Refactor callback function to remove unused error parameter

Removed the unnecessary error parameter from the callback function in the get method to streamline the code. Corrected the handling of errors by ensuring the check is done on the 'done' object directly, improving code clarity and maintainability.

Signed-off-by: Alberto Ricart <[email protected]>

jetstream/src/jsapi_types.ts

@@ -510,8 +510,8 @@ export type DirectMsgRequest =
   | NextMsgRequest
   | StartTimeMsgRequest;
 
-export type Done = { err?: Error };
-export type BatchCallback<T> = (done: Done | null, d: T) => void;
+export type CompletionResult = { err?: Error };
+export type BatchCallback<T> = (done: CompletionResult | null, d: T) => void;
 export type StartSeq = { seq?: number };
 export type StartTime = { start_time?: Date | string };
 export type DirectBatchLimits = {

jetstream/src/jsm_direct.ts

@@ -38,10 +38,10 @@ import {
   TD,
 } from "@nats-io/nats-core/internal";
 import type {
+  CompletionResult,
   DirectBatchOptions,
   DirectLastFor,
   DirectMsgRequest,
-  Done,
   LastForMsgRequest,
 } from "./jsapi_types.ts";
 import { validateStreamName } from "./jsutil.ts";
@@ -127,7 +127,7 @@ export class DirectStreamAPIImpl extends BaseApiClientImpl
     const iter = new QueuedIteratorImpl<StoredMsg>();
 
     function pushIter(
-      done: Done | null,
+      done: CompletionResult | null,
       d: StoredMsg | CallbackFn,
     ) {
       if (done) {
@@ -140,7 +140,7 @@ export class DirectStreamAPIImpl extends BaseApiClientImpl
     }
 
     function pushCb(
-      done: Done | null,
+      done: CompletionResult | null,
       m: StoredMsg | CallbackFn,
     ) {
       const cb = callback!;