Function createStartHandler

packages/start-server-core/src/createStartHandler.ts:377–679

(
  cbOrOptions: HandlerCallback<AnyRouter> | CreateStartHandlerOptions,
)

 * ```
 */
export function createStartHandler<TRegister = Register>(
  cbOrOptions: HandlerCallback<AnyRouter> | CreateStartHandlerOptions,
): RequestHandler<TRegister> {
  const handlerOptions: FinalManifestOptions =
    typeof cbOrOptions === 'function' ? {} : cbOrOptions
  const cb: HandlerCallback<AnyRouter> =
    typeof cbOrOptions === 'function' ? cbOrOptions : cbOrOptions.handler
  const finalManifestResolver = createFinalManifestResolver({
    ...handlerOptions,
    cacheCreateTransform: process.env.TSS_DEV_SERVER !== 'true',
  })
  const resolveManifestForRequest =
    process.env.TSS_DEV_SERVER === 'true'
      ? finalManifestResolver.resolveUncached
      : finalManifestResolver.resolveCached

  if (process.env.TSS_DEV_SERVER !== 'true') {
    finalManifestResolver.warmup({
      getBaseManifest: () => getBaseManifest(undefined),
    })
  }

  const startRequestResolver: RequestHandler<Register> = async (
    request,
    requestOpts,
  ) => {
    let router: AnyRouter | null = null as AnyRouter | null
    let responseOwnsCleanup = false as boolean

    try {
      // normalizing and sanitizing the pathname here for server, so we always deal with the same format during SSR.
      // during normalization paths like '//posts' are flattened to '/posts'.
      // in these cases we would prefer to redirect to the new path
      const { url, handledProtocolRelativeURL } = getNormalizedURL(request.url)
      const href = url.pathname + url.search + url.hash
      const origin = getOrigin(request)

      if (handledProtocolRelativeURL) {
        return Response.redirect(url, 308)
      }

      const entries = await getEntries()
      const hasStartInstance = !!entries.startEntry.startInstance
      const startOptions: AnyStartInstanceOptions =
        (await entries.startEntry.startInstance?.getOptions()) ||
        ({} as AnyStartInstanceOptions)

      const { hasPluginAdapters, pluginSerializationAdapters } =
        entries.pluginAdapters

      const serializationAdapters = [
        ...(startOptions.serializationAdapters || []),
        ...(hasPluginAdapters ? pluginSerializationAdapters : []),
        ServerFunctionSerializationAdapter,
      ]

      const requestStartOptions = {
        ...startOptions,