Add observer debugging using tap

src/app/user.service.ts

 import { Injectable } from '@angular/core';
 import { HttpClient, HttpErrorResponse } from '@angular/common/http';
+
 import { throwError as observableThrowError,  Observable, BehaviorSubject, of, EMPTY } from 'rxjs';
-import { map, catchError, combineLatest } from 'rxjs/operators';
+import { map, catchError, combineLatest, tap } from 'rxjs/operators';
 
 import { CookieService } from 'ngx-cookie-service';
 import { StompConfig, StompRService } from '@stomp/ng2-stompjs';
@@ -21,12 +22,15 @@ export class UserService {
   private initialized = false;
   private loggedIn = false;
 
+  private observerDebugging = false;
+
   // relogin on failed XHR calls
   // is turned off when the user is deactivated
   private autoReLogin = true;
 
   private user: User;
-  private user$: BehaviorSubject<User>;
+  private user$: BehaviorSubject<User> = new BehaviorSubject(undefined);
+  private userEmissions: number = 0;
 
   private sshKeys: Map<number, SSHKey> = new Map([]);
   private sshKeys$ = new BehaviorSubject<SSHKey[]>([]);
@@ -48,7 +52,6 @@ export class UserService {
     private stompService: StompRService,
     private prefs: PreferencesService,
   ) {
-    this.user$ = new BehaviorSubject(null);
     this.connect();
   }
 
@@ -58,8 +61,6 @@ export class UserService {
 
     this.userSrc().subscribe(
       (newUser: User) => {
-        console.log('user$:', newUser);
-
         if (newUser == undefined || newUser == null) {
           // LOGGED OUT
           // show the logout to the user
@@ -247,6 +248,14 @@ export class UserService {
     return observableThrowError(error);
   }
 
+  private tapLogger(name: string): (e: any) => void {
+    return e => {
+      if (this.observerDebugging) {
+        console.log(name, e);
+      }
+    }
+  }
+
   // PUBLIC API
   public login(idp?: IdP): void {
     if (idp) {
@@ -343,23 +352,34 @@ export class UserService {
   // DATA SERVICE API
   //
   public subscribeSpecific<T>(selector: (user: User) => T): Observable<T> {
-    return this.userSrc().pipe(map(selector));
+    return this.userSrc().pipe(
+      map(selector),
+      tap(this.tapLogger('subscribeSpecific')),
+    );
   }
 
   public sshKeysSrc(): Observable<SSHKey[]> {
-    return this.sshKeys$.asObservable();
+    return this.sshKeys$.asObservable().pipe(
+      tap(this.tapLogger('sshKeysSrc')),
+    );
   }
 
   public userSrc(): Observable<User> {
-    return this.user$.asObservable();
+    return this.user$.asObservable().pipe(
+      tap(this.tapLogger('userSrc')),
+    );
   }
 
   public deploymentsSrc(): Observable<Deployment[]> {
-    return this.deployments$.asObservable();
+    return this.deployments$.asObservable().pipe(
+      tap(this.tapLogger('deploymentsSrc')),
+    );
   }
 
   public depStatesSrc(): Observable<DeploymentState[]> {
-    return this.deploymentStates$.asObservable();
+    return this.deploymentStates$.asObservable().pipe(
+      tap(this.tapLogger('depStatesSrc')),
+    );
   }
 
   public subscribeStateFor(service: Service): Observable<DeploymentState> {
@@ -367,6 +387,7 @@ export class UserService {
       map((states: DeploymentState[]) => states.find(
           (dsi: DeploymentState) => dsi.service.id == service.id,
       )),
+      tap(this.tapLogger('subscribeStateFor')),
     );
   }
 
@@ -378,11 +399,14 @@ export class UserService {
           );
         }
       ),
+      tap(this.tapLogger('subscribeDeployment')),
     );
   }
 
   public servicesSrc(): Observable<Service[]> {
-    return this.subscribeSpecific(this.serviceSelector);
+    return this.subscribeSpecific(this.serviceSelector).pipe(
+      tap(this.tapLogger('servicesSrc')),
+    );
   }
 
   public vosSrc(): Observable<VO[]> {
@@ -406,7 +430,7 @@ export class UserService {
 
           return vos;
         }
-      )
+      ),
     );
   }
 }