Merge YAML source translation into destination translation and only add missing entries

add-missing-translations.js

// Little script to add missing source translation into destination translation file so it is easier to maintain

// Usage:
// add-missing-translations src=en dest=fr

const fs = require('fs');
const YAML = require('yaml');

function toKeyValues(args) {
  return args.map(arg => arg.split('='))
  .reduce((args, [value, key]) => {
      args[value] = key;
      return args;
  }, {});
}

var args = toKeyValues(process.argv.slice(2));


const sourceContent = fs.readFileSync(`./${args.src}.yml`, 'utf8');
const src = sourceContent.trim().length > 0 ? YAML.parse(sourceContent) : {};

const destContent = fs.readFileSync(`./${args.dest}.yml`, 'utf8');
const dest = destContent.trim().length > 0 ? YAML.parse(destContent) : {};

// Iterate through source translation feed destination translation
// https://stackoverflow.com/questions/7549574/merge-js-objects-without-overwriting
function deepmerge(object1, object2) {
  var merged = {};
  for (var each in object2) {
    if (object1.hasOwnProperty(each) && object2.hasOwnProperty(each)) {
      if (typeof(object1[each]) == "object" && typeof(object2[each]) == "object") {
        merged[each] = deepmerge(object1[each], object2[each]);
      } else {
        // Original line in the copied example:
        // The purpose was to concatenate value from source and value from destination
        // merged[each] = [object1[each], object2[each]];
        // Instead, we keep the original value
        merged[each] = object1[each];
      }
    } else if(object2.hasOwnProperty(each)) {
      merged[each] = object2[each];
    }
  }
  for (var each in object1) {
    if (!(each in object2) && object1.hasOwnProperty(each)) {
      merged[each] = object1[each];
    }
  }
  return merged;
}

var result = deepmerge(dest, src);
fs.writeFileSync(`./${args.dest}.yml`, YAML.stringify(result), 'utf8');