Function preloadModule

packages/react-dom-bindings/src/server/ReactFizzConfigDOM.js:6511–6582

(
  href: string,
  options?: ?PreloadModuleImplOptions,
)

}

function preloadModule(
  href: string,
  options?: ?PreloadModuleImplOptions,
): 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.m(/* preloadModule */ href, options);
    return;
  }
  const resumableState = getResumableState(request);
  const renderState = getRenderState(request);
  if (href) {
    const key = getResourceKey(href);
    const as =
      options && typeof options.as === 'string' ? options.as : 'script';

    let resource;
    switch (as) {
      case 'script': {
        if (resumableState.moduleScriptResources.hasOwnProperty(key)) {
          // we can return if we already have this resource
          return;
        }
        resource = ([]: Resource);
        resumableState.moduleScriptResources[key] =
          options &&
          (typeof options.crossOrigin === 'string' ||
            typeof options.integrity === 'string')
            ? [options.crossOrigin, options.integrity]
            : PRELOAD_NO_CREDS;
        renderState.preloads.moduleScripts.set(key, resource);
        break;
      }
      default: {
        const hasAsType =
          resumableState.moduleUnknownResources.hasOwnProperty(as);
        let resources;
        if (hasAsType) {
          resources = resumableState.unknownResources[as];
          if (resources.hasOwnProperty(key)) {
            // we can return if we already have this resource
            return;
          }
        } else {
          resources = ({}: ResumableState['moduleUnknownResources']['asType']);
          resumableState.moduleUnknownResources[as] = resources;
        }
        resource = ([]: Resource);
        resources[key] = PRELOAD_NO_CREDS;
      }
    }

    pushLinkImpl(