don't ever send empty pendings, instead grab the children

Author: yaacovCR

src/execution/IncrementalPublisher.ts

@@ -306,8 +306,8 @@ export class IncrementalPublisher {
       if (child.filtered) {
         continue;
       }
-      const maybePendingSource = this._publish(child);
-      if (maybePendingSource) {
+      const maybePendingSources = this._publish(child);
+      for (const maybePendingSource of maybePendingSources) {
         pendingSources.add(maybePendingSource);
       }
     }
@@ -537,8 +537,8 @@ export class IncrementalPublisher {
         if (child.filtered) {
           continue;
         }
-        const maybePendingSource = this._publish(child);
-        if (maybePendingSource) {
+        const maybePendingSources = this._publish(child);
+        for (const maybePendingSource of maybePendingSources) {
           newPendingSources.add(maybePendingSource);
         }
       }
@@ -649,7 +649,7 @@ export class IncrementalPublisher {
 
   private _publish(
     subsequentResultRecord: SubsequentResultRecord,
-  ): DeferredFragmentRecord | StreamRecord | undefined {
+  ): ReadonlyArray<DeferredFragmentRecord | StreamRecord> {
     if (isStreamItemsRecord(subsequentResultRecord)) {
       if (subsequentResultRecord.isCompleted) {
         this._push(subsequentResultRecord);
@@ -659,25 +659,31 @@ export class IncrementalPublisher {
 
       const stream = subsequentResultRecord.streamRecord;
       if (!stream.pendingSent) {
-        return stream;
+        return [stream];
       }
-      return;
+      return [];
     }
 
     if (subsequentResultRecord._pending.size > 0) {
       this._introduce(subsequentResultRecord);
     } else if (
-      subsequentResultRecord.deferredGroupedFieldSetRecords.size > 0 ||
-      subsequentResultRecord.children.size > 0
+      subsequentResultRecord.deferredGroupedFieldSetRecords.size === 0
     ) {
-      this._push(subsequentResultRecord);
+      const newPendingSources = [];
+      for (const child of subsequentResultRecord.children) {
+        const maybeNewPendingSources = this._publish(child);
+        newPendingSources.push(...maybeNewPendingSources);
+      }
+      return newPendingSources;
     } else {
-      return;
+      this._push(subsequentResultRecord);
     }
 
     if (!subsequentResultRecord.pendingSent) {
-      return subsequentResultRecord;
+      return [subsequentResultRecord];
     }
+
+    return [];
   }
 
   private _getChildren(

src/execution/__tests__/defer-test.ts

@@ -1077,34 +1077,27 @@ describe('Execute: defer directive', () => {
           },
         },
         pending: [
-          { id: '0', path: ['hero'] },
+          { id: '0', path: ['hero', 'nestedObject', 'deeperObject'] },
           { id: '1', path: ['hero', 'nestedObject', 'deeperObject'] },
         ],
         hasNext: true,
       },
       {
-        pending: [{ id: '2', path: ['hero', 'nestedObject', 'deeperObject'] }],
         incremental: [
           {
             data: {
               foo: 'foo',
             },
             id: '1',
           },
-        ],
-        completed: [{ id: '0' }, { id: '1' }],
-        hasNext: true,
-      },
-      {
-        incremental: [
           {
             data: {
               bar: 'bar',
             },
-            id: '2',
+            id: '0',
           },
         ],
-        completed: [{ id: '2' }],
+        completed: [{ id: '1' }, { id: '0' }],
         hasNext: false,
       },
     ]);