Add functions examples section

Author: Ekwuno

content/pages/platform/functions/9_migrating-from-workers.md renamed to content/pages/platform/functions/10_migrating-from-workers.md

@@ -1,7 +1,7 @@
 ---
 pcx-content-type: how-to
 title: Pricing and limits
-weight: 10
+weight: 11
 ---
 
 # Pricing and limits

content/pages/platform/functions/10_pricing-and-limits.md renamed to content/pages/platform/functions/11_pricing-and-limits.md

@@ -0,0 +1,13 @@
+---
+type: overview
+hideChildren: true
+pcx-content-type: navigation
+title: Functions examples
+weight: 8
+layout: list
+---
+
+# Functions examples
+
+
+{{<directory-listing>}}

content/pages/platform/functions/8_Function examples/_index.md

@@ -0,0 +1,53 @@
+---
+type: example
+summary: Set up an A/B test by controlling what page is served based on
+  cookies. This version supports passing the request through to test and control
+  on the origin.
+tags:
+  - Originless
+pcx-content-type: configuration
+title: A/B testing with middleware
+weight: 1001
+layout: example
+---
+
+```js
+---
+filename: /functions/_middleware.js
+---
+const cookieName = "ab-test-cookie"
+const newHomepagePathName = "/test"
+
+const abTest = async ({ request, next, env }) => {
+  const url = new URL(request.url)
+  // if homepage
+  if (url.pathname === "/") {
+    // if cookie ab-test-cookie=new then change the request to go to /test
+    // if no cookie set, pass x% of traffic and set a cookie value to "current" or "new"
+
+    let cookie = request.headers.get("cookie")
+    // is cookie set?
+    if (cookie && cookie.includes(`${cookieName}=new`)) {
+      // pass the request to /test
+      url.pathname = newHomepagePathName
+      return env.ASSETS.fetch(url)
+    } else {
+      const percentage = Math.floor(Math.random() * 100)
+      let version = "current" // default version
+      // change pathname and version name for 50% of traffic 
+      if (percentage < 50) {
+        url.pathname = newHomepagePathName
+        version = "new"
+      }
+      // get the static file from ASSETS, and attach a cookie
+      const asset = await env.ASSETS.fetch(url)
+      let response = new Response(asset.body, asset)
+      response.headers.append("Set-Cookie", `${cookieName}=${version}; path=/`)
+      return response
+    }
+  }
+  return next()
+};
+
+export const onRequest = [abTest];
+```

content/pages/platform/functions/8_Function examples/ab-testing.md

@@ -1,7 +1,7 @@
 ---
 pcx-content-type: how-to
 title: Advanced Mode
-weight: 8
+weight: 9
 ---
 
 # Advanced mode