Add examples for static routing

Author: korinne

src/content/docs/workers/static-assets/routing/worker-script.mdx

@@ -48,6 +48,36 @@ If you need to always run your Worker script before serving static assets (for e
 
 </WranglerConfig>
 
+<TypeScriptExample filename="./worker/index.ts">
+
+```ts
+import { WorkerEntrypoint } from "cloudflare:workers";
+
+export default class extends WorkerEntrypoint<Env> {
+	async fetch(request: Request) {
+		// You can perform checks before fetching assets
+		const user = await checkIfRequestIsAuthenticated(request);
+
+		if (!user) {
+			return new Response("Unauthorized", { status: 401 });
+		}
+
+		// You can then just fetch the assets as normal, or you could pass in a custom Request object here if you wanted to fetch some other specific asset
+		const assetResponse = await this.env.ASSETS.fetch(request);
+
+		// You can return static asset response as-is, or you can transform them with something like HTMLRewriter
+		return new HTMLRewriter()
+			.on("#user", {
+				element(element) {
+					element.setInnerContent(JSON.stringify({ name: user.name }));
+				},
+			})
+			.transform(assetResponse);
+	}
+}
+```
+</TypeScriptExample>
+
 ### Run Worker first for selective paths
 
 You can also configure selective Worker-first routing using an array of route patterns, often paired with the [`single-page-application` setting](/workers/static-assets/routing/single-page-application/#advanced-routing-control). This allows you to run the Worker first only for specific routes while letting other requests follow the default asset-first behavior:
@@ -63,9 +93,37 @@ You can also configure selective Worker-first routing using an array of route pa
 		"directory": "./dist/",
 		"not_found_handling": "single-page-application",
 		"binding": "ASSETS",
-		"run_worker_first": ["/api/*", "!/api/docs/*"]
+		"run_worker_first": ["/oauth/callback"]
 	}
 }
 ```
 
 </WranglerConfig>
+
+<TypeScriptExample filename="./worker/index.ts">
+
+```ts
+import { WorkerEntrypoint } from "cloudflare:workers";
+
+export default class extends WorkerEntrypoint<Env> {
+	async fetch(request: Request) {
+		// The only thing this Worker script does is handle an OAuth callback.
+		// All other requests either serve an asset that matches or serve the index.html fallback, without ever hitting this code.
+		const url = new URL(request.url);
+		const code = url.searchParams.get("code");
+		const state = url.searchParams.get("state");
+
+		const accessToken = await exchangeCodeForToken(code, state);
+		const sessionIdentifier = await storeTokenAndGenerateSession(accessToken);
+
+		// Redirect back to the index, but set a cookie that the front-end will use.
+		return new Response(null, {
+			headers: {
+				"Location": "/",
+				"Set-Cookie": `session_token=${sessionIdentifier}; HttpOnly; Secure; SameSite=Lax; Path=/`
+			}
+		});
+	}
+}
+```
+</TypeScriptExample>