@segment/analytics-next/src/lib/fetch.ts

Analytics Next (aka Analytics 2.0) is the latest version of Segment’s JavaScript SDK - enabling you to send your data to any tool without having to learn, test, or use a new API every time.

import unfetch from 'unfetch'
import { getGlobal } from './get-global'

/**
 * Wrapper around native `fetch` containing `unfetch` fallback.
 */
export const fetch: typeof global.fetch = (...args) => {
  const global = getGlobal()
  return ((global && global.fetch) || unfetch)(...args)
}