getFieldValues

/**
 *
 * @param {Object} obj source object to be traversed
 * @param {RegExp} fieldName regular expression that represents a required property
 */
export const getFieldValues = (obj, fieldName) => {
  if (Object.keys(obj).length === 0) {
    return
  }

  const keys = Object.keys(obj)
  const values = keys.reduce((acc, key) => {
    
    // no need in non-iterable properties
    if (!obj.hasOwnProperty(key)) {
      return acc
    }

    // the property the script is looking for
    if (fieldName.test(key)) {
      
      return typeof obj[key] === 'string' ? [...acc, obj[key]] : [...acc, ...obj[key]]
    }

    const currentValue = obj[key]
    if (typeof currentValue === 'number' || typeof currentValue === 'string') {
      return acc
    }

    // do this block only for objects
    if (!Array.isArray(currentValue)) {
      const nextLevelValues = getFieldValues(currentValue, fieldName)
      console.log('nextLevelValues: ', nextLevelValues)
      return nextLevelValues && nextLevelValues.length > 0 ? [...acc, ...nextLevelValues] : acc
    }

    return acc
  }, [])

  return values
}