument, the package lock content
will be read from the standard input.

  $ convert-package-lock -1i
  $ convert-package-lock -3 package-lock-preview.json


Bundles for Node.js (CJS, and ESM) are available, incusing TypeScript. They export the function for performing the package lock version conversion.

import { readFile, writeFile } from 'fs/promises'
import { convertPackageLock } from 'package-lock-converter'

// Load the contents of the package configuration and package lock files
const [config, lock] = await Promise.all([
  readFile('package.json', 'utf8'), readFile('package-lock.json', 'utf8')

// Convert the package lock to the version 1 and print the result,
// if the package lock needed the conversion
const result = convertPackageLock(JSON.parse(config), JSON.parse(lock), 1)
if (result) console.log(result)


In lieu of a formal styleguide, take care to maintain the existing coding style. Add unit tests for any new or changed functionality. Lint and test your code using npm test.


Copyright (c) 2023 Ferdinand Prantl

Licensed under the MIT license.


npm i package-lock-converter

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