fix: properly handle _processing flag

Author: pathurs

source/processors/complex-processor.ts

@@ -59,10 +59,14 @@ export abstract class ComplexProcessor<TData> extends Subject<TData> implements
         this.lastInput = data;
 
         if (!this.shouldProcess(force)) {
-            return data;
+            return this.lastOutput;
         }
+        
+        this._processing = true;
 
         const processedData = this.processor(data);
+        
+        this._processing = false;
 
         return this.next(processedData);
     }

source/processors/queue-processor.ts

@@ -113,14 +113,10 @@ export class QueueProcessor<TData> extends ComplexProcessor<TData> {
         this.lastInput = data;
         let processedData = data;
 
-        this._processing = true;
-
         this.processorTuples.forEach(processorTuple => {
             processedData = this.runProcessor(processedData, processorTuple[0]);
         });
 
-        this._processing = false;
-
         return processedData;
     }