refactor: remove some duplicated code

routes/api/tmdb/[id].ts

@@ -1,6 +1,7 @@
-import { HandlerContext } from "$fresh/server.ts";
+import { HandlerContext, Handlers } from "$fresh/server.ts";
 import { getMovie } from "@lib/tmdb.ts";
 import * as cache from "@lib/cache/cache.ts";
+import { json } from "@lib/helpers.ts";
 
 type CachedMovieCredits = {
   lastUpdated: number;
@@ -9,7 +10,7 @@ type CachedMovieCredits = {
 
 const CACHE_INTERVAL = 1000 * 60 * 24 * 30;
 
-export const handler = async (
+const GET = async (
   _req: Request,
   _ctx: HandlerContext,
 ) => {
@@ -21,16 +22,13 @@ export const handler = async (
     });
   }
 
-  const headers = new Headers();
-  headers.append("Content-Type", "application/json");
-
   const cacheId = `/movie/${id}`;
 
   const cachedResponse = await cache.get<CachedMovieCredits>(cacheId);
   if (
     cachedResponse && Date.now() < (cachedResponse.lastUpdated + CACHE_INTERVAL)
   ) {
-    return new Response(JSON.stringify(cachedResponse.data), { headers });
+    return json(cachedResponse.data);
   }
 
   const res = await getMovie(+id);
@@ -43,5 +41,9 @@ export const handler = async (
     }),
   );
 
-  return new Response(JSON.stringify(res));
+  return json(res);
+};
+
+export const handler: Handlers = {
+  GET,
 };