docs: add forms overview example for snippets (#25663)

PR Close #25663

aio/content/examples/forms-overview/src/app/reactive/name/name.component.spec.ts

@@ -0,0 +1,62 @@
+// #docregion
+import { async, ComponentFixture, TestBed } from '@angular/core/testing';
+import { ReactiveFormsModule } from '@angular/forms';
+
+import { ReactiveNameComponent } from './name.component';
+import { createNewEvent } from '../../shared/utils';
+
+// #docregion tests
+describe('Reactive Name Component', () => {
+// #enddocregion tests
+  let component: ReactiveNameComponent;
+  let fixture: ComponentFixture<ReactiveNameComponent>;
+
+  beforeEach(async(() => {
+    TestBed.configureTestingModule({
+      imports: [ReactiveFormsModule],
+      declarations: [ReactiveNameComponent]
+    })
+    .compileComponents();
+  }));
+
+  beforeEach(() => {
+    fixture = TestBed.createComponent(ReactiveNameComponent);
+    component = fixture.componentInstance;
+    fixture.detectChanges();
+  });
+
+  it('should create', () => {
+    expect(component).toBeTruthy();
+  });
+
+// #docregion tests
+  it('should update the value in the control', () => {
+    // update the control value
+    component.name.setValue('Nancy');
+
+    // query the element
+    const input = fixture.nativeElement.querySelector('input');
+
+    // check its value
+    expect(input.value).toBe('Nancy');
+  });
+
+  it('should update the value of the input field', () => {
+    // update the control value
+    component.name.setValue('Nancy');
+
+    // query the element
+    const input = fixture.nativeElement.querySelector('input');
+    expect(input.value).toEqual('Nancy');
+
+    // update the form field value
+    input.value = 'Smith';
+
+    // Use utility function to create custom event, then dispatch on the input
+    const event = createNewEvent('input');
+    input.dispatchEvent(event);
+
+    expect(fixture.componentInstance.name.value).toEqual('Smith');
+  });
+});
+// #enddocregion

aio/content/examples/forms-overview/src/app/reactive/name/name.component.ts

@@ -0,0 +1,17 @@
+// #docplaster
+// #docregion
+import { Component } from '@angular/core';
+import { FormControl } from '@angular/forms';
+
+@Component({
+// #enddocregion
+  selector: 'app-reactive-name',
+// #docregion
+  template: `
+    Name: <input type="text" [formControl]="name">
+  `
+})
+export class ReactiveNameComponent {
+  name = new FormControl('');
+}
+// #enddocregion

aio/content/examples/forms-overview/src/app/reactive/reactive.module.spec.ts

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+import { ReactiveModule } from './reactive.module';
+
+describe('ReactiveModule', () => {
+  let reactiveModule: ReactiveModule;
+
+  beforeEach(() => {
+    reactiveModule = new ReactiveModule();
+  });
+
+  it('should create an instance', () => {
+    expect(reactiveModule).toBeTruthy();
+  });
+});

aio/content/examples/forms-overview/src/app/reactive/reactive.module.ts

@@ -0,0 +1,14 @@
+import { NgModule } from '@angular/core';
+import { CommonModule } from '@angular/common';
+import { ReactiveNameComponent } from './name/name.component';
+import { ReactiveFormsModule } from '@angular/forms';
+
+@NgModule({
+  imports: [
+    CommonModule,
+    ReactiveFormsModule
+  ],
+  declarations: [ReactiveNameComponent],
+  exports: [ReactiveNameComponent],
+})
+export class ReactiveModule { }