chore: addressed comments

Author: lwin-kyaw

packages/shield-controller/src/backend.ts

@@ -1,4 +1,8 @@
-import { ConstantBackoff, HttpError } from '@metamask/controller-utils';
+import {
+  ConstantBackoff,
+  DEFAULT_MAX_RETRIES,
+  HttpError,
+} from '@metamask/controller-utils';
 import {
   EthMethod,
   SignatureRequestType,
@@ -333,7 +337,12 @@ function computePollingIntervalAndRetryCount(
   pollInterval: number,
 ) {
   const backoff = new ConstantBackoff(pollInterval);
-  const maxRetries = Math.floor(timeout / pollInterval) + 1;
+  const computedMaxRetries = Math.floor(timeout / pollInterval) + 1;
+
+  const maxRetries = isNaN(computedMaxRetries)
+    ? DEFAULT_MAX_RETRIES
+    : computedMaxRetries;
+
   return {
     backoff,
     maxRetries,

packages/shield-controller/src/polling-with-policy.test.ts

@@ -86,7 +86,8 @@ describe('PollingWithCockatielPolicy', () => {
             if (abortSignal.aborted) {
               reject(new Error('test error'));
             }
-            reject(new Error('test error'));
+            // eslint-disable-next-line @typescript-eslint/prefer-promise-reject-errors -- HttpError is a valid error which extends Error class
+            reject(new HttpError(412, 'Results are not available yet'));
           }, 100);
         });
       });