add hasNext method

Author: yaacovCR

src/execution/execute.ts

@@ -350,7 +350,7 @@ function executeImpl(
         (data) => {
           const initialResult = buildResponse(data, exeContext.errors);
           const publisher = exeContext.publisher;
-          if (publisher.subsequentPayloads.size > 0) {
+          if (publisher.hasNext()) {
             return {
               initialResult: {
                 ...initialResult,
@@ -369,7 +369,7 @@ function executeImpl(
     }
     const initialResult = buildResponse(result, exeContext.errors);
     const publisher = exeContext.publisher;
-    if (publisher.subsequentPayloads.size > 0) {
+    if (publisher.hasNext()) {
       return {
         initialResult: {
           ...initialResult,

src/execution/publisher.ts

@@ -32,6 +32,10 @@ export class Publisher {
     this.subsequentPayloads.add(payload);
   }
 
+  hasNext(): boolean {
+    return this.subsequentPayloads.size > 0;
+  }
+
   filter(predicate: (payload: AsyncPayloadRecord) => boolean): void {
     this.subsequentPayloads.forEach((asyncRecord) => {
       if (predicate(asyncRecord)) {