Function invokeRender

packages/next/src/server/lib/router-server.ts:298–369

(
      parsedUrl: NextUrlWithParsedQuery,
      invokePath: string,
      handleIndex: number,
      additionalRequestMeta?: RequestMeta
    )

    const invokedOutputs = new Set<string>()

    async function invokeRender(
      parsedUrl: NextUrlWithParsedQuery,
      invokePath: string,
      handleIndex: number,
      additionalRequestMeta?: RequestMeta
    ) {
      // invokeRender expects /api routes to not be locale prefixed
      // so normalize here before continuing
      if (
        config.i18n &&
        removePathPrefix(invokePath, config.basePath).startsWith(
          `/${getRequestMeta(req, 'locale')}/api`
        )
      ) {
        invokePath = fsChecker.handleLocale(
          removePathPrefix(invokePath, config.basePath)
        ).pathname
      }

      if (
        req.headers['x-nextjs-data'] &&
        fsChecker.getMiddlewareMatchers()?.length &&
        removePathPrefix(invokePath, config.basePath) === '/404'
      ) {
        res.setHeader('x-nextjs-matched-path', parsedUrl.pathname || '')
        res.statusCode = 404
        res.setHeader('content-type', 'application/json')
        res.end('{}')
        return null
      }

      if (!handlers) {
        throw new Error('Failed to initialize render server')
      }

      addRequestMeta(req, 'invokePath', invokePath)
      addRequestMeta(req, 'invokeQuery', parsedUrl.query)
      addRequestMeta(req, 'middlewareInvoke', false)

      for (const key in additionalRequestMeta || {}) {
        addRequestMeta(
          req,
          key as keyof RequestMeta,
          additionalRequestMeta![key as keyof RequestMeta]
        )
      }

      debug('invokeRender', req.url, req.headers)

      try {
        const initResult =
          await renderServer?.instance?.initialize(renderServerOpts)
        try {
          await initResult?.requestHandler(req, res)
        } catch (err) {
          if (err instanceof NoFallbackError) {
            await handleRequest(handleIndex + 1)
            return