Function waitForSuccessfulPing

packages/vite/src/client/client.ts:360–412

(socketUrl: string)

}

function waitForSuccessfulPing(socketUrl: string) {
  if (typeof SharedWorker === 'undefined') {
    const visibilityManager: VisibilityManager = {
      currentState: document.visibilityState,
      listeners: new Set(),
    }
    const onVisibilityChange = () => {
      visibilityManager.currentState = document.visibilityState
      for (const listener of visibilityManager.listeners) {
        listener(visibilityManager.currentState)
      }
    }
    document.addEventListener('visibilitychange', onVisibilityChange)
    return waitForSuccessfulPingInternal(socketUrl, visibilityManager)
  }

  // needs to be inlined to
  //   - load the worker after the server is closed
  //   - make it work with backend integrations
  const blob = new Blob(
    [
      '"use strict";',
      `const waitForSuccessfulPingInternal = ${waitForSuccessfulPingInternal.toString()};`,
      `const fn = ${pingWorkerContentMain.toString()};`,
      `fn(${JSON.stringify(socketUrl)})`,
    ],
    { type: 'application/javascript' },
  )
  const objURL = URL.createObjectURL(blob)
  const sharedWorker = new SharedWorker(objURL)
  return new Promise<void>((resolve, reject) => {
    const onVisibilityChange = () => {
      sharedWorker.port.postMessage({ visibility: document.visibilityState })
    }
    document.addEventListener('visibilitychange', onVisibilityChange)

    sharedWorker.port.addEventListener('message', (event) => {
      document.removeEventListener('visibilitychange', onVisibilityChange)
      sharedWorker.port.close()

      const data: { type: 'success' } | { type: 'error'; error: Error } =
        event.data
      if (data.type === 'error') {
        reject(data.error)
        return
      }
      resolve()
    })

    onVisibilityChange()
    sharedWorker.port.start()
  })
}

type VisibilityManager = {
  currentState: DocumentVisibilityState