Route to a different origin based on origin response

export default {
	async fetch(request) {
		// Send original request to the origin
		const response = await fetch(request);

		// If response is not 200 OK or a redirect, send to another origin
		if (!response.ok && !response.redirected) {
			// First, clone the original request to construct a new request
			const newRequest = new Request(request);
			// Add a header to identify a re-routed request at the new origin
			newRequest.headers.set("X-Rerouted", "1");
			// Clone the original URL
			const url = new URL(request.url);
			// Send request to a different origin / hostname
			url.hostname = "example.com";
			// Serve response to the new request from the origin
			return await fetch(url, newRequest);
		}

		// If response is 200 OK or a redirect, serve it
		return response;
	},
};