manivelarjunan

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

@Injectable()
export class UserService {
  user = {
    name: 'Mannie'
  };

  getUser() {
    return this.user;

manivelarjunan

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

import { UserComponent } from './user.component';
import { UserService } from './user.service';

describe('UserComponent', () => {

  beforeEach(async(() => {
    TestBed.configureTestingModule({
      declarations: [UserComponent]

manivelarjunan

<p *ngIf="systemError">{{systemErrorMessage}}</p>
<div *ngIf="isLoggedIn && !systemError">
  <p>
    {{userDetail.name}}
  </p>
  <p>Note: Above user details returned by async call.</p>
</div>

<div *ngIf="!isLoggedIn && !systemError">
  <p>

manivelarjunan

import { Component, OnInit } from '@angular/core';
import { UserAsyncService } from './user-async.service';
import { Observable } from 'rxjs';

@Component({
  selector: 'app-user-async',
  templateUrl: './user-async.component.html',
  styleUrls: ['./user-async.component.scss'],
  providers: [UserAsyncService]
})

manivelarjunan

import { TestBed, tick, fakeAsync } from '@angular/core/testing';
import { UserAsyncComponent } from './user-async.component';
import { UserAsyncService } from './user-async.service';
import { Observable, Observer } from 'rxjs';

describe('User Async Component:', () => {
  beforeEach(async () => {
    TestBed.configureTestingModule({
      declarations: [UserAsyncComponent]
    });

manivelarjunan

import { Observable, Observer } from 'rxjs';

export class UserAsyncService {
  user = { name: 'Mannie' };
  getUserDetails() {
    // Create an observables.
    const userObservables = Observable.create(
      (observer: Observer<{ name: string }>) => {
        setTimeout(() => {
          observer.next(this.user);

manivelarjunan

import { Pipe, PipeTransform } from '@angular/core';

@Pipe({
  name: 'reversePipe'
})
export class ReversePipe implements PipeTransform {
  transform(value: any, args?: any): any {
    return value
      .split('')
      .reverse()

manivelarjunan

import { ReversePipe } from './reverse-value.pipe';

// Isolated test case.
describe('ReversePipe', () => {
  it('create an instance', () => {
    const pipe = new ReversePipe();
    expect(pipe).toBeTruthy();
    expect(pipe.transform('olleh')).toBe('hello');
  });
});

manivelarjunan

export interface GoogleData {
  id: number;
  country: string;
  zipCode: string;
}

manivelarjunan

import React, { useState } from 'react';
import Person from './Person/Person';
import './App.css';

//class App extends Component {
  const app = props => {
  const [personsState,setPersonState] =  useState({
    persons: [
      {name:'mani',age:45},
      {name:'papi',age:34}