rubico/dist/x/prepend.es.js

[a]synchronous functional programming

/**
 * rubico v2.7.7
 * https://github.com/a-synchronous/rubico
 * (c) 2019-2025 Richard Tong
 * rubico may be freely distributed under the MIT license.
 */

const isString = function (value) {
  return typeof value == 'string'
    || (value != null && value.constructor == String)
}

const isArray = Array.isArray

const prepend = element => function prependFunc(value) {

    if (isArray(value)) {
      if (isArray(element)){
        return [...element, ...value]
      }
      return [element, ...value]
    }

    if (isString(value)){
      if (!isString(element)){
        throw new TypeError(`${element} is not a string`)
      }
      return `${element}${value}`
    }

    throw new TypeError(`${value} is not an Array or string`)
  }

export default prepend