How to hot reload a virtual module in a Vite plugin

vite-hot-reload-virtual-module-plugin.js

function vitePlugin() {
  const virtualModuleDependency = 'virtual-module-conf.json';
  const virtualModuleId = 'virtual:module';
  const resolveVirtualId = (id) => '\0' + id;
  
  let virtualModuleContent;
  async function refreshVirtualModuleContent(reader) {
    const json = JSON.parse(await reader());
    virtualModuleContent = `export default ${JSON.stringify(json.value)};`;
  }
  async function loadVirtualModule() {
    await refreshVirtualModuleContent(fs.readFile.bind(fs, virtualModuleDependecy));
    return virtualModuleContent;
  }
  
  return {
    name: 'vite-plugin',
    resolveId(id) {
      if (id === virtualModuleId) {
        return resolveVirtualId(virtualModuleId);
      }
    },
    load(id) {
      if (id === resolveVirtualId(virtualModuleId)) {
        return loadVirtualModule();
      }
    },
    handleHotUpdate({server, file, modules, read}) {
      if (!file.endsWith(virtualModuleDependency) {
        return modules;
      }
      
      refreshVirtualModuleContent(read);
      const virtualModule = server.moduleGraph.getModuleById(
        resolveVirtualId(virtualModuleId)
      );
      
      return [...modules, virtualModule];
    }
  };
}