@onesy/utils/esm/merge.js

Utils

import is from './is';
import copy from './copy';
const optionsDefault = {
  copy: false,
  merge: {
    array: false
  }
};

const merge = function (target, source) {
  let options_ = arguments.length > 2 && arguments[2] !== undefined ? arguments[2] : {};
  const options = { ...optionsDefault,
    ...options_
  };

  if (options.merge.array && is('array', target) && is('array', source)) {
    const length = Math.max(target.length, source.length);

    for (let i = 0; i < length; i++) {
      if (target[i] === undefined) target[i] = source[i];
      if (is('object', target[i]) && is('object', source[i]) || is('array', target[i]) && is('array', source[i])) target[i] = merge(target[i], source[i], options);
    }
  }

  if (is('object', target) && is('object', source)) {
    Object.keys(source).forEach(key => {
      // We only care about direct target object properties
      // not about inherited properties from a prototype chain
      if (target.hasOwnProperty(key)) {
        if (is('object', target[key]) && is('object', source[key])) target[key] = merge(target[key], source[key], options);
      } else target[key] = options.copy ? copy(source[key]) : source[key];
    });
  }

  return target;
};

export default merge;