Using JSONPatch to programatically update a package.json

index.js

var fs = require('fs')
var jsonpatch = require('fast-json-patch')
var pkg = require('./package.json')
var patch = require('./patch')(pkg)

var patches = jsonpatch.compare(pkg, patch)
  // We don’t want to remove keys missing from our patch.
  .filter(function (item) {
    return item.op !== 'remove'
  })

// The value of `pkg` is mutated.
jsonpatch.apply(pkg, patches)

// Use proper formatting.
var patched = JSON.stringify(
  pkg, null, 2
)

fs.writeFile('./package.json', patched, function (err) {
  console.log(err ? err.message : patched)
})

package.json

{
  "name": "my-package",
  "version": "0.0.6",
  "dependencies": {
    "fast-json-patch": "^0.5.0"
  }
}

patch.js

module.exports = function (og) {
  return {
    // Bump the patch version.
    version: (function bump () {
      var version = og.version.split('.').map(Number)
      version[version.length - 1]++
      return version.join('.')
    })()
  }
}