Dynamic Origin Handling

You might want to dynamically determine whether to allow a request based on the origin. Here’s an example that allows origins based on a list or pattern:

const allowedOrigins = ['http://example.com', 'http://another-example.com'];

const corsOptions = {
  origin: (origin, callback) => {
    if (allowedOrigins.includes(origin) || !origin) { // Handle no origin (e.g., CURL requests)
      callback(null, true);
    } else {
      callback(new Error('Not allowed by CORS'));
    }
  },
  methods: 'GET,POST,PUT,DELETE,OPTIONS',
  allowedHeaders: 'Content-Type,Authorization',
  credentials: true,
};

app.use(cors(corsOptions));