feat: add tests for rerender component

Author: shanmukhateja

demo/src/app/advanced/rerender.component.spec.ts

@@ -0,0 +1,70 @@
+/* tslint:disable:no-unused-variable */
+
+import { RouterTestingModule } from '@angular/router/testing';
+import { HttpClientModule } from '@angular/common/http';
+import { NO_ERRORS_SCHEMA, SecurityContext } from '@angular/core';
+import { ComponentFixture, TestBed, waitForAsync } from '@angular/core/testing';
+import { DataTableDirective, DataTablesModule } from 'angular-datatables';
+import { MarkdownModule } from 'ngx-markdown';
+import { BaseDemoComponent } from '../base-demo/base-demo.component';
+import { AppRoutingModule } from '../app.routing';
+import { FormsModule } from '@angular/forms';
+import { RerenderComponent } from './rerender.component';
+
+
+let fixture: ComponentFixture<RerenderComponent>, component: RerenderComponent = null;
+
+describe('RerenderComponent', () => {
+  beforeEach(() => {
+    fixture = TestBed.configureTestingModule({
+      declarations: [
+        BaseDemoComponent,
+        RerenderComponent,
+        DataTableDirective
+      ],
+      imports: [
+        AppRoutingModule,
+        RouterTestingModule,
+        DataTablesModule.forRoot(),
+        HttpClientModule,
+        MarkdownModule.forRoot(
+          {
+            sanitize: SecurityContext.NONE
+          }
+        ),
+        FormsModule
+      ],
+      schemas: [NO_ERRORS_SCHEMA]
+    }).createComponent(RerenderComponent);
+
+    component = fixture.componentInstance;
+
+    fixture.detectChanges(); // initial binding
+  });
+
+  it('should create the app', waitForAsync(() => {
+    const app = fixture.debugElement.componentInstance;
+    expect(app).toBeTruthy();
+  }));
+
+  it('should have title "Rerender"', waitForAsync(() => {
+    const app = fixture.debugElement.componentInstance as RerenderComponent;
+    expect(app.pageTitle).toBe('Rerender');
+  }));
+
+  it('should recreate table when Rerender is clicked', async () => {
+    const app = fixture.componentInstance as RerenderComponent;
+    await fixture.whenStable();
+
+    const rerenderSpy = spyOn(app, 'rerender' as any);
+
+    const triggerBtns: HTMLButtonElement[] = Array.from(fixture.nativeElement.querySelectorAll('button'));
+    const triggerBtn: HTMLButtonElement = triggerBtns.find(e => e.textContent.includes('Rerender'));
+
+    triggerBtn.click();
+    triggerBtn.dispatchEvent(new Event('click'));
+
+    expect(rerenderSpy).toHaveBeenCalled();
+  });
+
+});