bump package.json and package-lock.json versions

bump-version.js

#!/usr/bin/env node

const fs = require('fs');
const bumpVersion = process.argv.length >= 3 ? process.argv[2] : undefined;

['./package.json', './package-lock.json'].forEach(fname => {
  let packageJson = fs.readFileSync(fname, 'utf8');
  const [full, semver] = packageJson.match('"version":[ ]*"([0-9]+\.[0-9]+\.[0-9]+)"');
  let [major, minor, patch] = semver.split('.').map(version => parseInt(version));

  if (bumpVersion === 'major') {
    major += 1;
  } else if (bumpVersion === 'minor') {
    minor += 1;
  } else if(bumpVersion === 'patch') {
    patch += 1;
  } else {
    throw Error('usage: bump-version [major/minor/patch]');
  }

  packageJson = packageJson.replace(full, full.replace(semver, `${major}.${minor}.${patch}`));
  fs.writeFileSync(fname, packageJson);
});