A very simple JSONP package

jsonp.ts

/**
 * A very simple JSONP package
 * @author Dragon-Fish
 * @license MIT
 */

/**
 * jsonp
 * @example
 * ```ts
 * jsonp('https://zh.wikipedia.org/w/api.php', {
 *   action: 'query',
 *   format: 'json',
 * }).then(console.info)
 * ```
 */
export async function jsonp<T = any>(
  endpoint: string,
  params: Record<string, string> = {},
  options?: { cbParamName: string }
): Promise<T> {
  const url = new URL(endpoint)
  const cbParamName = options?.cbParamName || 'callback'
  let cbFnName = params[cbParamName]
  if (!cbFnName) {
    cbFnName = params[cbParamName] =
      'JSONP_' + Math.random().toString(16).slice(2)
  }
  url.search = '' + new URLSearchParams(params)
  const script = document.createElement('script')
  return new Promise<T>((resolve, reject) => {
    ;(window as any)[cbFnName] = (data: T) => resolve(data)
    script.src = '' + url
    document.body.appendChild(script)
    script.addEventListener('error', (e) => {
      reject(e)
    })
  }).finally(() => {
    document.body.removeChild(script)
    delete (window as any)[cbFnName]
  })
}