krejko

import { Injectable } from '@angular/core';

@Injectable()
export class LoginService {

  constructor() { }

  testUser = {username: 'tester', password: 'password'};
  loggedIn = false;

krejko

import { LoginService } from './login.service';

export class ViewComponent implements OnInit {

  constructor(private loginService: LoginService) {}

  ngOnInit() {
    if (this.loginService.login('tester', 'password')) {
      console.log('Logged In');
    } else {

krejko

// Other imports removed for brevity
import { LoginService } from './login.service';

@NgModule({
  ...
  providers: [LoginService],
  ...
})

krejko

import { TestBed, inject } from '@angular/core/testing';

import { LoginService } from './login.service';

describe('LoginService', () => {
  beforeEach(() => {
    TestBed.configureTestingModule({
      providers: [LoginService]
    });
  });

krejko

import { Injectable } from '@angular/core';

@Injectable()
export class LoginService {

  constructor() { }

}