W3Schools Tryit Editor

type UserRole = 'admin' | 'editor' | 'viewer';

const currentUser = {
  id: 1,
  name: 'John Doe',
  roles: ['viewer'] as UserRole[]
};

class DocumentService {
  @AllowedRoles('admin', 'editor', 'viewer')
  viewDocument(id: string) {
    console.log(`Viewing document ${id}`);
  }
  @AllowedRoles('admin', 'editor')
  deleteDocument(id: string) {
    console.log(`Document ${id} deleted`);
  }
}

const docService = new DocumentService();
try {
  docService.viewDocument('doc123');
  docService.deleteDocument('doc123');
} catch (error: any) {
  console.log(error.message);
}

Expected console output:

Viewing document doc123
User John Doe is not authorized to call deleteDocument