avoid multiple subscription when port changes after upload

Author: Alberto Iannaccone

demo/app.jsx

@@ -190,11 +190,15 @@ class App extends React.Component {
     };
 
     this.setState({ uploadingPort: target.port });
-    daemon.uploadingPortChanged.subscribe(newPort => this.setState({ uploadingPort: newPort }));
+    daemon.boardPortAfterUpload.subscribe(portStatus => {
+      if (portStatus.hasChanged) {
+        this.setState({ uploadingPort: portStatus.newPort });
+      }
+    });
 
     // Upload a compiled sketch.
     daemon.uploadSerial(target, 'serial_mirror', { bin: HEX });
-  };
+  }
 
   render() {
     const listSerialDevices = this.state.serialDevices.map((device, i) => <li key={i}>

src/daemon.js

@@ -19,7 +19,7 @@
 */
 
 import {
-  Subject, BehaviorSubject, interval, timer, UnsubscriptionError
+  Subject, BehaviorSubject, interval, timer
 } from 'rxjs';
 import {
   takeUntil, filter, startWith, first, distinctUntilChanged
@@ -80,7 +80,7 @@ export default class Daemon {
       .pipe(first())
       .pipe(takeUntil(this.downloadingDone));
 
-    this.uploadingPortChanged = new Subject();
+    this.boardPortAfterUpload = new Subject().pipe(first());
     this.uploadingPort = null;
   }
 
@@ -152,17 +152,23 @@ export default class Daemon {
               boardFound = currentSerialDevices.find(d => this.serialDevicesBeforeUpload.every(e => e.Name !== d.Name));
               if (boardFound) {
                 this.uploadingPort = boardFound.Name;
-                this.uploadingPortChanged.next(this.uploadingPort)
+                this.boardPortAfterUpload.next({
+                  hasChanged: true,
+                  newPort: this.uploadingPort
+                })
               }
             }
 
             if (boardFound) {
               this.waitingForPortToComeUp.unsubscribe();
               this.uploadingPort = null;
               this.serialDevicesBeforeUpload = null;
+              this.boardPortAfterUpload.next({
+                hasChanged: false
+              })
             }
           })
-        })
+        });
         this._upload(uploadPayload, uploadCommandInfo);
       });
   }