add crypto usage to example

Author: beeequeue

example/README.md

@@ -2,7 +2,10 @@
 
 This example shows a set up where a TypeScript function is build and deployed to CloudFront Functions via Terraform!
 
-The function does one thing: if the path starts with `/foo*` it will redirect it to `/bar*`.
+The function does two things:
+
+- Adds a md5 hash of the path as a query parameter
+- If the path starts with `/foo*` it will redirect it to `/bar*`
 
 This can be tested by visiting the URL below and seeing the path change from `/foo/nebula.webp` to `/bar/nebula.webp`!
 

example/src/handler.ts

@@ -1,3 +1,5 @@
+import crypto from "crypto"
+
 import type { CloudFrontFunctionsEvent } from "aws-lambda"
 
 type Response = CloudFrontFunctionsEvent["request"] | CloudFrontFunctionsEvent["response"]
@@ -17,14 +19,21 @@ var redirects: Redirect[] = [
 function handler(event: CloudFrontFunctionsEvent): Response {
   var request = event.request
 
+  var hasher = crypto.createHash("sha1")
+  hasher.update(request.uri)
+
   var match = redirects.find((redirect) => redirect.from.test(request.uri))
   if (match) {
     return {
       statusCode: 302,
       statusDescription: "Found",
       cookies: {},
       headers: {
-        location: { value: request.uri.replace(match.from, match.to) },
+        location: {
+          value: `${request.uri.replace(match.from, match.to)}?hash=${hasher.digest(
+            "hex",
+          )}`,
+        },
       },
     }
   }

example/tsconfig.json

@@ -21,7 +21,7 @@
 
     // Extra types
     "lib": ["es2020", "es2021"],
-    "types": []
+    "types": ["node"]
   },
 
   "include": ["src/**/*.ts"]

package.json

@@ -30,7 +30,7 @@
   "scripts": {
     "dev": "tsup --watch",
     "build": "tsup",
-    "lint": "eslint src",
+    "lint": "eslint src example/src",
     "test": "vitest run",
     "test:dev": "vitest",
     "typecheck": "tsc --noEmit --project tsconfig.json",