feat: add notifier service

src/app/services/notifier.spec.ts

@@ -0,0 +1,27 @@
+import { fakeAsync, TestBed, tick } from '@angular/core/testing';
+
+import { Notifier } from './notifier';
+import { Notification } from '../models/Notification';
+
+describe('Notifier', () => {
+  let service: Notifier;
+
+  beforeEach(() => {
+    TestBed.configureTestingModule({});
+    service = TestBed.inject(Notifier);
+  });
+
+  it('should be created', () => {
+    expect(service).toBeTruthy();
+  });
+
+  it('should set notification on notify and clean it after 800ms', fakeAsync(() => {
+    TestBed.tick();
+    const NOTIFICATION_MOCK = new Notification('MOCK NOTIFICATION');
+    service.notify(NOTIFICATION_MOCK);
+    expect(service.notification$()).toEqual(NOTIFICATION_MOCK);
+    TestBed.tick();
+    tick(1000);
+    expect(service.notification$()).toEqual(null);
+  }));
+});

src/app/services/notifier.ts

@@ -0,0 +1,25 @@
+import { effect, Injectable, signal } from '@angular/core';
+import { Notification } from '../models/Notification';
+@Injectable({
+  providedIn: 'root',
+})
+export class Notifier {
+  private readonly notification = signal<Notification | null>(null);
+  readonly notification$ = this.notification.asReadonly();
+  constructor() {
+    effect(() => {
+      if (this.notification$()) {
+        setTimeout(() => {
+          this.cleanup();
+        }, 800);
+      }
+    });
+  }
+  notify(notification: Notification) {
+    this.notification.set(notification);
+  }
+
+  private cleanup() {
+    this.notification.set(null);
+  }
+}