start of message service

src/app/services/message.service.spec.ts

@@ -0,0 +1,16 @@
+import { TestBed } from '@angular/core/testing';
+
+import { MessageService } from './message.service';
+
+describe('MessageService', () => {
+  let service: MessageService;
+
+  beforeEach(() => {
+    TestBed.configureTestingModule({});
+    service = TestBed.inject(MessageService);
+  });
+
+  it('should be created', () => {
+    expect(service).toBeTruthy();
+  });
+});

src/app/services/message.service.ts

@@ -0,0 +1,14 @@
+import { Injectable } from '@angular/core';
+
+@Injectable()
+export class MessageService {
+  messages: string[] = [];
+
+  add(message: string) {
+    this.messages.push(message);
+  }
+
+  clear() {
+    this.messages = [];
+  }
+}