fix(lambda-at-edge): await external API rewrite (#1232)

Author: dphang

.eslintrc.js

@@ -39,6 +39,7 @@ module.exports = {
       ],
       plugins: ["promise"],
       rules: {
+        "require-await": "error",
         "promise/catch-or-return": "error"
       }
     },

packages/libs/lambda-at-edge/src/api-handler.ts

@@ -32,7 +32,7 @@ export const handler = async (
 
   if (external) {
     const { path } = external;
-    createExternalRewriteResponse(path, req, res, request.body?.data);
+    await createExternalRewriteResponse(path, req, res, request.body?.data);
   }
 
   const response = await responsePromise;