Edge Developer Platform
  • Edge Functions
    • Overview
    • Getting Started
    • Operation Guide
      • Function Management
      • Function Trigger
    • Runtime APIs
      • addEventListener
      • Cache
      • Cookies
      • Encoding
      • Fetch
      • FetchEvent
      • Headers
      • Request
      • Response
      • Streams
        • ReadableStream
        • ReadableStreamBYOBReader
        • ReadableStreamDefaultReader
        • TransformStream
        • WritableStream
        • WritableStreamDefaultWriter
      • Web Crypto
      • Web standards
      • Images
        • ImageProperties
    • Sample Functions
      • Returning an HTML Page
      • Returning a JSON Object
      • Fetch Remote Resources
      • Authenticating a Request Header
      • Modifying a Response Header
      • Performing an A/B Test
      • Setting Cookies
      • Performing Redirect Based on the Request Location
      • Using the Cache API
      • Caching POST Requests
      • Responding in Streaming Mode
      • Merging Resources and Responding in Streaming Mode
      • Protecting Data from Tampering
      • Rewriting a m3u8 File and Configuring Authentication
      • Adaptive Image Resize
      • Image Adaptive WebP
      • Customize Referer restriction rules
      • Remote Authentication
      • HMAC Digital Signature
      • Naming a Downloaded File
      • Obtaining Client IP Address
    • Best Practices
      • Adaptive Image Format Conversion via Edge Functions
このページは現在英語版のみで提供されており、日本語版も近日中に提供される予定です。ご利用いただきありがとうございます。

Performing an A/B Test

In this example, cookies are used to store session information and perform A/B testing on requests. This example demonstrates how to use an edge function to perform A/B testing.

Sample Code

// cookie name
const COOKIE_NAME = 'ABTest';

// cookie value
const VALUE_A = 'index-a.html';
const VALUE_B = 'index-b.html';

// Root path, the origin must exist this path, and under this path, there are files index-a.html and index-b.html.
const BASE_PATH = '/abtest';

async function handleRequest(request) {
const urlInfo = new URL(request.url);

// Judge the URL path, if accessing non-abtest resources, directly responded.
if (!urlInfo.pathname.startsWith(BASE_PATH)) {
return fetch(request);
}

// Collected the current request's Cookie.
const cookies = new Cookies(request.headers.get('cookie'));
const abTestCookie = cookies.get(COOKIE_NAME);
const cookieValue = abTestCookie?.value;

// If the Cookie value is A test, Return index-a.html.
if (cookieValue === VALUE_A) {
urlInfo.pathname = `/${BASE_PATH}/${cookieValue}`;
return fetch(urlInfo.toString());
}

// If the Cookie value is B test, Return index-b.html.
if (cookieValue === VALUE_B) {
urlInfo.pathname = `/${BASE_PATH}/${cookieValue}`;
return fetch(urlInfo.toString());
}

// If the Cookie information does not exist, randomly grant the current request to A or B test.
const testValue = Math.random() < 0.5 ? VALUE_A : VALUE_B;
urlInfo.pathname = `/${BASE_PATH}/${testValue}`;

const response = await fetch(urlInfo.toString());

cookies.set(COOKIE_NAME, testValue, { path: '/', max_age: 60 });
response.headers.set('Set-Cookie', getSetCookie(cookies.get(COOKIE_NAME)));
return response;
}

// Concatenate Set-Cookie.
function getSetCookie(cookie) {
const cookieArr = [
`${encodeURIComponent(cookie.name)}=${encodeURIComponent(cookie.value)}`,
];

const key2name = {
expires: 'Expires',
max_age: 'Max-Age',
domain: 'Domain',
path: 'Path',
secure: 'Secure',
httponly: 'HttpOnly',
samesite: 'SameSite',
};

Object.keys(key2name).forEach(key => {
if (cookie[key]) {
cookieArr.push(`${key2name[key]}=${cookie[key]}`);
}
});

return cookieArr.join('; ');
}

addEventListener('fetch', event => {
event.respondWith(handleRequest(event.request));
});

Sample Preview

In the address bar of the browser, enter a URL that matches a trigger rule of the edge function to preview the effect of the sample code.




References