assign.js

'use strict';

function assign(target) {
  const sources = Array.prototype.slice.call(arguments, 1);
  sources.forEach((source) => {
    Object.keys(source).forEach((key) => {
      // If the target key has an object
      if (key in target && target[key] instanceof Object) {
        // and the source key is also an object
        if (source[key] instanceof Object) {
          // then merge them (source overwrites same keys).
          return assign(target[key], source[key]);
        }
      }
      target[key] = source[key];
    });
  });
  return target;
}

function merge(target) {
  const sources = Array.prototype.slice.call(arguments, 1);
  sources.forEach((source) => {
    Object.keys(source).forEach((key) => {
      // If the target key has an object
      if (key in target && target[key] instanceof Object) {
        // and the source key is also an object
        if (source[key] instanceof Object) {
          // then merge them (source overwrites same keys).
          return merge(target[key], source[key]);
        }
        // If the source key is not an object, we don't overwrite the target object.
        return;
      }
      target[key] = source[key];
    });
  });
  return target;
}

module.exports = assign;
assign.merge = merge;