A/B testing
Set up an A/B test by controlling what response is served based on cookies.
function handleRequest(request) { const NAME = "experiment-0"
// The Responses below are placeholders. You can set up a custom path for each test (e.g. /control/somepath ). const TEST_RESPONSE = new Response("Test group") // e.g. await fetch("/test/sompath", request) const CONTROL_RESPONSE = new Response("Control group") // e.g. await fetch("/control/sompath", request)
// Determine which group this requester is in. const cookie = request.headers.get("cookie") if (cookie && cookie.includes(`${NAME}=control`)) { return CONTROL_RESPONSE } else if (cookie && cookie.includes(`${NAME}=test`)) { return TEST_RESPONSE } else { // If there is no cookie, this is a new client. Choose a group and set the cookie. const group = Math.random() < 0.5 ? "test" : "control" // 50/50 split const response = group === "control" ? CONTROL_RESPONSE : TEST_RESPONSE response.headers.append("Set-Cookie", `${NAME}=${group}; path=/`)
return response }}
addEventListener("fetch", event => { event.respondWith(handleRequest(event.request))})