prune-dev.js

// usage: put this in your package.json
// "scripts": {
//   "prepublishOnly": "node prune-dev.js",
//   "postpublish": "git checkout npm-shrinkwrap.json"
// }
const prune = sw => {
  if (sw.dependencies) {
    for (const [name, dep] of Object.entries(sw.dependencies)) {
      if (dep.dev)
        delete sw.dependencies[name]
    }
    if (!Object.keys(sw.dependencies).length)
      delete sw.dependencies
  }
  return sw
}
const f = 'npm-shrinkwrap.json'
const fs = require('fs')
const sw = JSON.parse(fs.readFileSync(f, 'utf8'))
prune(sw)
fs.writeFileSync(f, JSON.stringify(, null, 2))