fix(core): update

ts/00_commitinfo_data.ts

@@ -3,6 +3,6 @@
  */
 export const commitinfo = {
   name: '@push.rocks/smartstream',
-  version: '3.0.17',
+  version: '3.0.18',
   description: 'simplifies access to node streams'
 }

ts/smartstream.classes.smartduplex.ts

@@ -130,6 +130,9 @@ export class SmartDuplex<TInput = any, TOutput = any> extends Duplex {
   }
 
   public notBackpressured = true;
+  public get backpressured(): boolean {
+    return !this.notBackpressured;
+  }
   public push(chunkArg?: TOutput | null): boolean {
     const result = super.push(chunkArg);
     if (!result && this.handleBackpressure) {
@@ -161,9 +164,17 @@ export class SmartDuplex<TInput = any, TOutput = any> extends Duplex {
     try {
       const modifiedChunk = await this.writeFunction(chunk, tools);
       if (modifiedChunk) {
-        this.push(modifiedChunk);
+        this.push(modifiedChunk)
+        if (this.backpressured && this.handleBackpressure) {
+          this.once('drain', () => {
+            callback();
+          });
+        } else {
+          callback();
+        }      
+      } else {
+        callback();
       }
-      callback();
     } catch (err) {
       callback(err);
     }