ng2 testing Unit test when a button is enabled using Karma in Angular2 http://stackoverflow.com/questions/41544323/unit-test-when-a-button-is-enabled-using-karma-in-angular2

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<!DOCTYPE html>
<html>

  <head>
    <script>
      document.write('<base href="' + document.location + '" />');

    </script>
    <title>Sample App Specs</title>
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    <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/jasmine/2.4.1/jasmine.css">
  </head>

  <body>
    <script src="https://unpkg.com/systemjs@0.19.39/dist/system.src.js"></script>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/jasmine/2.4.1/jasmine.js"></script>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/jasmine/2.4.1/jasmine-html.js"></script>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/jasmine/2.4.1/boot.js"></script>
    <script src="https://unpkg.com/reflect-metadata@0.1.8"></script>
    <script src="https://unpkg.com/zone.js@0.6.25?main=browser"></script>
    <script src="https://unpkg.com/zone.js/dist/long-stack-trace-zone.js?main=browser"></script>
    <script src="https://unpkg.com/zone.js/dist/proxy.js?main=browser"></script>
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    <script src="https://unpkg.com/zone.js/dist/fake-async-test.js?main=browser"></script>
    <script>
      var __spec_files__ = [
        'app/login.component.spec'];

    </script>
    <script src="browser-test-shim.js"></script>
  </body>

</html>
<!-- Copyright 2016 Google Inc. All Rights Reserved.Use of this source code is governed by an MIT-style license thatcan be found in the LICENSE file at http://angular.io/license-->

// BROWSER TESTING SHIM
// Keep it in-sync with what karma-test-shim does
/*global jasmine, __karma__, window*/
(function () {

Error.stackTraceLimit = 0; // "No stacktrace"" is usually best for app testing.

// Uncomment to get full stacktrace output. Sometimes helpful, usually not.
// Error.stackTraceLimit = Infinity; //

jasmine.DEFAULT_TIMEOUT_INTERVAL = 3000;

var baseURL = document.baseURI;
baseURL = baseURL + baseURL[baseURL.length-1] ? '' : '/';

System.config({
  baseURL: baseURL,
  // Extend usual application package list with test folder
  packages: { 'testing': { main: 'index.js', defaultExtension: 'js' } },

  // Assume npm: is set in `paths` in systemjs.config
  // Map the angular testing umd bundles
  map: {
    '@angular/core/testing': 'npm:@angular/core/bundles/core-testing.umd.js',
    '@angular/common/testing': 'npm:@angular/common/bundles/common-testing.umd.js',
    '@angular/compiler/testing': 'npm:@angular/compiler/bundles/compiler-testing.umd.js',
    '@angular/platform-browser/testing': 'npm:@angular/platform-browser/bundles/platform-browser-testing.umd.js',
    '@angular/platform-browser-dynamic/testing': 'npm:@angular/platform-browser-dynamic/bundles/platform-browser-dynamic-testing.umd.js',
    '@angular/http/testing': 'npm:@angular/http/bundles/http-testing.umd.js',
    '@angular/router/testing': 'npm:@angular/router/bundles/router-testing.umd.js',
    '@angular/forms/testing': 'npm:@angular/forms/bundles/forms-testing.umd.js',
  },
});

System.import('systemjs.config.js')
  .then(initTestBed)
  .then(initTesting);

function initTestBed(){
  return Promise.all([
    System.import('@angular/core/testing'),
    System.import('@angular/platform-browser-dynamic/testing')
  ])

  .then(function (providers) {
    var coreTesting    = providers[0];
    var browserTesting = providers[1];

    coreTesting.TestBed.initTestEnvironment(
      browserTesting.BrowserDynamicTestingModule,
      browserTesting.platformBrowserDynamicTesting());
  })
}

// Import all spec files defined in the html (__spec_files__)
// and start Jasmine testrunner
function initTesting () {
  console.log('loading spec files: '+__spec_files__.join(', '));
  return Promise.all(
    __spec_files__.map(function(spec) {
      return System.import(spec);
    })
  )
  //  After all imports load,  re-execute `window.onload` which
  //  triggers the Jasmine test-runner start or explain what went wrong
  .then(success, console.error.bind(console));

  function success () {
    console.log('Spec files loaded; starting Jasmine testrunner');
    window.onload();
  }
}

})();


/*
Copyright 2016 Google Inc. All Rights Reserved.
Use of this source code is governed by an MIT-style license that
can be found in the LICENSE file at http://angular.io/license
*/

/**
 * WEB ANGULAR VERSION
 * (based on systemjs.config.js in angular.io)
 * System configuration for Angular samples
 * Adjust as necessary for your application needs.
 */
(function (global) {
  System.config({
    // DEMO ONLY! REAL CODE SHOULD NOT TRANSPILE IN THE BROWSER
    transpiler: 'ts',
    typescriptOptions: {
      // Copy of compiler options in standard tsconfig.json
      "target": "es5",
      "module": "commonjs",
      "moduleResolution": "node",
      "sourceMap": true,
      "emitDecoratorMetadata": true,
      "experimentalDecorators": true,
      "noImplicitAny": true,
      "suppressImplicitAnyIndexErrors": true
    },
    meta: {
      'typescript': {
        "exports": "ts"
      }
    },
    paths: {
      // paths serve as alias
      'npm:': 'https://unpkg.com/'
    },
    // map tells the System loader where to look for things
    map: {
      // our app is within the app folder
      app: 'app',

      // angular bundles
      '@angular/core': 'npm:@angular/core/bundles/core.umd.js',
      '@angular/common': 'npm:@angular/common/bundles/common.umd.js',
      '@angular/compiler': 'npm:@angular/compiler/bundles/compiler.umd.js',
      '@angular/platform-browser': 'npm:@angular/platform-browser/bundles/platform-browser.umd.js',
      '@angular/platform-browser-dynamic': 'npm:@angular/platform-browser-dynamic/bundles/platform-browser-dynamic.umd.js',
      '@angular/http': 'npm:@angular/http/bundles/http.umd.js',
      '@angular/router': 'npm:@angular/router/bundles/router.umd.js',
      '@angular/router/upgrade': 'npm:@angular/router/bundles/router-upgrade.umd.js',
      '@angular/forms': 'npm:@angular/forms/bundles/forms.umd.js',
      '@angular/upgrade': 'npm:@angular/upgrade/bundles/upgrade.umd.js',
      '@angular/upgrade/static': 'npm:@angular/upgrade/bundles/upgrade-static.umd.js',
      '@angular/material': 'npm:@angular/material/bundles/material.umd.js',
      
      // other libraries
      'rxjs':                      'npm:rxjs',
      'angular-in-memory-web-api': 'npm:angular-in-memory-web-api/bundles/in-memory-web-api.umd.js',
      'ts':                        'npm:plugin-typescript@4.0.10/lib/plugin.js',
      'typescript':                'npm:typescript@2.0.3/lib/typescript.js',

    },
    // packages tells the System loader how to load when no filename and/or no extension
    packages: {
      app: {
        main: './main.ts',
        defaultExtension: 'ts'
      },
      rxjs: {
        defaultExtension: 'js'
      }
    }
  });

  if (global.autoBootstrap) { bootstrap(); }

  // Bootstrap with a default `AppModule`
  // ignore an `app/app.module.ts` and `app/main.ts`, even if present
  // This function exists primarily (exclusively?) for the QuickStart
  function bootstrap() {
    console.log('Auto-bootstrapping');

    // Stub out `app/main.ts` so System.import('app') doesn't fail if called in the index.html
    System.set(System.normalizeSync('app/main.ts'), System.newModule({ }));

    // bootstrap and launch the app (equivalent to standard main.ts)
    Promise.all([
      System.import('@angular/platform-browser-dynamic'),
      getAppModule()
    ])
    .then(function (imports) {
      var platform = imports[0];
      var app      = imports[1];
      platform.platformBrowserDynamic().bootstrapModule(app.AppModule);
    })
    .catch(function(err){ console.error(err); });
  }

  // Make the default AppModule
  // returns a promise for the AppModule
  function getAppModule() {
    console.log('Making a bare-bones, default AppModule');

    return Promise.all([
      System.import('@angular/core'),
      System.import('@angular/platform-browser'),
      System.import('app/app.component')
    ])
    .then(function (imports) {

      var core    = imports[0];
      var browser = imports[1];
      var appComp = imports[2].AppComponent;

      var AppModule = function() {}

      AppModule.annotations = [
        new core.NgModule({
          imports:      [ browser.BrowserModule ],
          declarations: [ appComp ],
          bootstrap:    [ appComp ]
        })
      ]
      return {AppModule: AppModule};
    })
  }
})(this);

/*
Copyright 2016 Google Inc. All Rights Reserved.
Use of this source code is governed by an MIT-style license that
can be found in the LICENSE file at http://angular.io/license
*/


/*
Copyright 2016 Google Inc. All Rights Reserved.
Use of this source code is governed by an MIT-style license that
can be found in the LICENSE file at http://angular.io/license
*/

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

@Component({
  selector: 'my-app',
  template: `
   <form (ngSubmit)="login()" #loginForm="ngForm">

        <md-input-container class="md-block">
            <input md-input [(ngModel)]="user.email" class="userEmail"
                name="userEmail" type="email" placeholder="Email" 
                ngControl="userEmail" 
            required>
        </md-input-container>
        <br>

        <md-input-container class="md-block">
            <input md-input [(ngModel)]="user.password" class="userPassword"
                name="userPassword" type="password" placeholder="Password" 
                ngControl="userPassword" 
            required>
        </md-input-container>
        <br>

        <button  color="primary" md-button 
            type="submit" class='loginButton'
        [disabled]="!loginForm.form.valid">
            Login
         </button>
    </form>
  `
})
export class LoginComponent {
  user = {
    email: '',
    password: ''
  };

  login() {

  }
}

import { ComponentFixture, TestBed, async } from '@angular/core/testing';
import { By } from '@angular/platform-browser';

import { FormsModule } from '@angular/forms';

import { LoginComponent } from './login.component';
import { MaterialModule } from '@angular/material'


describe('LoginComponent (inline template)', () => {
  let comp: LoginComponent;
  let fixture: ComponentFixture<LoginComponent>;
  let userEmail: HTMLInputElement;
  let userPassword: HTMLInputElement;
  let loginBtn: HTMLButtonElement;

  beforeEach(() => {
    TestBed.configureTestingModule({
      declarations: [LoginComponent],
      imports: [MaterialModule.forRoot(), FormsModule]
    });

    fixture = TestBed.createComponent(LoginComponent);
    comp = fixture.componentInstance;

    userEmail = fixture.debugElement.query(By.css('.userEmail')).nativeElement;
    userPassword = fixture.debugElement.query(By.css('.userPassword')).nativeElement;
    loginBtn = fixture.debugElement.query(By.css('.loginButton')).nativeElement;
  });

  it('should check initial input', () => {
    fixture.detectChanges();
    expect(userEmail.value).toBe('')
  });

  it('should check later input', async(() => {
    fixture.detectChanges();
    fixture.whenStable().then(() => {
      userEmail.value = 'someValue';
      userEmail.dispatchEvent(new Event('change'));

      expect(userEmail.value).toBe('someValue');
    });

  }));
  
  //EDITED: NEW TEST
  it('should check loginBtn is disabled initially', async(() => {
    fixture.detectChanges();
    fixture.whenStable().then(() => {
      debugger;
      fixture.detectChanges();
      expect(loginBtn.disabled).toBe(true)
     })
  }));

  it('should check loginBtn is enabled after inputs check out', async(() => {
    fixture.detectChanges();
    fixture.whenStable().then(() => {
      userEmail.value = 'raj@gmail.com';
      userEmail.dispatchEvent(new Event('input'));

      userPassword.value = 'asdf';
      userPassword.dispatchEvent(new Event('input'));
      fixture.detectChanges();
      expect(loginBtn.disabled).toBe(false)
    });
  }));
});