rsnext/packages/next/client/components/headers.ts

import { RequestCookies } from '../../server/web/spec-extension/cookies'
import { requestAsyncStorage } from './request-async-storage'
import { staticGenerationBailout } from './static-generation-bailout'

export function headers() {
  if (staticGenerationBailout('headers')) {
    return new Headers({})
  }

  const requestStore =
    requestAsyncStorage && 'getStore' in requestAsyncStorage
      ? requestAsyncStorage.getStore()!
      : requestAsyncStorage

  return requestStore.headers
}

export function previewData() {
  if (staticGenerationBailout('previewData')) {
    return {}
  }

  const requestStore =
    requestAsyncStorage && 'getStore' in requestAsyncStorage
      ? requestAsyncStorage.getStore()!
      : requestAsyncStorage
  return requestStore.previewData
}

export function cookies() {
  if (staticGenerationBailout('cookies')) {
    return new RequestCookies(new Headers({}))
  }
  const requestStore =
    requestAsyncStorage && 'getStore' in requestAsyncStorage
      ? requestAsyncStorage.getStore()!
      : requestAsyncStorage

  return requestStore.cookies
}