Function renderToStringImpl

packages/react-dom/src/server/ReactDOMLegacyServerImpl.js:35–101

(
  children: ReactNodeList,
  options: void | ServerOptions,
  generateStaticMarkup: boolean,
  abortReason: string,
)

}

function renderToStringImpl(
  children: ReactNodeList,
  options: void | ServerOptions,
  generateStaticMarkup: boolean,
  abortReason: string,
): string {
  let didFatal = false;
  let fatalError = null;
  let result = '';
  const destination = {
    // $FlowFixMe[missing-local-annot]
    push(chunk) {
      if (chunk !== null) {
        result += chunk;
      }
      return true;
    },
    // $FlowFixMe[missing-local-annot]
    destroy(error) {
      didFatal = true;
      fatalError = error;
    },
  };

  let readyToStream = false;
  function onShellReady() {
    readyToStream = true;
  }
  const resumableState = createResumableState(
    options ? options.identifierPrefix : undefined,
    undefined,
  );
  const request = createRequest(
    children,
    resumableState,
    createRenderState(resumableState, generateStaticMarkup),
    createRootFormatContext(),
    Infinity,
    onError,
    undefined,
    onShellReady,
    undefined,
    undefined,
    undefined,
  );
  startWork(request);
  // If anything suspended and is still pending, we'll abort it before writing.
  // That way we write only client-rendered boundaries from the start.
  abort(request, abortReason);
  startFlowing(request, destination);
  if (didFatal && fatalError !== abortReason) {
    throw fatalError;
  }

  if (!readyToStream) {
    // Note: This error message is the one we use on the client. It doesn't
    // really make sense here. But this is the legacy server renderer, anyway.
    // We're going to delete it soon.