Angular 2 Custom validation unit testing

Question

i'm writing custom angular(Angular 2.0.0) validation, following this guide https://angular.io/docs/ts/latest/cookbook/form-validation.html#!#custom-validation .

@Directive({
  selector: '[ngModel][emailValidator]',
  providers: [{provide: NG_VALIDATORS, useExisting: EmailValidatorDirective, multi: true}]
})
export class EmailValidatorDirective implements Validator 

Now i'm trying to add unit test to my custom validation directive.

beforeEach(() => {
      fixture = TestBed.createComponent(EmailComponent);
      component = fixture.componentInstance;
      de = fixture.debugElement;
      el = de.nativeElement;
      component = de.componentInstance;
      emailField = de.query(By.css('input')).nativeElement;
    });

I'm accessing all these object, but no one has any information about the validity of my input. Does anyone has any idea how to access the NgControl of my input inside the Unit Tests, or how can i check for valid/invalid(custom validation) input field.

Answer 1

What you need to do is get the injector that has the NgForm. It took me a while to figure it out. I thought you could just get it from the debugElement, but it looks like you need to get it from it's child¹.

let form: NgForm = fixture.debugElement.children[0].injector.get(NgForm);

The you can just get individual controls from the form group with

let emailControl = form.control.get('email');
expect(emailControl.valid).toBe(true);

Or you can just check the form for a specific error

expect(form.control.hasError('emailInvalid', ['email'])).toBe(true);

Below is a complete test

import { Component, forwardRef, Directive } from '@angular/core';
import { TestBed, getTestBed, async } from '@angular/core/testing';
import { FormsModule, NG_VALIDATORS, Validator, AbstractControl, NgForm } from '@angular/forms';
import { dispatchEvent } from '@angular/platform-browser/testing/browser_util';
import { By } from '@angular/platform-browser';

@Directive({
  selector: '[ngModel][validEmail]',
  providers: [
    {
      provide: NG_VALIDATORS,
      useExisting: forwardRef(() => EmailValidatorDirective),
      multi: true
    }
  ]
})
class EmailValidatorDirective implements Validator {

  validate(c: AbstractControl): { [key: string]: any } {
    if (c.value !== '[email protected]') {
      return { notPeeskillet: true };
    }
    return null;
  }
}

@Component({
  template: `
    <form>
      <input name="email" [ngModel]="email" validEmail />
    </form>
  `
})
class TestComponent {
  email;
}

describe('component: TestComponent', () => {
  beforeEach(() => {
    TestBed.configureTestingModule({
      imports: [FormsModule],
      declarations: [TestComponent, EmailValidatorDirective]
    });
  });

  it('should validate', async(() => {
    let fixture = TestBed.createComponent(TestComponent);
    let comp = fixture.componentInstance;
    let debug = fixture.debugElement;
    let input = debug.query(By.css('[name=email]'));

    fixture.detectChanges();
    fixture.whenStable().then(() => {
      input.nativeElement.value = '[email protected]';
      dispatchEvent(input.nativeElement, 'input');
      fixture.detectChanges();

      let form: NgForm = debug.children[0].injector.get(NgForm);
      let control = form.control.get('email');
      expect(control.hasError('notPeeskillet')).toBe(true);
      expect(form.control.valid).toEqual(false);
      expect(form.control.hasError('notPeeskillet', ['email'])).toEqual(true);

      input.nativeElement.value = '[email protected]';
      dispatchEvent(input.nativeElement, 'input');
      fixture.detectChanges();

      expect(control.hasError('notPeeskillet')).toBe(false);
      expect(form.control.valid).toEqual(true);
      expect(form.control.hasError('notPeeskillet', ['email'])).toEqual(false);
    });
  }));
});

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_{1 - Found it in the source code tests}