refactor(app): improve loading state management in user fetch

src/app/app.component.ts

@@ -27,16 +27,18 @@ export class AppComponent {
   ngOnInit() {
     this.userService.getUsers().subscribe(users => {
       this.users.set(users);
+      this.isLoadingUsers.set(false)
     });
   }
   
-  onUserSelect(event: Event) {
-    this.isLoadingTodos.set(true)
+  onUserSelect(event: Event): void {
     const userId = Number((event.target as HTMLSelectElement).value);
     this.selectedUserId.set(userId);
-    this.userService.getTodos(userId).subscribe(todos => {
-      this.todos.set(todos)
-      this.isLoadingTodos.set(false)
+    this.isLoadingTodos.set(true);
+    this.userService.getTodos(userId).subscribe({
+      next: (todos) => this.todos.set(todos),
+      error: () => this.isLoadingTodos.set(false),
+      complete: () => this.isLoadingTodos.set(false)
     });
   }
 }

src/app/user.service.ts

@@ -1,6 +1,6 @@
 import { Injectable } from '@angular/core';
 import { HttpClient } from '@angular/common/http';
-import { delay, Observable, shareReplay } from 'rxjs';
+import { delay, Observable } from 'rxjs';
 
 @Injectable({
   providedIn: 'root'