Function renderImpl

packages/next/src/server/base-server.ts:1895–1946

(
    req: ServerRequest,
    res: ServerResponse,
    pathname: string,
    query: NextParsedUrlQuery = {},
    parsedUrl?: NextUrlWithParsedQuery,
    internalRender = false
  )

  }

  private async renderImpl(
    req: ServerRequest,
    res: ServerResponse,
    pathname: string,
    query: NextParsedUrlQuery = {},
    parsedUrl?: NextUrlWithParsedQuery,
    internalRender = false
  ): Promise<void> {
    if (!pathname.startsWith('/')) {
      console.warn(
        `Cannot render page with path "${pathname}", did you mean "/${pathname}"?. See more info here: https://nextjs.org/docs/messages/render-no-starting-slash`
      )
    }

    if (
      this.serverOptions.customServer &&
      pathname === '/index' &&
      !(await this.hasPage('/index'))
    ) {
      // maintain backwards compatibility for custom server
      // (see custom-server integration tests)
      pathname = '/'
    }

    const ua = req.headers['user-agent'] || ''
    this.renderOpts.botType = getBotType(ua)

    // we allow custom servers to call render for all URLs
    // so check if we need to serve a static _next file or not.
    // we don't modify the URL for _next/data request but still
    // call render so we special case this to prevent an infinite loop
    if (
      !internalRender &&
      !this.minimalMode &&
      !getRequestMeta(req, 'isNextDataReq') &&
      (req.url?.match(/^\/_next\//) ||
        (this.hasStaticDir && req.url!.match(/^\/static\//)))
    ) {
      return this.handleRequest(req, res, parsedUrl)
    }

    if (isBlockedPage(pathname)) {
      return this.render404(req, res, parsedUrl)
    }

    return this.pipe((ctx) => this.renderToResponse(ctx), {
      req,
      res,
      pathname,
      query,
    })
  }

  protected async getStaticPaths({
    pathname,