test: guard fetchProfile against null ctx.prev.result (CodeRabbit)

Author: sid88in

examples/pipeline-resolver-with-code/functions/fetchProfile.js

@@ -1,12 +1,20 @@
-import { util } from '@aws-appsync/utils';
+import { util, runtime } from '@aws-appsync/utils';
 
 export function request(ctx) {
+  // fetchUser returns null when the user isn't found; short-circuit the
+  // pipeline function instead of dereferencing a null result.
+  if (ctx.prev.result == null) {
+    runtime.earlyReturn(null);
+  }
   return {
     operation: 'GetItem',
     key: util.dynamodb.toMapValues({ userId: ctx.prev.result.id }),
   };
 }
 
 export function response(ctx) {
+  if (ctx.prev.result == null) {
+    return null;
+  }
   return { ...ctx.prev.result, profile: ctx.result };
 }