convert given nested object to the plain one

convert-plain-object.js

function convertPlainObject (nestedObj, baseKey = '', result = {}) {
  Object.entries(nestedObj).forEach(([key, value]) => {
    if (typeof value === 'object') {
      return convertPlainObject(value, baseKey === '' ? key : `${baseKey}.${key}`, result);
    }

    result[`${baseKey}.${key}`] = value;
  });

  return result;
}