Function preinitStyle

packages/react-dom-bindings/src/server/ReactFizzConfigDOM.js:6584–6671

(
  href: string,
  precedence: ?string,
  options?: ?PreinitStyleOptions,
)

}

function preinitStyle(
  href: string,
  precedence: ?string,
  options?: ?PreinitStyleOptions,
): void {
  const request = resolveRequest();
  if (!request) {
    // In async contexts we can sometimes resolve resources from AsyncLocalStorage. If we can't we can also
    // possibly get them from the stack if we are not in an async context. Since we were not able to resolve
    // the resources for this call in either case we opt to do nothing. We can consider making this a warning
    // but there may be times where calling a function outside of render is intentional (i.e. to warm up data
    // fetching) and we don't want to warn in those cases.
    previousDispatcher.S(/* preinitStyle */ href, precedence, options);
    return;
  }
  const resumableState = getResumableState(request);
  const renderState = getRenderState(request);
  if (href) {
    precedence = precedence || 'default';
    const key = getResourceKey(href);

    let styleQueue = renderState.styles.get(precedence);
    const hasKey = resumableState.styleResources.hasOwnProperty(key);
    const resourceState = hasKey
      ? resumableState.styleResources[key]
      : undefined;
    if (resourceState !== EXISTS) {
      // We are going to create this resource now so it is marked as Exists
      resumableState.styleResources[key] = EXISTS;

      // If this is the first time we've encountered this precedence we need
      // to create a StyleQueue
      if (!styleQueue) {
        styleQueue = {
          precedence: stringToChunk(escapeTextForBrowser(precedence)),
          rules: ([]: Array<Chunk | PrecomputedChunk>),
          hrefs: ([]: Array<Chunk | PrecomputedChunk>),
          sheets: (new Map(): Map<string, StylesheetResource>),
        };
        renderState.styles.set(precedence, styleQueue);
      }

      const resource = {
        state: PENDING,
        props: Object.assign(
          ({
            rel: 'stylesheet',
            href,
            'data-precedence': precedence,
          }: StylesheetProps),
          options,
        ),
      };

      if (resourceState) {
        // When resourceState is truty it is a Preload state. We cast it for clarity
        const preloadState: Preloaded | PreloadedWithCredentials =
          resourceState;