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

import {ɵgetDOM as getDOM} from '@angular/common';
import {Component, Directive, forwardRef, Input, NgModule, OnDestroy, Type} from '@angular/core';
import {ComponentFixture, fakeAsync, TestBed, tick} from '@angular/core/testing';
import {expect} from '@angular/core/testing/src/testing_internal';
import {AbstractControl, AsyncValidator, AsyncValidatorFn, COMPOSITION_BUFFER_MODE, ControlValueAccessor, DefaultValueAccessor, FormArray, FormControl, FormControlDirective, FormControlName, FormGroup, FormGroupDirective, FormsModule, MaxValidator, MinValidator, NG_ASYNC_VALIDATORS, NG_VALIDATORS, NG_VALUE_ACCESSOR, ReactiveFormsModule, Validator, Validators} from '@angular/forms';
import {By} from '@angular/platform-browser/src/dom/debug/by';
import {dispatchEvent, sortedClassList} from '@angular/platform-browser/testing/src/browser_util';
import {merge, NEVER, of, Subscription, timer} from 'rxjs';
import {map, tap} from 'rxjs/operators';

import {MyInput, MyInputForm} from './value_accessor_integration_spec';

// Produces a new @Directive (with a given selector) that represents a validator class.
function createValidatorClass(selector: string) {
  @Directive({
    selector,
    providers: [{
      provide: NG_VALIDATORS,
      useClass: forwardRef(() => CustomValidator),
      multi: true,
    }]
  })
  class CustomValidator implements Validator {
    validate(control: AbstractControl) {
      return null;
    }
  }
  return CustomValidator;
}

// Produces a new @Directive (with a given selector) that represents an async validator class.
function createAsyncValidatorClass(selector: string) {
  @Directive({
    selector,
    providers: [{
      provide: NG_ASYNC_VALIDATORS,
      useClass: forwardRef(() => CustomValidator),
      multi: true,
    }]
  })
  class CustomValidator implements AsyncValidator {
    validate(control: AbstractControl) {
      return Promise.resolve(null);
    }
  }
  return CustomValidator;
}

// Produces a new @Directive (with a given selector) that represents a value accessor.
function createControlValueAccessor(selector: string) {
  @Directive({
    selector,
    providers: [{
      provide: NG_VALUE_ACCESSOR,
      useExisting: forwardRef(() => CustomValueAccessor),
      multi: true,
    }]
  })
  class CustomValueAccessor implements ControlValueAccessor {
    writeValue(value: any) {}
    registerOnChange(fn: (value: any) => void) {}
    registerOnTouched(fn: any) {}
  }
  return CustomValueAccessor;
}

// Pre-create classes for validators.
const ViewValidatorA = createValidatorClass('[validators-a]');
const ViewValidatorB = createValidatorClass('[validators-b]');
const ViewValidatorC = createValidatorClass('[validators-c]');

// Pre-create classes for async validators.
const AsyncViewValidatorA = createAsyncValidatorClass('[validators-a]');
const AsyncViewValidatorB = createAsyncValidatorClass('[validators-b]');
const AsyncViewValidatorC = createAsyncValidatorClass('[validators-c]');

// Pre-create classes for value accessors.
const ValueAccessorA = createControlValueAccessor('[cva-a]');
const ValueAccessorB = createControlValueAccessor('[cva-b]');

{
  describe('reactive forms integration tests', () => {
    function initTest<T>(component: Type<T>, ...directives: Type<any>[]): ComponentFixture<T> {
      TestBed.configureTestingModule(
          {declarations: [component, ...directives], imports: [FormsModule, ReactiveFormsModule]});
      return TestBed.createComponent(component);
    }

    function initReactiveFormsTest<T>(
        component: Type<T>, ...directives: Type<any>[]): ComponentFixture<T> {
      TestBed.configureTestingModule(
          {declarations: [component, ...directives], imports: [ReactiveFormsModule]});
      return TestBed.createComponent(component);
    }

    // Helper method that attaches a spy to a `validate` function on a Validator class.
    function validatorSpyOn(validatorClass: any) {
      return spyOn(validatorClass.prototype, 'validate').and.callThrough();
    }

    describe('basic functionality', () => {
      it('should work with single controls', () => {
        const fixture = initTest(FormControlComp);
        const control = new FormControl('old value');
        fixture.componentInstance.control = control;
        fixture.detectChanges();

        // model -> view
        const input = fixture.debugElement.query(By.css('input'));
        expect(input.nativeElement.value).toEqual('old value');

        input.nativeElement.value = 'updated value';
        dispatchEvent(input.nativeElement, 'input');

        // view -> model
        expect(control.value).toEqual('updated value');
      });

      it('should work with formGroups (model -> view)', () => {
        const fixture = initTest(FormGroupComp);
        fixture.componentInstance.form = new FormGroup({'login': new FormControl('loginValue')});
        fixture.detectChanges();

        const input = fixture.debugElement.query(By.css('input'));
        expect(input.nativeElement.value).toEqual('loginValue');
      });

      it('should add novalidate by default to form', () => {
        const fixture = initTest(FormGroupComp);
        fixture.componentInstance.form = new FormGroup({'login': new FormControl('loginValue')});
        fixture.detectChanges();

        const form = fixture.debugElement.query(By.css('form'));
        expect(form.nativeElement.getAttribute('novalidate')).toEqual('');
      });

      it('work with formGroups (view -> model)', () => {
        const fixture = initTest(FormGroupComp);
        const form = new FormGroup({'login': new FormControl('oldValue')});
        fixture.componentInstance.form = form;
        fixture.detectChanges();

        const input = fixture.debugElement.query(By.css('input'));
        input.nativeElement.value = 'updatedValue';
        dispatchEvent(input.nativeElement, 'input');

        expect(form.value).toEqual({'login': 'updatedValue'});
      });
    });

    describe('re-bound form groups', () => {
      it('should update DOM elements initially', () => {
        const fixture = initTest(FormGroupComp);
        fixture.componentInstance.form = new FormGroup({'login': new FormControl('oldValue')});
        fixture.detectChanges();

        fixture.componentInstance.form = new FormGroup({'login': new FormControl('newValue')});
        fixture.detectChanges();

        const input = fixture.debugElement.query(By.css('input'));
        expect(input.nativeElement.value).toEqual('newValue');
      });

      it('should update model when UI changes', () => {
        const fixture = initTest(FormGroupComp);
        fixture.componentInstance.form = new FormGroup({'login': new FormControl('oldValue')});
        fixture.detectChanges();

        const newForm = new FormGroup({'login': new FormControl('newValue')});
        fixture.componentInstance.form = newForm;
        fixture.detectChanges();

        const input = fixture.debugElement.query(By.css('input'));
        input.nativeElement.value = 'Nancy';
        dispatchEvent(input.nativeElement, 'input');
        fixture.detectChanges();

        expect(newForm.value).toEqual({login: 'Nancy'});

        newForm.setValue({login: 'Carson'});
        fixture.detectChanges();
        expect(input.nativeElement.value).toEqual('Carson');
      });

      it('should update nested form group model when UI changes', () => {
        const fixture = initTest(NestedFormGroupComp);
        fixture.componentInstance.form = new FormGroup(
            {'signin': new FormGroup({'login': new FormControl(), 'password': new FormControl()})});
        fixture.detectChanges();

        const newForm = new FormGroup({
          'signin': new FormGroup(
              {'login': new FormControl('Nancy'), 'password': new FormControl('secret')})
        });
        fixture.componentInstance.form = newForm;
        fixture.detectChanges();

        const inputs = fixture.debugElement.queryAll(By.css('input'));
        expect(inputs[0].nativeElement.value).toEqual('Nancy');
        expect(inputs[1].nativeElement.value).toEqual('secret');

        inputs[0].nativeElement.value = 'Carson';
        dispatchEvent(inputs[0].nativeElement, 'input');
        fixture.detectChanges();

        expect(newForm.value).toEqual({signin: {login: 'Carson', password: 'secret'}});

        newForm.setValue({signin: {login: 'Bess', password: 'otherpass'}});
        fixture.detectChanges();
        expect(inputs[0].nativeElement.value).toEqual('Bess');
      });

      it('should pick up dir validators from form controls', () => {
        const fixture = initTest(LoginIsEmptyWrapper, LoginIsEmptyValidator);
        const form = new FormGroup({
          'login': new FormControl(''),
          'min': new FormControl(''),
          'max': new FormControl(''),
          'pattern': new FormControl('')
        });
        fixture.componentInstance.form = form;
        fixture.detectChanges();
        expect(form.get('login')!.errors).toEqual({required: true});

        const newForm = new FormGroup({
          'login': new FormControl(''),
          'min': new FormControl(''),
          'max': new FormControl(''),
          'pattern': new FormControl('')
        });
        fixture.componentInstance.form = newForm;
        fixture.detectChanges();

        expect(newForm.get('login')!.errors).toEqual({required: true});
      });

      it('should pick up dir validators from nested form groups', () => {
        const fixture = initTest(NestedFormGroupComp, LoginIsEmptyValidator);
        const form = new FormGroup({
          'signin': new FormGroup({'login': new FormControl(''), 'password': new FormControl('')})
        });
        fixture.componentInstance.form = form;
        fixture.detectChanges();
        expect(form.get('signin')!.valid).toBe(false);

        const newForm = new FormGroup({
          'signin': new FormGroup({'login': new FormControl(''), 'password': new FormControl('')})
        });
        fixture.componentInstance.form = newForm;
        fixture.detectChanges();

        expect(form.get('signin')!.valid).toBe(false);
      });

      it('should strip named controls that are not found', () => {
        const fixture = initTest(NestedFormGroupComp, LoginIsEmptyValidator);
        const form = new FormGroup({
          'signin': new FormGroup({'login': new FormControl(''), 'password': new FormControl('')})
        });
        fixture.componentInstance.form = form;
        fixture.detectChanges();

        form.addControl('email', new FormControl('email'));
        fixture.detectChanges();

        let emailInput = fixture.debugElement.query(By.css('[formControlName="email"]'));
        expect(emailInput.nativeElement.value).toEqual('email');

        const newForm = new FormGroup({
          'signin': new FormGroup({'login': new FormControl(''), 'password': new FormControl('')})
        });
        fixture.componentInstance.form = newForm;
        fixture.detectChanges();

        emailInput = fixture.debugElement.query(By.css('[formControlName="email"]'));
        expect(emailInput as any).toBe(null);  // TODO: Review use of `any` here (#19904)
      });

      it('should strip array controls that are not found', () => {
        const fixture = initTest(FormArrayComp);
        const cityArray = new FormArray([new FormControl('SF'), new FormControl('NY')]);
        const form = new FormGroup({cities: cityArray});
        fixture.componentInstance.form = form;
        fixture.componentInstance.cityArray = cityArray;
        fixture.detectChanges();

        let inputs = fixture.debugElement.queryAll(By.css('input'));
        expect(inputs[2]).not.toBeDefined();
        cityArray.push(new FormControl('LA'));
        fixture.detectChanges();

        inputs = fixture.debugElement.queryAll(By.css('input'));
        expect(inputs[2]).toBeDefined();

        const newArr = new FormArray([new FormControl('SF'), new FormControl('NY')]);
        const newForm = new FormGroup({cities: newArr});
        fixture.componentInstance.form = newForm;
        fixture.componentInstance.cityArray = newArr;
        fixture.detectChanges();

        inputs = fixture.debugElement.queryAll(By.css('input'));
        expect(inputs[2]).not.toBeDefined();
      });

      describe('nested control rebinding', () => {
        it('should attach dir to control when leaf control changes', () => {
          const form = new FormGroup({'login': new FormControl('oldValue')});
          const fixture = initTest(FormGroupComp);
          fixture.componentInstance.form = form;
          fixture.detectChanges();

          form.removeControl('login');
          form.addControl('login', new FormControl('newValue'));
          fixture.detectChanges();

          const input = fixture.debugElement.query(By.css('input'));
          expect(input.nativeElement.value).toEqual('newValue');

          input.nativeElement.value = 'user input';
          dispatchEvent(input.nativeElement, 'input');
          fixture.detectChanges();

          expect(form.value).toEqual({login: 'user input'});

          form.setValue({login: 'Carson'});
          fixture.detectChanges();
          expect(input.nativeElement.value).toEqual('Carson');
        });

        it('should attach dirs to all child controls when group control changes', () => {
          const fixture = initTest(NestedFormGroupComp, LoginIsEmptyValidator);
          const form = new FormGroup({
            signin: new FormGroup(
                {login: new FormControl('oldLogin'), password: new FormControl('oldPassword')})
          });
          fixture.componentInstance.form = form;
          fixture.detectChanges();

          form.removeControl('signin');
          form.addControl(
              'signin',
              new FormGroup(
                  {login: new FormControl('newLogin'), password: new FormControl('newPassword')}));
          fixture.detectChanges();

          const inputs = fixture.debugElement.queryAll(By.css('input'));
          expect(inputs[0].nativeElement.value).toEqual('newLogin');
          expect(inputs[1].nativeElement.value).toEqual('newPassword');

          inputs[0].nativeElement.value = 'user input';
          dispatchEvent(inputs[0].nativeElement, 'input');
          fixture.detectChanges();

          expect(form.value).toEqual({signin: {login: 'user input', password: 'newPassword'}});

          form.setValue({signin: {login: 'Carson', password: 'Drew'}});
          fixture.detectChanges();
          expect(inputs[0].nativeElement.value).toEqual('Carson');
          expect(inputs[1].nativeElement.value).toEqual('Drew');
        });

        it('should attach dirs to all present child controls when array control changes', () => {
          const fixture = initTest(FormArrayComp);
          const cityArray = new FormArray([new FormControl('SF'), new FormControl('NY')]);
          const form = new FormGroup({cities: cityArray});
          fixture.componentInstance.form = form;
          fixture.componentInstance.cityArray = cityArray;
          fixture.detectChanges();

          form.removeControl('cities');
          form.addControl('cities', new FormArray([new FormControl('LA')]));
          fixture.detectChanges();

          const input = fixture.debugElement.query(By.css('input'));
          expect(input.nativeElement.value).toEqual('LA');

          input.nativeElement.value = 'MTV';
          dispatchEvent(input.nativeElement, 'input');
          fixture.detectChanges();

          expect(form.value).toEqual({cities: ['MTV']});

          form.setValue({cities: ['LA']});
          fixture.detectChanges();
          expect(input.nativeElement.value).toEqual('LA');
        });

        it('should remove controls correctly after re-binding a form array', () => {
          const fixture = initTest(FormArrayComp);
          const cityArray =
              new FormArray([new FormControl('SF'), new FormControl('NY'), new FormControl('LA')]);
          const form = new FormGroup({cities: cityArray});
          fixture.componentInstance.form = form;
          fixture.componentInstance.cityArray = cityArray;
          fixture.detectChanges();

          const newArr =
              new FormArray([new FormControl('SF'), new FormControl('NY'), new FormControl('LA')]);
          fixture.componentInstance.cityArray = newArr;
          form.setControl('cities', newArr);
          fixture.detectChanges();

          newArr.removeAt(0);
          fixture.detectChanges();

          let inputs = fixture.debugElement.queryAll(By.css('input'));
          expect(inputs[0].nativeElement.value).toEqual('NY');
          expect(inputs[1].nativeElement.value).toEqual('LA');

          let firstInput = inputs[0].nativeElement;
          firstInput.value = 'new value';
          dispatchEvent(firstInput, 'input');
          fixture.detectChanges();

          expect(newArr.value).toEqual(['new value', 'LA']);

          newArr.removeAt(0);
          fixture.detectChanges();

          firstInput = fixture.debugElement.query(By.css('input')).nativeElement;
          firstInput.value = 'last one';
          dispatchEvent(firstInput, 'input');
          fixture.detectChanges();

          expect(newArr.value).toEqual(['last one']);

          newArr.get([0])!.setValue('set value');
          fixture.detectChanges();

          firstInput = fixture.debugElement.query(By.css('input')).nativeElement;
          expect(firstInput.value).toEqual('set value');
        });

        it('should submit properly after removing controls on a re-bound array', () => {
          const fixture = initTest(FormArrayComp);
          const cityArray =
              new FormArray([new FormControl('SF'), new FormControl('NY'), new FormControl('LA')]);
          const form = new FormGroup({cities: cityArray});
          fixture.componentInstance.form = form;
          fixture.componentInstance.cityArray = cityArray;
          fixture.detectChanges();

          const newArr =
              new FormArray([new FormControl('SF'), new FormControl('NY'), new FormControl('LA')]);
          fixture.componentInstance.cityArray = newArr;
          form.setControl('cities', newArr);
          fixture.detectChanges();

          newArr.removeAt(0);
          fixture.detectChanges();

          const formEl = fixture.debugElement.query(By.css('form'));
          expect(() => dispatchEvent(formEl.nativeElement, 'submit')).not.toThrowError();
        });

        it('should insert controls properly on a re-bound array', () => {
          const fixture = initTest(FormArrayComp);
          const cityArray = new FormArray([new FormControl('SF'), new FormControl('NY')]);
          const form = new FormGroup({cities: cityArray});
          fixture.componentInstance.form = form;
          fixture.componentInstance.cityArray = cityArray;
          fixture.detectChanges();

          const newArr = new FormArray([new FormControl('SF'), new FormControl('NY')]);
          fixture.componentInstance.cityArray = newArr;
          form.setControl('cities', newArr);
          fixture.detectChanges();

          newArr.insert(1, new FormControl('LA'));
          fixture.detectChanges();

          let inputs = fixture.debugElement.queryAll(By.css('input'));
          expect(inputs[0].nativeElement.value).toEqual('SF');
          expect(inputs[1].nativeElement.value).toEqual('LA');
          expect(inputs[2].nativeElement.value).toEqual('NY');

          const lastInput = inputs[2].nativeElement;
          lastInput.value = 'Tulsa';
          dispatchEvent(lastInput, 'input');
          fixture.detectChanges();

          expect(newArr.value).toEqual(['SF', 'LA', 'Tulsa']);

          newArr.get([2])!.setValue('NY');
          fixture.detectChanges();

          expect(lastInput.value).toEqual('NY');
        });
      });
    });

    describe('form arrays', () => {
      it('should support form arrays', () => {
        const fixture = initTest(FormArrayComp);
        const cityArray = new FormArray([new FormControl('SF'), new FormControl('NY')]);
        const form = new FormGroup({cities: cityArray});
        fixture.componentInstance.form = form;
        fixture.componentInstance.cityArray = cityArray;
        fixture.detectChanges();

        const inputs = fixture.debugElement.queryAll(By.css('input'));

        // model -> view
        expect(inputs[0].nativeElement.value).toEqual('SF');
        expect(inputs[1].nativeElement.value).toEqual('NY');
        expect(form.value).toEqual({cities: ['SF', 'NY']});

        inputs[0].nativeElement.value = 'LA';
        dispatchEvent(inputs[0].nativeElement, 'input');
        fixture.detectChanges();

        //  view -> model
        expect(form.value).toEqual({cities: ['LA', 'NY']});
      });

      it('should support pushing new controls to form arrays', () => {
        const fixture = initTest(FormArrayComp);
        const cityArray = new FormArray([new FormControl('SF'), new FormControl('NY')]);
        const form = new FormGroup({cities: cityArray});
        fixture.componentInstance.form = form;
        fixture.componentInstance.cityArray = cityArray;
        fixture.detectChanges();

        cityArray.push(new FormControl('LA'));
        fixture.detectChanges();

        const inputs = fixture.debugElement.queryAll(By.css('input'));
        expect(inputs[2].nativeElement.value).toEqual('LA');
        expect(form.value).toEqual({cities: ['SF', 'NY', 'LA']});
      });

      it('should support form groups nested in form arrays', () => {
        const fixture = initTest(FormArrayNestedGroup);
        const cityArray = new FormArray([
          new FormGroup({town: new FormControl('SF'), state: new FormControl('CA')}),
          new FormGroup({town: new FormControl('NY'), state: new FormControl('NY')})
        ]);
        const form = new FormGroup({cities: cityArray});
        fixture.componentInstance.form = form;
        fixture.componentInstance.cityArray = cityArray;
        fixture.detectChanges();

        const inputs = fixture.debugElement.queryAll(By.css('input'));
        expect(inputs[0].nativeElement.value).toEqual('SF');
        expect(inputs[1].nativeElement.value).toEqual('CA');
        expect(inputs[2].nativeElement.value).toEqual('NY');
        expect(inputs[3].nativeElement.value).toEqual('NY');
        expect(form.value).toEqual({
          cities: [{town: 'SF', state: 'CA'}, {town: 'NY', state: 'NY'}]
        });

        inputs[0].nativeElement.value = 'LA';
        dispatchEvent(inputs[0].nativeElement, 'input');
        fixture.detectChanges();

        expect(form.value).toEqual({
          cities: [{town: 'LA', state: 'CA'}, {town: 'NY', state: 'NY'}]
        });
      });
    });

    describe('programmatic changes', () => {
      it('should update the value in the DOM when setValue() is called', () => {
        const fixture = initTest(FormGroupComp);
        const login = new FormControl('oldValue');
        const form = new FormGroup({'login': login});
        fixture.componentInstance.form = form;
        fixture.detectChanges();

        login.setValue('newValue');
        fixture.detectChanges();

        const input = fixture.debugElement.query(By.css('input'));
        expect(input.nativeElement.value).toEqual('newValue');
      });

      describe('disabled controls', () => {
        it('should add disabled attribute to an individual control when instantiated as disabled',
           () => {
             const fixture = initTest(FormControlComp);
             const control = new FormControl({value: 'some value', disabled: true});
             fixture.componentInstance.control = control;
             fixture.detectChanges();

             const input = fixture.debugElement.query(By.css('input'));
             expect(input.nativeElement.disabled).toBe(true);

             control.enable();
             fixture.detectChanges();
             expect(input.nativeElement.disabled).toBe(false);
           });

        it('should add disabled attribute to formControlName when instantiated as disabled', () => {
          const fixture = initTest(FormGroupComp);
          const control = new FormControl({value: 'some value', disabled: true});
          fixture.componentInstance.form = new FormGroup({login: control});
          fixture.componentInstance.control = control;
          fixture.detectChanges();

          const input = fixture.debugElement.query(By.css('input'));
          expect(input.nativeElement.disabled).toBe(true);

          control.enable();
          fixture.detectChanges();
          expect(input.nativeElement.disabled).toBe(false);
        });

        it('should add disabled attribute to an individual control when disable() is called',
           () => {
             const fixture = initTest(FormControlComp);
             const control = new FormControl('some value');
             fixture.componentInstance.control = control;
             fixture.detectChanges();

             control.disable();
             fixture.detectChanges();

             const input = fixture.debugElement.query(By.css('input'));
             expect(input.nativeElement.disabled).toBe(true);

             control.enable();
             fixture.detectChanges();
             expect(input.nativeElement.disabled).toBe(false);
           });

        it('should add disabled attribute to child controls when disable() is called on group',
           () => {
             const fixture = initTest(FormGroupComp);
             const form = new FormGroup({'login': new FormControl('login')});
             fixture.componentInstance.form = form;
             fixture.detectChanges();

             form.disable();
             fixture.detectChanges();

             const inputs = fixture.debugElement.queryAll(By.css('input'));
             expect(inputs[0].nativeElement.disabled).toBe(true);

             form.enable();
             fixture.detectChanges();
             expect(inputs[0].nativeElement.disabled).toBe(false);
           });


        it('should not add disabled attribute to custom controls when disable() is called', () => {
          const fixture = initTest(MyInputForm, MyInput);
          const control = new FormControl('some value');
          fixture.componentInstance.form = new FormGroup({login: control});
          fixture.detectChanges();

          control.disable();
          fixture.detectChanges();

          const input = fixture.debugElement.query(By.css('my-input'));
          expect(input.nativeElement.getAttribute('disabled')).toBe(null);
        });
      });

      describe('dynamic change of FormGroup and FormArray shapes', () => {
        it('should handle FormControl and FormGroup swap', () => {
          @Component({
            template: `
              <form [formGroup]="form">
                <input formControlName="name" id="standalone-id" *ngIf="!showAsGroup">
                <ng-container formGroupName="name" *ngIf="showAsGroup">
                  <input formControlName="control" id="inside-group-id">
                </ng-container>
              </form>
            `
          })
          class App {
            showAsGroup = false;
            form!: FormGroup;

            useStandaloneControl() {
              this.showAsGroup = false;
              this.form = new FormGroup({
                name: new FormControl('standalone'),
              });
            }

            useControlInsideGroup() {
              this.showAsGroup = true;
              this.form = new FormGroup({
                name: new FormGroup({
                  control: new FormControl('inside-group'),
                })
              });
            }
          }

          const fixture = initTest(App);
          fixture.componentInstance.useStandaloneControl();
          fixture.detectChanges();

          let input = fixture.nativeElement.querySelector('input');
          expect(input.id).toBe('standalone-id');
          expect(input.value).toBe('standalone');

          // Replace `FormControl` with `FormGroup` at the same location
          // in data model and trigger change detection.
          fixture.componentInstance.useControlInsideGroup();
          fixture.detectChanges();

          input = fixture.nativeElement.querySelector('input');
          expect(input.id).toBe('inside-group-id');
          expect(input.value).toBe('inside-group');

          // Swap `FormGroup` with `FormControl` back at the same location
          // in data model and trigger change detection.
          fixture.componentInstance.useStandaloneControl();
          fixture.detectChanges();

          input = fixture.nativeElement.querySelector('input');
          expect(input.id).toBe('standalone-id');
          expect(input.value).toBe('standalone');
        });

        it('should handle FormControl and FormArray swap', () => {
          @Component({
            template: `
              <form [formGroup]="form">
                <input formControlName="name" id="standalone-id" *ngIf="!showAsArray">
                <ng-container formArrayName="name" *ngIf="showAsArray">
                  <input formControlName="0" id="inside-array-id">
                </ng-container>
              </form>
            `
          })
          class App {
            showAsArray = false;
            form!: FormGroup;

            useStandaloneControl() {
              this.showAsArray = false;
              this.form = new FormGroup({
                name: new FormControl('standalone'),
              });
            }

            useControlInsideArray() {
              this.showAsArray = true;
              this.form = new FormGroup({
                name: new FormArray([
                  new FormControl('inside-array')  //
                ])
              });
            }
          }

          const fixture = initTest(App);
          fixture.componentInstance.useStandaloneControl();
          fixture.detectChanges();

          let input = fixture.nativeElement.querySelector('input');
          expect(input.id).toBe('standalone-id');
          expect(input.value).toBe('standalone');

          // Replace `FormControl` with `FormArray` at the same location
          // in data model and trigger change detection.
          fixture.componentInstance.useControlInsideArray();
          fixture.detectChanges();

          input = fixture.nativeElement.querySelector('input');
          expect(input.id).toBe('inside-array-id');
          expect(input.value).toBe('inside-array');

          // Swap `FormArray` with `FormControl` back at the same location
          // in data model and trigger change detection.
          fixture.componentInstance.useStandaloneControl();
          fixture.detectChanges();

          input = fixture.nativeElement.querySelector('input');
          expect(input.id).toBe('standalone-id');
          expect(input.value).toBe('standalone');
        });

        it('should handle FormGroup and FormArray swap', () => {
          @Component({
            template: `
              <form [formGroup]="form">
                <ng-container formGroupName="name" *ngIf="!showAsArray">
                  <input formControlName="control" id="inside-group-id">
                </ng-container>
                <ng-container formArrayName="name" *ngIf="showAsArray">
                  <input formControlName="0" id="inside-array-id">
                </ng-container>
              </form>
            `
          })
          class App {
            showAsArray = false;
            form!: FormGroup;

            useControlInsideGroup() {
              this.showAsArray = false;
              this.form = new FormGroup({
                name: new FormGroup({
                  control: new FormControl('inside-group'),
                })
              });
            }

            useControlInsideArray() {
              this.showAsArray = true;
              this.form = new FormGroup({
                name: new FormArray([
                  new FormControl('inside-array')  //
                ])
              });
            }
          }

          const fixture = initTest(App);
          fixture.componentInstance.useControlInsideGroup();
          fixture.detectChanges();

          let input = fixture.nativeElement.querySelector('input');
          expect(input.id).toBe('inside-group-id');
          expect(input.value).toBe('inside-group');

          // Replace `FormGroup` with `FormArray` at the same location
          // in data model and trigger change detection.
          fixture.componentInstance.useControlInsideArray();
          fixture.detectChanges();

          input = fixture.nativeElement.querySelector('input');
          expect(input.id).toBe('inside-array-id');
          expect(input.value).toBe('inside-array');

          // Swap `FormArray` with `FormGroup` back at the same location
          // in data model and trigger change detection.
          fixture.componentInstance.useControlInsideGroup();
          fixture.detectChanges();

          input = fixture.nativeElement.querySelector('input');
          expect(input.id).toBe('inside-group-id');
          expect(input.value).toBe('inside-group');
        });
      });
    });

    describe('user input', () => {
      it('should mark controls as touched after interacting with the DOM control', () => {
        const fixture = initTest(FormGroupComp);
        const login = new FormControl('oldValue');
        const form = new FormGroup({'login': login});
        fixture.componentInstance.form = form;
        fixture.detectChanges();

        const loginEl = fixture.debugElement.query(By.css('input'));
        expect(login.touched).toBe(false);

        dispatchEvent(loginEl.nativeElement, 'blur');

        expect(login.touched).toBe(true);
      });
    });

    describe('submit and reset events', () => {
      it('should emit ngSubmit event with the original submit event on submit', () => {
        const fixture = initTest(FormGroupComp);
        fixture.componentInstance.form = new FormGroup({'login': new FormControl('loginValue')});
        fixture.componentInstance.event = null!;
        fixture.detectChanges();

        const formEl = fixture.debugElement.query(By.css('form')).nativeElement;
        dispatchEvent(formEl, 'submit');

        fixture.detectChanges();
        expect(fixture.componentInstance.event.type).toEqual('submit');
      });

      it('should mark formGroup as submitted on submit event', () => {
        const fixture = initTest(FormGroupComp);
        fixture.componentInstance.form = new FormGroup({'login': new FormControl('loginValue')});
        fixture.detectChanges();

        const formGroupDir = fixture.debugElement.children[0].injector.get(FormGroupDirective);
        expect(formGroupDir.submitted).toBe(false);

        const formEl = fixture.debugElement.query(By.css('form')).nativeElement;
        dispatchEvent(formEl, 'submit');

        fixture.detectChanges();
        expect(formGroupDir.submitted).toEqual(true);
      });

      it('should set value in UI when form resets to that value programmatically', () => {
        const fixture = initTest(FormGroupComp);
        const login = new FormControl('some value');
        const form = new FormGroup({'login': login});
        fixture.componentInstance.form = form;
        fixture.detectChanges();

        const loginEl = fixture.debugElement.query(By.css('input')).nativeElement;
        expect(loginEl.value).toBe('some value');

        form.reset({'login': 'reset value'});
        expect(loginEl.value).toBe('reset value');
      });

      it('should clear value in UI when form resets programmatically', () => {
        const fixture = initTest(FormGroupComp);
        const login = new FormControl('some value');
        const form = new FormGroup({'login': login});
        fixture.componentInstance.form = form;
        fixture.detectChanges();

        const loginEl = fixture.debugElement.query(By.css('input')).nativeElement;
        expect(loginEl.value).toBe('some value');

        form.reset();
        expect(loginEl.value).toBe('');
      });
    });

    describe('value changes and status changes', () => {
      it('should mark controls as dirty before emitting a value change event', () => {
        const fixture = initTest(FormGroupComp);
        const login = new FormControl('oldValue');
        fixture.componentInstance.form = new FormGroup({'login': login});
        fixture.detectChanges();

        login.valueChanges.subscribe(() => {
          expect(login.dirty).toBe(true);
        });

        const loginEl = fixture.debugElement.query(By.css('input')).nativeElement;
        loginEl.value = 'newValue';

        dispatchEvent(loginEl, 'input');
      });

      it('should mark control as pristine before emitting a value change event when resetting ',
         () => {
           const fixture = initTest(FormGroupComp);
           const login = new FormControl('oldValue');
           const form = new FormGroup({'login': login});
           fixture.componentInstance.form = form;
           fixture.detectChanges();

           const loginEl = fixture.debugElement.query(By.css('input')).nativeElement;
           loginEl.value = 'newValue';
           dispatchEvent(loginEl, 'input');

           expect(login.pristine).toBe(false);

           login.valueChanges.subscribe(() => {
             expect(login.pristine).toBe(true);
           });

           form.reset();
         });
    });

    describe('setting status classes', () => {
      it('should not assign status on standalone <form> element', () => {
        @Component({
          selector: 'form-comp',
          template: `
            <form></form>
          `
        })
        class FormComp {
        }

        const fixture = initReactiveFormsTest(FormComp);
        fixture.detectChanges();

        const form = fixture.debugElement.query(By.css('form')).nativeElement;
        // Expect no classes added to the <form> element since it has no
        // reactive directives attached and only ReactiveForms module is used.
        expect(sortedClassList(form)).toEqual([]);
      });

      it('should not assign status on standalone <form> element with form control inside', () => {
        @Component({
          selector: 'form-comp',
          template: `
            <form>
              <input type="text" [formControl]="control">
            </form>
          `
        })
        class FormComp {
          control = new FormControl('abc');
        }
        const fixture = initReactiveFormsTest(FormComp);
        fixture.detectChanges();

        const form = fixture.debugElement.query(By.css('form')).nativeElement;
        // Expect no classes added to the <form> element since it has no
        // reactive directives attached and only ReactiveForms module is used.
        expect(sortedClassList(form)).toEqual([]);

        const input = fixture.debugElement.query(By.css('input')).nativeElement;
        expect(sortedClassList(input)).toEqual(['ng-pristine', 'ng-untouched', 'ng-valid']);
      });

      it('should work with single fields', () => {
        const fixture = initTest(FormControlComp);
        const control = new FormControl('', Validators.required);
        fixture.componentInstance.control = control;
        fixture.detectChanges();

        const input = fixture.debugElement.query(By.css('input')).nativeElement;
        expect(sortedClassList(input)).toEqual(['ng-invalid', 'ng-pristine', 'ng-untouched']);

        dispatchEvent(input, 'blur');
        fixture.detectChanges();

        expect(sortedClassList(input)).toEqual(['ng-invalid', 'ng-pristine', 'ng-touched']);

        input.value = 'updatedValue';
        dispatchEvent(input, 'input');
        fixture.detectChanges();

        expect(sortedClassList(input)).toEqual(['ng-dirty', 'ng-touched', 'ng-valid']);
      });

      it('should work with single fields and async validators', fakeAsync(() => {
           const fixture = initTest(FormControlComp);
           const control = new FormControl('', null!, uniqLoginAsyncValidator('good'));
           fixture.debugElement.componentInstance.control = control;
           fixture.detectChanges();

           const input = fixture.debugElement.query(By.css('input')).nativeElement;
           expect(sortedClassList(input)).toEqual(['ng-pending', 'ng-pristine', 'ng-untouched']);

           dispatchEvent(input, 'blur');
           fixture.detectChanges();
           expect(sortedClassList(input)).toEqual(['ng-pending', 'ng-pristine', 'ng-touched']);

           input.value = 'good';
           dispatchEvent(input, 'input');
           tick();
           fixture.detectChanges();

           expect(sortedClassList(input)).toEqual(['ng-dirty', 'ng-touched', 'ng-valid']);
         }));

      it('should work with single fields that combines async and sync validators', fakeAsync(() => {
           const fixture = initTest(FormControlComp);
           const control =
               new FormControl('', Validators.required, uniqLoginAsyncValidator('good'));
           fixture.debugElement.componentInstance.control = control;
           fixture.detectChanges();

           const input = fixture.debugElement.query(By.css('input')).nativeElement;
           expect(sortedClassList(input)).toEqual(['ng-invalid', 'ng-pristine', 'ng-untouched']);

           dispatchEvent(input, 'blur');
           fixture.detectChanges();
           expect(sortedClassList(input)).toEqual(['ng-invalid', 'ng-pristine', 'ng-touched']);

           input.value = 'bad';
           dispatchEvent(input, 'input');
           fixture.detectChanges();

           expect(sortedClassList(input)).toEqual(['ng-dirty', 'ng-pending', 'ng-touched']);

           tick();
           fixture.detectChanges();

           expect(sortedClassList(input)).toEqual(['ng-dirty', 'ng-invalid', 'ng-touched']);

           input.value = 'good';
           dispatchEvent(input, 'input');
           tick();
           fixture.detectChanges();

           expect(sortedClassList(input)).toEqual(['ng-dirty', 'ng-touched', 'ng-valid']);
         }));

      it('should work with single fields in parent forms', () => {
        const fixture = initTest(FormGroupComp);
        const form = new FormGroup({'login': new FormControl('', Validators.required)});
        fixture.componentInstance.form = form;
        fixture.detectChanges();

        const input = fixture.debugElement.query(By.css('input')).nativeElement;
        expect(sortedClassList(input)).toEqual(['ng-invalid', 'ng-pristine', 'ng-untouched']);

        dispatchEvent(input, 'blur');
        fixture.detectChanges();

        expect(sortedClassList(input)).toEqual(['ng-invalid', 'ng-pristine', 'ng-touched']);

        input.value = 'updatedValue';
        dispatchEvent(input, 'input');
        fixture.detectChanges();

        expect(sortedClassList(input)).toEqual(['ng-dirty', 'ng-touched', 'ng-valid']);
      });

      it('should work with formGroup', () => {
        const fixture = initTest(FormGroupComp);
        const form = new FormGroup({'login': new FormControl('', Validators.required)});
        fixture.componentInstance.form = form;
        fixture.detectChanges();

        const input = fixture.debugElement.query(By.css('input')).nativeElement;
        const formEl = fixture.debugElement.query(By.css('form')).nativeElement;

        expect(sortedClassList(formEl)).toEqual(['ng-invalid', 'ng-pristine', 'ng-untouched']);

        dispatchEvent(input, 'blur');
        fixture.detectChanges();

        expect(sortedClassList(formEl)).toEqual(['ng-invalid', 'ng-pristine', 'ng-touched']);

        input.value = 'updatedValue';
        dispatchEvent(input, 'input');
        fixture.detectChanges();

        expect(sortedClassList(formEl)).toEqual(['ng-dirty', 'ng-touched', 'ng-valid']);
      });
    });

    describe('updateOn options', () => {
      describe('on blur', () => {
        it('should not update value or validity based on user input until blur', () => {
          const fixture = initTest(FormControlComp);
          const control = new FormControl('', {validators: Validators.required, updateOn: 'blur'});
          fixture.componentInstance.control = control;
          fixture.detectChanges();

          const input = fixture.debugElement.query(By.css('input')).nativeElement;
          input.value = 'Nancy';
          dispatchEvent(input, 'input');
          fixture.detectChanges();

          expect(control.value).toEqual('', 'Expected value to remain unchanged until blur.');
          expect(control.valid).toBe(false, 'Expected no validation to occur until blur.');

          dispatchEvent(input, 'blur');
          fixture.detectChanges();

          expect(control.value)
              .toEqual('Nancy', 'Expected value to change once control is blurred.');
          expect(control.valid).toBe(true, 'Expected validation to run once control is blurred.');
        });

        it('should not update parent group value/validity from child until blur', () => {
          const fixture = initTest(FormGroupComp);
          const form = new FormGroup(
              {login: new FormControl('', {validators: Validators.required, updateOn: 'blur'})});
          fixture.componentInstance.form = form;
          fixture.detectChanges();

          const input = fixture.debugElement.query(By.css('input')).nativeElement;
          input.value = 'Nancy';
          dispatchEvent(input, 'input');
          fixture.detectChanges();

          expect(form.value)
              .toEqual({login: ''}, 'Expected group value to remain unchanged until blur.');
          expect(form.valid).toBe(false, 'Expected no validation to occur on group until blur.');

          dispatchEvent(input, 'blur');
          fixture.detectChanges();

          expect(form.value)
              .toEqual({login: 'Nancy'}, 'Expected group value to change once input blurred.');
          expect(form.valid).toBe(true, 'Expected validation to run once input blurred.');
        });

        it('should not wait for blur event to update if value is set programmatically', () => {
          const fixture = initTest(FormControlComp);
          const control = new FormControl('', {validators: Validators.required, updateOn: 'blur'});
          fixture.componentInstance.control = control;
          fixture.detectChanges();

          control.setValue('Nancy');
          fixture.detectChanges();

          const input = fixture.debugElement.query(By.css('input')).nativeElement;
          expect(input.value).toEqual('Nancy', 'Expected value to propagate to view immediately.');
          expect(control.value).toEqual('Nancy', 'Expected model value to update immediately.');
          expect(control.valid).toBe(true, 'Expected validation to run immediately.');
        });

        it('should not update dirty state until control is blurred', () => {
          const fixture = initTest(FormControlComp);
          const control = new FormControl('', {updateOn: 'blur'});
          fixture.componentInstance.control = control;
          fixture.detectChanges();

          expect(control.dirty).toBe(false, 'Expected control to start out pristine.');

          const input = fixture.debugElement.query(By.css('input')).nativeElement;
          input.value = 'Nancy';
          dispatchEvent(input, 'input');
          fixture.detectChanges();

          expect(control.dirty).toBe(false, 'Expected control to stay pristine until blurred.');

          dispatchEvent(input, 'blur');
          fixture.detectChanges();

          expect(control.dirty).toBe(true, 'Expected control to update dirty state when blurred.');
        });

        it('should update touched when control is blurred', () => {
          const fixture = initTest(FormControlComp);
          const control = new FormControl('', {updateOn: 'blur'});
          fixture.componentInstance.control = control;
          fixture.detectChanges();

          expect(control.touched).toBe(false, 'Expected control to start out untouched.');

          const input = fixture.debugElement.query(By.css('input')).nativeElement;
          dispatchEvent(input, 'blur');
          fixture.detectChanges();

          expect(control.touched)
              .toBe(true, 'Expected control to update touched state when blurred.');
        });

        it('should continue waiting for blur to update if previously blurred', () => {
          const fixture = initTest(FormControlComp);
          const control =
              new FormControl('Nancy', {validators: Validators.required, updateOn: 'blur'});
          fixture.componentInstance.control = control;
          fixture.detectChanges();

          const input = fixture.debugElement.query(By.css('input')).nativeElement;
          dispatchEvent(input, 'blur');
          fixture.detectChanges();

          dispatchEvent(input, 'focus');
          input.value = '';
          dispatchEvent(input, 'input');
          fixture.detectChanges();

          expect(control.value)
              .toEqual('Nancy', 'Expected value to remain unchanged until second blur.');
          expect(control.valid).toBe(true, 'Expected validation not to run until second blur.');

          dispatchEvent(input, 'blur');
          fixture.detectChanges();

          expect(control.value).toEqual('', 'Expected value to update when blur occurs again.');
          expect(control.valid).toBe(false, 'Expected validation to run when blur occurs again.');
        });

        it('should not use stale pending value if value set programmatically', () => {
          const fixture = initTest(FormControlComp);
          const control = new FormControl('', {validators: Validators.required, updateOn: 'blur'});
          fixture.componentInstance.control = control;
          fixture.detectChanges();

          const input = fixture.debugElement.query(By.css('input')).nativeElement;
          input.value = 'aa';
          dispatchEvent(input, 'input');
          fixture.detectChanges();

          control.setValue('Nancy');
          fixture.detectChanges();

          dispatchEvent(input, 'blur');
          fixture.detectChanges();

          expect(input.value).toEqual('Nancy', 'Expected programmatic value to stick after blur.');
        });

        it('should set initial value and validity on init', () => {
          const fixture = initTest(FormControlComp);
          const control =
              new FormControl('Nancy', {validators: Validators.maxLength(3), updateOn: 'blur'});
          fixture.componentInstance.control = control;
          fixture.detectChanges();

          const input = fixture.debugElement.query(By.css('input')).nativeElement;

          expect(input.value).toEqual('Nancy', 'Expected value to be set in the view.');
          expect(control.value).toEqual('Nancy', 'Expected initial model value to be set.');
          expect(control.valid).toBe(false, 'Expected validation to run on initial value.');
        });

        it('should reset properly', () => {
          const fixture = initTest(FormControlComp);
          const control = new FormControl('', {validators: Validators.required, updateOn: 'blur'});
          fixture.componentInstance.control = control;
          fixture.detectChanges();

          const input = fixture.debugElement.query(By.css('input')).nativeElement;
          input.value = 'aa';
          dispatchEvent(input, 'input');
          fixture.detectChanges();

          dispatchEvent(input, 'blur');
          fixture.detectChanges();
          expect(control.dirty).toBe(true, 'Expected control to be dirty on blur.');

          control.reset();

          dispatchEvent(input, 'blur');
          fixture.detectChanges();

          expect(input.value).toEqual('', 'Expected view value to reset');
          expect(control.value).toBe(null, 'Expected pending value to reset.');
          expect(control.dirty).toBe(false, 'Expected pending dirty value to reset.');
        });

        it('should be able to remove a control as a result of another control being reset', () => {
          @Component({
            template: `
              <form [formGroup]="form">
                <input formControlName="name">
                <input formControlName="surname">
              </form>
            `
          })
          class App implements OnDestroy {
            private _subscription: Subscription;

            form = new FormGroup({
              name: new FormControl('Frodo'),
              surname: new FormControl('Baggins'),
            });

            constructor() {
              this._subscription = this.form.controls.name.valueChanges.subscribe(value => {
                if (!value) {
                  this.form.removeControl('surname');
                }
              });
            }

            ngOnDestroy() {
              this._subscription.unsubscribe();
            }
          }

          const fixture = initTest(App);
          fixture.detectChanges();
          expect(fixture.componentInstance.form.value).toEqual({name: 'Frodo', surname: 'Baggins'});

          expect(() => {
            fixture.componentInstance.form.reset();
            fixture.detectChanges();
          }).not.toThrow();

          expect(fixture.componentInstance.form.value).toEqual({name: null});
        });

        it('should not emit valueChanges or statusChanges until blur', () => {
          const fixture = initTest(FormControlComp);
          const control = new FormControl('', {validators: Validators.required, updateOn: 'blur'});
          fixture.componentInstance.control = control;
          fixture.detectChanges();
          const values: string[] = [];

          const sub =
              merge(control.valueChanges, control.statusChanges).subscribe(val => values.push(val));

          const input = fixture.debugElement.query(By.css('input')).nativeElement;
          input.value = 'Nancy';
          dispatchEvent(input, 'input');
          fixture.detectChanges();

          expect(values).toEqual([], 'Expected no valueChanges or statusChanges on input.');

          dispatchEvent(input, 'blur');
          fixture.detectChanges();

          expect(values).toEqual(
              ['Nancy', 'VALID'], 'Expected valueChanges and statusChanges on blur.');

          sub.unsubscribe();
        });

        it('should not emit valueChanges or statusChanges on blur if value unchanged', () => {
          const fixture = initTest(FormControlComp);
          const control = new FormControl('', {validators: Validators.required, updateOn: 'blur'});
          fixture.componentInstance.control = control;
          fixture.detectChanges();
          const values: string[] = [];

          const sub =
              merge(control.valueChanges, control.statusChanges).subscribe(val => values.push(val));

          const input = fixture.debugElement.query(By.css('input')).nativeElement;
          dispatchEvent(input, 'blur');
          fixture.detectChanges();
          expect(values).toEqual(
              [], 'Expected no valueChanges or statusChanges if value unchanged.');

          input.value = 'Nancy';
          dispatchEvent(input, 'input');
          fixture.detectChanges();
          expect(values).toEqual([], 'Expected no valueChanges or statusChanges on input.');

          dispatchEvent(input, 'blur');
          fixture.detectChanges();
          expect(values).toEqual(
              ['Nancy', 'VALID'],
              'Expected valueChanges and statusChanges on blur if value changed.');

          dispatchEvent(input, 'blur');
          fixture.detectChanges();
          expect(values).toEqual(
              ['Nancy', 'VALID'],
              'Expected valueChanges and statusChanges not to fire again on blur unless value changed.');

          input.value = 'Bess';
          dispatchEvent(input, 'input');
          fixture.detectChanges();
          expect(values).toEqual(
              ['Nancy', 'VALID'],
              'Expected valueChanges and statusChanges not to fire on input after blur.');

          dispatchEvent(input, 'blur');
          fixture.detectChanges();
          expect(values).toEqual(
              ['Nancy', 'VALID', 'Bess', 'VALID'],
              'Expected valueChanges and statusChanges to fire again on blur if value changed.');

          sub.unsubscribe();
        });

        it('should mark as pristine properly if pending dirty', () => {
          const fixture = initTest(FormControlComp);
          const control = new FormControl('', {updateOn: 'blur'});
          fixture.componentInstance.control = control;
          fixture.detectChanges();

          const input = fixture.debugElement.query(By.css('input')).nativeElement;
          input.value = 'aa';
          dispatchEvent(input, 'input');
          fixture.detectChanges();

          dispatchEvent(input, 'blur');
          fixture.detectChanges();

          control.markAsPristine();
          expect(control.dirty).toBe(false, 'Expected control to become pristine.');

          dispatchEvent(input, 'blur');
          fixture.detectChanges();

          expect(control.dirty).toBe(false, 'Expected pending dirty value to reset.');
        });

        it('should update on blur with group updateOn', () => {
          const fixture = initTest(FormGroupComp);
          const control = new FormControl('', Validators.required);
          const formGroup = new FormGroup({login: control}, {updateOn: 'blur'});
          fixture.componentInstance.form = formGroup;
          fixture.detectChanges();

          const input = fixture.debugElement.query(By.css('input')).nativeElement;
          input.value = 'Nancy';
          dispatchEvent(input, 'input');
          fixture.detectChanges();

          expect(control.value).toEqual('', 'Expected value to remain unchanged until blur.');
          expect(control.valid).toBe(false, 'Expected no validation to occur until blur.');

          dispatchEvent(input, 'blur');
          fixture.detectChanges();

          expect(control.value)
              .toEqual('Nancy', 'Expected value to change once control is blurred.');
          expect(control.valid).toBe(true, 'Expected validation to run once control is blurred.');
        });

        it('should update on blur with array updateOn', () => {
          const fixture = initTest(FormArrayComp);
          const control = new FormControl('', Validators.required);
          const cityArray = new FormArray([control], {updateOn: 'blur'});
          const formGroup = new FormGroup({cities: cityArray});
          fixture.componentInstance.form = formGroup;
          fixture.componentInstance.cityArray = cityArray;
          fixture.detectChanges();

          const input = fixture.debugElement.query(By.css('input')).nativeElement;
          input.value = 'Nancy';
          dispatchEvent(input, 'input');
          fixture.detectChanges();

          expect(control.value).toEqual('', 'Expected value to remain unchanged until blur.');
          expect(control.valid).toBe(false, 'Expected no validation to occur until blur.');

          dispatchEvent(input, 'blur');
          fixture.detectChanges();

          expect(control.value)
              .toEqual('Nancy', 'Expected value to change once control is blurred.');
          expect(control.valid).toBe(true, 'Expected validation to run once control is blurred.');
        });


        it('should allow child control updateOn blur to override group updateOn', () => {
          const fixture = initTest(NestedFormGroupComp);
          const loginControl =
              new FormControl('', {validators: Validators.required, updateOn: 'change'});
          const passwordControl = new FormControl('', Validators.required);
          const formGroup = new FormGroup(
              {signin: new FormGroup({login: loginControl, password: passwordControl})},
              {updateOn: 'blur'});
          fixture.componentInstance.form = formGroup;
          fixture.detectChanges();

          const [loginInput, passwordInput] = fixture.debugElement.queryAll(By.css('input'));
          loginInput.nativeElement.value = 'Nancy';
          dispatchEvent(loginInput.nativeElement, 'input');
          fixture.detectChanges();

          expect(loginControl.value).toEqual('Nancy', 'Expected value change on input.');
          expect(loginControl.valid).toBe(true, 'Expected validation to run on input.');

          passwordInput.nativeElement.value = 'Carson';
          dispatchEvent(passwordInput.nativeElement, 'input');
          fixture.detectChanges();

          expect(passwordControl.value)
              .toEqual('', 'Expected value to remain unchanged until blur.');
          expect(passwordControl.valid).toBe(false, 'Expected no validation to occur until blur.');

          dispatchEvent(passwordInput.nativeElement, 'blur');
          fixture.detectChanges();

          expect(passwordControl.value)
              .toEqual('Carson', 'Expected value to change once control is blurred.');
          expect(passwordControl.valid)
              .toBe(true, 'Expected validation to run once control is blurred.');
        });
      });

      describe('on submit', () => {
        it('should set initial value and validity on init', () => {
          const fixture = initTest(FormGroupComp);
          const form = new FormGroup({
            login: new FormControl('Nancy', {validators: Validators.required, updateOn: 'submit'})
          });
          fixture.componentInstance.form = form;
          fixture.detectChanges();

          const input = fixture.debugElement.query(By.css('input')).nativeElement;
          expect(input.value).toEqual('Nancy', 'Expected initial value to propagate to view.');
          expect(form.value).toEqual({login: 'Nancy'}, 'Expected initial value to be set.');
          expect(form.valid).toBe(true, 'Expected form to run validation on initial value.');
        });

        it('should not update value or validity until submit', () => {
          const fixture = initTest(FormGroupComp);
          const formGroup = new FormGroup(
              {login: new FormControl('', {validators: Validators.required, updateOn: 'submit'})});
          fixture.componentInstance.form = formGroup;
          fixture.detectChanges();

          const input = fixture.debugElement.query(By.css('input')).nativeElement;
          input.value = 'Nancy';
          dispatchEvent(input, 'input');
          fixture.detectChanges();

          expect(formGroup.value)
              .toEqual({login: ''}, 'Expected form value to remain unchanged on input.');
          expect(formGroup.valid).toBe(false, 'Expected form validation not to run on input.');

          dispatchEvent(input, 'blur');
          fixture.detectChanges();

          expect(formGroup.value)
              .toEqual({login: ''}, 'Expected form value to remain unchanged on blur.');
          expect(formGroup.valid).toBe(false, 'Expected form validation not to run on blur.');

          const form = fixture.debugElement.query(By.css('form')).nativeElement;
          dispatchEvent(form, 'submit');
          fixture.detectChanges();

          expect(formGroup.value)
              .toEqual({login: 'Nancy'}, 'Expected form value to update on submit.');
          expect(formGroup.valid).toBe(true, 'Expected form validation to run on submit.');
        });

        it('should not update after submit until a second submit', () => {
          const fixture = initTest(FormGroupComp);
          const formGroup = new FormGroup(
              {login: new FormControl('', {validators: Validators.required, updateOn: 'submit'})});
          fixture.componentInstance.form = formGroup;
          fixture.detectChanges();

          const input = fixture.debugElement.query(By.css('input')).nativeElement;
          input.value = 'Nancy';
          dispatchEvent(input, 'input');
          fixture.detectChanges();

          const form = fixture.debugElement.query(By.css('form')).nativeElement;
          dispatchEvent(form, 'submit');
          fixture.detectChanges();

          input.value = '';
          dispatchEvent(input, 'input');
          fixture.detectChanges();

          expect(formGroup.value)
              .toEqual({login: 'Nancy'}, 'Expected value not to change until a second submit.');
          expect(formGroup.valid)
              .toBe(true, 'Expected validation not to run until a second submit.');

          dispatchEvent(form, 'submit');
          fixture.detectChanges();

          expect(formGroup.value)
              .toEqual({login: ''}, 'Expected value to update on the second submit.');
          expect(formGroup.valid).toBe(false, 'Expected validation to run on a second submit.');
        });

        it('should not wait for submit to set value programmatically', () => {
          const fixture = initTest(FormGroupComp);
          const formGroup = new FormGroup(
              {login: new FormControl('', {validators: Validators.required, updateOn: 'submit'})});
          fixture.componentInstance.form = formGroup;
          fixture.detectChanges();

          formGroup.setValue({login: 'Nancy'});
          fixture.detectChanges();

          const input = fixture.debugElement.query(By.css('input')).nativeElement;
          expect(input.value).toEqual('Nancy', 'Expected view value to update immediately.');
          expect(formGroup.value)
              .toEqual({login: 'Nancy'}, 'Expected form value to update immediately.');
          expect(formGroup.valid).toBe(true, 'Expected form validation to run immediately.');
        });

        it('should not update dirty until submit', () => {
          const fixture = initTest(FormGroupComp);
          const formGroup = new FormGroup({login: new FormControl('', {updateOn: 'submit'})});
          fixture.componentInstance.form = formGroup;
          fixture.detectChanges();

          const input = fixture.debugElement.query(By.css('input')).nativeElement;
          dispatchEvent(input, 'input');
          fixture.detectChanges();

          expect(formGroup.dirty).toBe(false, 'Expected dirty not to change on input.');

          dispatchEvent(input, 'blur');
          fixture.detectChanges();

          expect(formGroup.dirty).toBe(false, 'Expected dirty not to change on blur.');

          const form = fixture.debugElement.query(By.css('form')).nativeElement;
          dispatchEvent(form, 'submit');
          fixture.detectChanges();

          expect(formGroup.dirty).toBe(true, 'Expected dirty to update on submit.');
        });

        it('should not update touched until submit', () => {
          const fixture = initTest(FormGroupComp);
          const formGroup = new FormGroup({login: new FormControl('', {updateOn: 'submit'})});
          fixture.componentInstance.form = formGroup;
          fixture.detectChanges();

          const input = fixture.debugElement.query(By.css('input')).nativeElement;
          dispatchEvent(input, 'blur');
          fixture.detectChanges();

          expect(formGroup.touched).toBe(false, 'Expected touched not to change until submit.');

          const form = fixture.debugElement.query(By.css('form')).nativeElement;
          dispatchEvent(form, 'submit');
          fixture.detectChanges();

          expect(formGroup.touched).toBe(true, 'Expected touched to update on submit.');
        });

        it('should reset properly', () => {
          const fixture = initTest(FormGroupComp);
          const formGroup = new FormGroup(
              {login: new FormControl('', {validators: Validators.required, updateOn: 'submit'})});
          fixture.componentInstance.form = formGroup;
          fixture.detectChanges();

          const input = fixture.debugElement.query(By.css('input')).nativeElement;
          input.value = 'Nancy';
          dispatchEvent(input, 'input');
          fixture.detectChanges();

          dispatchEvent(input, 'blur');
          fixture.detectChanges();

          formGroup.reset();
          fixture.detectChanges();

          expect(input.value).toEqual('', 'Expected view value to reset.');
          expect(formGroup.value).toEqual({login: null}, 'Expected form value to reset');
          expect(formGroup.dirty).toBe(false, 'Expected dirty to stay false on reset.');
          expect(formGroup.touched).toBe(false, 'Expected touched to stay false on reset.');

          const form = fixture.debugElement.query(By.css('form')).nativeElement;
          dispatchEvent(form, 'submit');
          fixture.detectChanges();

          expect(formGroup.value)
              .toEqual({login: null}, 'Expected form value to stay empty on submit');
          expect(formGroup.dirty).toBe(false, 'Expected dirty to stay false on submit.');
          expect(formGroup.touched).toBe(false, 'Expected touched to stay false on submit.');
        });

        it('should not emit valueChanges or statusChanges until submit', () => {
          const fixture = initTest(FormGroupComp);
          const control =
              new FormControl('', {validators: Validators.required, updateOn: 'submit'});
          const formGroup = new FormGroup({login: control});
          fixture.componentInstance.form = formGroup;
          fixture.detectChanges();

          const values: any[] = [];
          const streams = merge(
              control.valueChanges, control.statusChanges, formGroup.valueChanges,
              formGroup.statusChanges);
          const sub = streams.subscribe(val => values.push(val));

          const input = fixture.debugElement.query(By.css('input')).nativeElement;
          input.value = 'Nancy';
          dispatchEvent(input, 'input');
          fixture.detectChanges();

          expect(values).toEqual([], 'Expected no valueChanges or statusChanges on input');

          dispatchEvent(input, 'blur');
          fixture.detectChanges();

          expect(values).toEqual([], 'Expected no valueChanges or statusChanges on blur');

          const form = fixture.debugElement.query(By.css('form')).nativeElement;
          dispatchEvent(form, 'submit');
          fixture.detectChanges();

          expect(values).toEqual(
              ['Nancy', 'VALID', {login: 'Nancy'}, 'VALID'],
              'Expected valueChanges and statusChanges to update on submit.');

          sub.unsubscribe();
        });

        it('should not emit valueChanges or statusChanges on submit if value unchanged', () => {
          const fixture = initTest(FormGroupComp);
          const control =
              new FormControl('', {validators: Validators.required, updateOn: 'submit'});
          const formGroup = new FormGroup({login: control});
          fixture.componentInstance.form = formGroup;
          fixture.detectChanges();

          const values: (string|{[key: string]: string})[] = [];
          const streams = merge(
              control.valueChanges, control.statusChanges, formGroup.valueChanges,
              formGroup.statusChanges);
          const sub = streams.subscribe(val => values.push(val));

          const form = fixture.debugElement.query(By.css('form')).nativeElement;
          dispatchEvent(form, 'submit');
          fixture.detectChanges();
          expect(values).toEqual(
              [], 'Expected no valueChanges or statusChanges if value unchanged.');

          const input = fixture.debugElement.query(By.css('input')).nativeElement;
          input.value = 'Nancy';
          dispatchEvent(input, 'input');
          fixture.detectChanges();
          expect(values).toEqual([], 'Expected no valueChanges or statusChanges on input.');

          dispatchEvent(form, 'submit');
          fixture.detectChanges();
          expect(values).toEqual(
              ['Nancy', 'VALID', {login: 'Nancy'}, 'VALID'],
              'Expected valueChanges and statusChanges on submit if value changed.');

          dispatchEvent(form, 'submit');
          fixture.detectChanges();
          expect(values).toEqual(
              ['Nancy', 'VALID', {login: 'Nancy'}, 'VALID'],
              'Expected valueChanges and statusChanges not to fire again if value unchanged.');

          input.value = 'Bess';
          dispatchEvent(input, 'input');
          fixture.detectChanges();

          expect(values).toEqual(
              ['Nancy', 'VALID', {login: 'Nancy'}, 'VALID'],
              'Expected valueChanges and statusChanges not to fire on input after submit.');

          dispatchEvent(form, 'submit');
          fixture.detectChanges();

          expect(values).toEqual(
              [
                'Nancy', 'VALID', {login: 'Nancy'}, 'VALID', 'Bess', 'VALID', {login: 'Bess'},
                'VALID'
              ],
              'Expected valueChanges and statusChanges to fire again on submit if value changed.');

          sub.unsubscribe();
        });

        it('should not run validation for onChange controls on submit', () => {
          const validatorSpy = jasmine.createSpy('validator');
          const groupValidatorSpy = jasmine.createSpy('groupValidatorSpy');

          const fixture = initTest(NestedFormGroupComp);
          const formGroup = new FormGroup({
            signin: new FormGroup({login: new FormControl(), password: new FormControl()}),
            email: new FormControl('', {updateOn: 'submit'})
          });
          fixture.componentInstance.form = formGroup;
          fixture.detectChanges();

          formGroup.get('signin.login')!.setValidators(validatorSpy);
          formGroup.get('signin')!.setValidators(groupValidatorSpy);

          const form = fixture.debugElement.query(By.css('form')).nativeElement;
          dispatchEvent(form, 'submit');
          fixture.detectChanges();

          expect(validatorSpy).not.toHaveBeenCalled();
          expect(groupValidatorSpy).not.toHaveBeenCalled();
        });

        it('should mark as untouched properly if pending touched', () => {
          const fixture = initTest(FormGroupComp);
          const formGroup = new FormGroup({login: new FormControl('', {updateOn: 'submit'})});
          fixture.componentInstance.form = formGroup;
          fixture.detectChanges();

          const input = fixture.debugElement.query(By.css('input')).nativeElement;
          dispatchEvent(input, 'blur');
          fixture.detectChanges();

          formGroup.markAsUntouched();
          fixture.detectChanges();

          expect(formGroup.touched).toBe(false, 'Expected group to become untouched.');

          const form = fixture.debugElement.query(By.css('form')).nativeElement;
          dispatchEvent(form, 'submit');
          fixture.detectChanges();

          expect(formGroup.touched).toBe(false, 'Expected touched to stay false on submit.');
        });

        it('should update on submit with group updateOn', () => {
          const fixture = initTest(FormGroupComp);
          const control = new FormControl('', Validators.required);
          const formGroup = new FormGroup({login: control}, {updateOn: 'submit'});
          fixture.componentInstance.form = formGroup;
          fixture.detectChanges();

          const input = fixture.debugElement.query(By.css('input')).nativeElement;
          input.value = 'Nancy';
          dispatchEvent(input, 'input');
          fixture.detectChanges();

          expect(control.value).toEqual('', 'Expected value to remain unchanged until submit.');
          expect(control.valid).toBe(false, 'Expected no validation to occur until submit.');

          dispatchEvent(input, 'blur');
          fixture.detectChanges();

          expect(control.value).toEqual('', 'Expected value to remain unchanged until submit.');
          expect(control.valid).toBe(false, 'Expected no validation to occur until submit.');

          const form = fixture.debugElement.query(By.css('form')).nativeElement;
          dispatchEvent(form, 'submit');
          fixture.detectChanges();

          expect(control.value).toEqual('Nancy', 'Expected value to change on submit.');
          expect(control.valid).toBe(true, 'Expected validation to run on submit.');
        });

        it('should update on submit with array updateOn', () => {
          const fixture = initTest(FormArrayComp);
          const control = new FormControl('', Validators.required);
          const cityArray = new FormArray([control], {updateOn: 'submit'});
          const formGroup = new FormGroup({cities: cityArray});
          fixture.componentInstance.form = formGroup;
          fixture.componentInstance.cityArray = cityArray;
          fixture.detectChanges();

          const input = fixture.debugElement.query(By.css('input')).nativeElement;
          input.value = 'Nancy';
          dispatchEvent(input, 'input');
          fixture.detectChanges();

          expect(control.value).toEqual('', 'Expected value to remain unchanged until submit.');
          expect(control.valid).toBe(false, 'Expected no validation to occur until submit.');


          const form = fixture.debugElement.query(By.css('form')).nativeElement;
          dispatchEvent(form, 'submit');
          fixture.detectChanges();

          expect(control.value).toEqual('Nancy', 'Expected value to change once control on submit');
          expect(control.valid).toBe(true, 'Expected validation to run on submit.');
        });

        it('should allow child control updateOn submit to override group updateOn', () => {
          const fixture = initTest(NestedFormGroupComp);
          const loginControl =
              new FormControl('', {validators: Validators.required, updateOn: 'change'});
          const passwordControl = new FormControl('', Validators.required);
          const formGroup = new FormGroup(
              {signin: new FormGroup({login: loginControl, password: passwordControl})},
              {updateOn: 'submit'});
          fixture.componentInstance.form = formGroup;
          fixture.detectChanges();

          const [loginInput, passwordInput] = fixture.debugElement.queryAll(By.css('input'));
          loginInput.nativeElement.value = 'Nancy';
          dispatchEvent(loginInput.nativeElement, 'input');
          fixture.detectChanges();

          expect(loginControl.value).toEqual('Nancy', 'Expected value change on input.');
          expect(loginControl.valid).toBe(true, 'Expected validation to run on input.');

          passwordInput.nativeElement.value = 'Carson';
          dispatchEvent(passwordInput.nativeElement, 'input');
          fixture.detectChanges();

          expect(passwordControl.value)
              .toEqual('', 'Expected value to remain unchanged until submit.');
          expect(passwordControl.valid)
              .toBe(false, 'Expected no validation to occur until submit.');

          const form = fixture.debugElement.query(By.css('form')).nativeElement;
          dispatchEvent(form, 'submit');
          fixture.detectChanges();

          expect(passwordControl.value).toEqual('Carson', 'Expected value to change on submit.');
          expect(passwordControl.valid).toBe(true, 'Expected validation to run on submit.');
        });
      });
    });

    describe('ngModel interactions', () => {
      let warnSpy: jasmine.Spy;

      beforeEach(() => {
        // Reset `_ngModelWarningSentOnce` on `FormControlDirective` and `FormControlName` types.
        (FormControlDirective as any)._ngModelWarningSentOnce = false;
        (FormControlName as any)._ngModelWarningSentOnce = false;

        warnSpy = spyOn(console, 'warn');
      });

      describe('deprecation warnings', () => {
        it('should warn once by default when using ngModel with formControlName', fakeAsync(() => {
             const fixture = initTest(FormGroupNgModel);
             fixture.componentInstance.form =
                 new FormGroup({'login': new FormControl(''), 'password': new FormControl('')});
             fixture.detectChanges();
             tick();

             expect(warnSpy.calls.count()).toEqual(1);
             expect(warnSpy.calls.mostRecent().args[0])
                 .toMatch(
                     /It looks like you're using ngModel on the same form field as formControlName/gi);

             fixture.componentInstance.login = 'some value';
             fixture.detectChanges();
             tick();

             expect(warnSpy.calls.count()).toEqual(1);
           }));

        it('should warn once by default when using ngModel with formControl', fakeAsync(() => {
             const fixture = initTest(FormControlNgModel);
             fixture.componentInstance.control = new FormControl('');
             fixture.componentInstance.passwordControl = new FormControl('');
             fixture.detectChanges();
             tick();

             expect(warnSpy.calls.count()).toEqual(1);
             expect(warnSpy.calls.mostRecent().args[0])
                 .toMatch(
                     /It looks like you're using ngModel on the same form field as formControl/gi);

             fixture.componentInstance.login = 'some value';
             fixture.detectChanges();
             tick();

             expect(warnSpy.calls.count()).toEqual(1);
           }));

        it('should warn once for each instance when global provider is provided with "always"',
           fakeAsync(() => {
             TestBed.configureTestingModule({
               declarations: [FormControlNgModel],
               imports: [ReactiveFormsModule.withConfig({warnOnNgModelWithFormControl: 'always'})]
             });

             const fixture = TestBed.createComponent(FormControlNgModel);
             fixture.componentInstance.control = new FormControl('');
             fixture.componentInstance.passwordControl = new FormControl('');
             fixture.detectChanges();
             tick();

             expect(warnSpy.calls.count()).toEqual(2);
             expect(warnSpy.calls.mostRecent().args[0])
                 .toMatch(
                     /It looks like you're using ngModel on the same form field as formControl/gi);
           }));

        it('should silence warnings when global provider is provided with "never"',
           fakeAsync(() => {
             TestBed.configureTestingModule({
               declarations: [FormControlNgModel],
               imports: [ReactiveFormsModule.withConfig({warnOnNgModelWithFormControl: 'never'})]
             });

             const fixture = TestBed.createComponent(FormControlNgModel);
             fixture.componentInstance.control = new FormControl('');
             fixture.componentInstance.passwordControl = new FormControl('');
             fixture.detectChanges();
             tick();

             expect(warnSpy).not.toHaveBeenCalled();
           }));
      });

      it('should support ngModel for complex forms', fakeAsync(() => {
           const fixture = initTest(FormGroupNgModel);
           fixture.componentInstance.form =
               new FormGroup({'login': new FormControl(''), 'password': new FormControl('')});
           fixture.componentInstance.login = 'oldValue';
           fixture.detectChanges();
           tick();

           const input = fixture.debugElement.query(By.css('input')).nativeElement;
           expect(input.value).toEqual('oldValue');

           input.value = 'updatedValue';
           dispatchEvent(input, 'input');

           tick();
           expect(fixture.componentInstance.login).toEqual('updatedValue');
         }));

      it('should support ngModel for single fields', fakeAsync(() => {
           const fixture = initTest(FormControlNgModel);
           fixture.componentInstance.control = new FormControl('');
           fixture.componentInstance.passwordControl = new FormControl('');
           fixture.componentInstance.login = 'oldValue';
           fixture.detectChanges();
           tick();

           const input = fixture.debugElement.query(By.css('input')).nativeElement;
           expect(input.value).toEqual('oldValue');

           input.value = 'updatedValue';
           dispatchEvent(input, 'input');
           tick();

           expect(fixture.componentInstance.login).toEqual('updatedValue');
         }));

      it('should not update the view when the value initially came from the view', fakeAsync(() => {
           if (isNode) return;
           const fixture = initTest(FormControlNgModel);
           fixture.componentInstance.control = new FormControl('');
           fixture.componentInstance.passwordControl = new FormControl('');
           fixture.detectChanges();
           tick();

           const input = fixture.debugElement.query(By.css('input')).nativeElement;
           input.value = 'aa';
           input.setSelectionRange(1, 2);
           dispatchEvent(input, 'input');

           fixture.detectChanges();
           tick();

           // selection start has not changed because we did not reset the value
           expect(input.selectionStart).toEqual(1);
         }));

      it('should work with updateOn submit', fakeAsync(() => {
           const fixture = initTest(FormGroupNgModel);
           const formGroup = new FormGroup(
               {login: new FormControl('', {updateOn: 'submit'}), password: new FormControl('')});
           fixture.componentInstance.form = formGroup;
           fixture.componentInstance.login = 'initial';
           fixture.detectChanges();
           tick();

           const input = fixture.debugElement.query(By.css('input')).nativeElement;
           input.value = 'Nancy';
           dispatchEvent(input, 'input');
           fixture.detectChanges();
           tick();

           expect(fixture.componentInstance.login)
               .toEqual('initial', 'Expected ngModel value to remain unchanged on input.');

           const form = fixture.debugElement.query(By.css('form')).nativeElement;
           dispatchEvent(form, 'submit');
           fixture.detectChanges();
           tick();

           expect(fixture.componentInstance.login)
               .toEqual('Nancy', 'Expected ngModel value to update on submit.');
         }));
    });

    describe('validations', () => {
      it('required validator should validate checkbox', () => {
        const fixture = initTest(FormControlCheckboxRequiredValidator);
        const control = new FormControl(false, Validators.requiredTrue);
        fixture.componentInstance.control = control;
        fixture.detectChanges();

        const checkbox = fixture.debugElement.query(By.css('input'));
        expect(checkbox.nativeElement.checked).toBe(false);
        expect(control.hasError('required')).toEqual(true);

        checkbox.nativeElement.checked = true;
        dispatchEvent(checkbox.nativeElement, 'change');
        fixture.detectChanges();

        expect(checkbox.nativeElement.checked).toBe(true);
        expect(control.hasError('required')).toEqual(false);
      });

      // Note: this scenario goes against validator function rules were `null` is the only
      // representation of a successful check. However the `Validators.combine` has a side-effect
      // where falsy values are treated as success and `null` is returned from the wrapper function.
      // The goal of this test is to prevent regressions for validators that return falsy values by
      // mistake and rely on the `Validators.compose` side-effects to normalize the value to `null`
      // instead.
      it('should treat validators that return `undefined` as successful', () => {
        const fixture = initTest(FormControlComp);
        const validatorFn = (control: AbstractControl) => control.value ?? undefined;
        const control = new FormControl(undefined, validatorFn);
        fixture.componentInstance.control = control;
        fixture.detectChanges();

        expect(control.status).toBe('VALID');
        expect(control.errors).toBe(null);
      });

      it('should use sync validators defined in html', () => {
        const fixture = initTest(LoginIsEmptyWrapper, LoginIsEmptyValidator);
        const form = new FormGroup({
          'login': new FormControl(''),
          'min': new FormControl(''),
          'max': new FormControl(''),
          'pattern': new FormControl('')
        });
        fixture.componentInstance.form = form;
        fixture.detectChanges();

        const required = fixture.debugElement.query(By.css('[required]'));
        const minLength = fixture.debugElement.query(By.css('[minlength]'));
        const maxLength = fixture.debugElement.query(By.css('[maxlength]'));
        const pattern = fixture.debugElement.query(By.css('[pattern]'));

        required.nativeElement.value = '';
        minLength.nativeElement.value = '1';
        maxLength.nativeElement.value = '1234';
        pattern.nativeElement.value = '12';

        dispatchEvent(required.nativeElement, 'input');
        dispatchEvent(minLength.nativeElement, 'input');
        dispatchEvent(maxLength.nativeElement, 'input');
        dispatchEvent(pattern.nativeElement, 'input');

        expect(form.hasError('required', ['login'])).toEqual(true);
        expect(form.hasError('minlength', ['min'])).toEqual(true);
        expect(form.hasError('maxlength', ['max'])).toEqual(true);
        expect(form.hasError('pattern', ['pattern'])).toEqual(true);
        expect(form.hasError('loginIsEmpty')).toEqual(true);

        required.nativeElement.value = '1';
        minLength.nativeElement.value = '123';
        maxLength.nativeElement.value = '123';
        pattern.nativeElement.value = '123';

        dispatchEvent(required.nativeElement, 'input');
        dispatchEvent(minLength.nativeElement, 'input');
        dispatchEvent(maxLength.nativeElement, 'input');
        dispatchEvent(pattern.nativeElement, 'input');

        expect(form.valid).toEqual(true);
      });

      it('should use sync validators using bindings', () => {
        const fixture = initTest(ValidationBindingsForm);
        const form = new FormGroup({
          'login': new FormControl(''),
          'min': new FormControl(''),
          'max': new FormControl(''),
          'pattern': new FormControl('')
        });
        fixture.componentInstance.form = form;
        fixture.componentInstance.required = true;
        fixture.componentInstance.minLen = 3;
        fixture.componentInstance.maxLen = 3;
        fixture.componentInstance.pattern = '.{3,}';
        fixture.detectChanges();

        const required = fixture.debugElement.query(By.css('[name=required]'));
        const minLength = fixture.debugElement.query(By.css('[name=minlength]'));
        const maxLength = fixture.debugElement.query(By.css('[name=maxlength]'));
        const pattern = fixture.debugElement.query(By.css('[name=pattern]'));

        required.nativeElement.value = '';
        minLength.nativeElement.value = '1';
        maxLength.nativeElement.value = '1234';
        pattern.nativeElement.value = '12';

        dispatchEvent(required.nativeElement, 'input');
        dispatchEvent(minLength.nativeElement, 'input');
        dispatchEvent(maxLength.nativeElement, 'input');
        dispatchEvent(pattern.nativeElement, 'input');

        expect(form.hasError('required', ['login'])).toEqual(true);
        expect(form.hasError('minlength', ['min'])).toEqual(true);
        expect(form.hasError('maxlength', ['max'])).toEqual(true);
        expect(form.hasError('pattern', ['pattern'])).toEqual(true);

        required.nativeElement.value = '1';
        minLength.nativeElement.value = '123';
        maxLength.nativeElement.value = '123';
        pattern.nativeElement.value = '123';

        dispatchEvent(required.nativeElement, 'input');
        dispatchEvent(minLength.nativeElement, 'input');
        dispatchEvent(maxLength.nativeElement, 'input');
        dispatchEvent(pattern.nativeElement, 'input');

        expect(form.valid).toEqual(true);
      });

      it('changes on bound properties should change the validation state of the form', () => {
        const fixture = initTest(ValidationBindingsForm);
        const form = new FormGroup({
          'login': new FormControl(''),
          'min': new FormControl(''),
          'max': new FormControl(''),
          'pattern': new FormControl('')
        });
        fixture.componentInstance.form = form;
        fixture.detectChanges();

        const required = fixture.debugElement.query(By.css('[name=required]'));
        const minLength = fixture.debugElement.query(By.css('[name=minlength]'));
        const maxLength = fixture.debugElement.query(By.css('[name=maxlength]'));
        const pattern = fixture.debugElement.query(By.css('[name=pattern]'));

        required.nativeElement.value = '';
        minLength.nativeElement.value = '1';
        maxLength.nativeElement.value = '1234';
        pattern.nativeElement.value = '12';

        dispatchEvent(required.nativeElement, 'input');
        dispatchEvent(minLength.nativeElement, 'input');
        dispatchEvent(maxLength.nativeElement, 'input');
        dispatchEvent(pattern.nativeElement, 'input');

        expect(form.hasError('required', ['login'])).toEqual(false);
        expect(form.hasError('minlength', ['min'])).toEqual(false);
        expect(form.hasError('maxlength', ['max'])).toEqual(false);
        expect(form.hasError('pattern', ['pattern'])).toEqual(false);
        expect(form.valid).toEqual(true);

        fixture.componentInstance.required = true;
        fixture.componentInstance.minLen = 3;
        fixture.componentInstance.maxLen = 3;
        fixture.componentInstance.pattern = '.{3,}';
        fixture.detectChanges();

        dispatchEvent(required.nativeElement, 'input');
        dispatchEvent(minLength.nativeElement, 'input');
        dispatchEvent(maxLength.nativeElement, 'input');
        dispatchEvent(pattern.nativeElement, 'input');

        expect(form.hasError('required', ['login'])).toEqual(true);
        expect(form.hasError('minlength', ['min'])).toEqual(true);
        expect(form.hasError('maxlength', ['max'])).toEqual(true);
        expect(form.hasError('pattern', ['pattern'])).toEqual(true);
        expect(form.valid).toEqual(false);

        expect(required.nativeElement.getAttribute('required')).toEqual('');
        expect(fixture.componentInstance.minLen.toString())
            .toEqual(minLength.nativeElement.getAttribute('minlength'));
        expect(fixture.componentInstance.maxLen.toString())
            .toEqual(maxLength.nativeElement.getAttribute('maxlength'));
        expect(fixture.componentInstance.pattern.toString())
            .toEqual(pattern.nativeElement.getAttribute('pattern'));

        fixture.componentInstance.required = false;
        fixture.componentInstance.minLen = null!;
        fixture.componentInstance.maxLen = null!;
        fixture.componentInstance.pattern = null!;
        fixture.detectChanges();

        expect(form.hasError('required', ['login'])).toEqual(false);
        expect(form.hasError('minlength', ['min'])).toEqual(false);
        expect(form.hasError('maxlength', ['max'])).toEqual(false);
        expect(form.hasError('pattern', ['pattern'])).toEqual(false);
        expect(form.valid).toEqual(true);

        expect(required.nativeElement.getAttribute('required')).toEqual(null);
        expect(required.nativeElement.getAttribute('minlength')).toEqual(null);
        expect(required.nativeElement.getAttribute('maxlength')).toEqual(null);
        expect(required.nativeElement.getAttribute('pattern')).toEqual(null);
      });

      it('should support rebound controls with rebound validators', () => {
        const fixture = initTest(ValidationBindingsForm);
        const form = new FormGroup({
          'login': new FormControl(''),
          'min': new FormControl(''),
          'max': new FormControl(''),
          'pattern': new FormControl('')
        });
        fixture.componentInstance.form = form;
        fixture.componentInstance.required = true;
        fixture.componentInstance.minLen = 3;
        fixture.componentInstance.maxLen = 3;
        fixture.componentInstance.pattern = '.{3,}';
        fixture.detectChanges();

        const newForm = new FormGroup({
          'login': new FormControl(''),
          'min': new FormControl(''),
          'max': new FormControl(''),
          'pattern': new FormControl('')
        });
        fixture.componentInstance.form = newForm;
        fixture.detectChanges();

        fixture.componentInstance.required = false;
        fixture.componentInstance.minLen = null!;
        fixture.componentInstance.maxLen = null!;
        fixture.componentInstance.pattern = null!;
        fixture.detectChanges();

        expect(newForm.hasError('required', ['login'])).toEqual(false);
        expect(newForm.hasError('minlength', ['min'])).toEqual(false);
        expect(newForm.hasError('maxlength', ['max'])).toEqual(false);
        expect(newForm.hasError('pattern', ['pattern'])).toEqual(false);
        expect(newForm.valid).toEqual(true);
      });

      it('should use async validators defined in the html', fakeAsync(() => {
           const fixture = initTest(UniqLoginWrapper, UniqLoginValidator);
           const form = new FormGroup({'login': new FormControl('')});
           tick();
           fixture.componentInstance.form = form;
           fixture.detectChanges();

           expect(form.pending).toEqual(true);
           tick(100);

           expect(form.hasError('uniqLogin', ['login'])).toEqual(true);

           const input = fixture.debugElement.query(By.css('input'));
           input.nativeElement.value = 'expected';
           dispatchEvent(input.nativeElement, 'input');
           tick(100);

           expect(form.valid).toEqual(true);
         }));

      it('should use sync validators defined in the model', () => {
        const fixture = initTest(FormGroupComp);
        const form = new FormGroup({'login': new FormControl('aa', Validators.required)});
        fixture.componentInstance.form = form;
        fixture.detectChanges();
        expect(form.valid).toEqual(true);

        const input = fixture.debugElement.query(By.css('input'));
        input.nativeElement.value = '';
        dispatchEvent(input.nativeElement, 'input');

        expect(form.valid).toEqual(false);
      });

      it('should use async validators defined in the model', fakeAsync(() => {
           const fixture = initTest(FormGroupComp);
           const control =
               new FormControl('', Validators.required, uniqLoginAsyncValidator('expected'));
           const form = new FormGroup({'login': control});
           fixture.componentInstance.form = form;
           fixture.detectChanges();
           tick();

           expect(form.hasError('required', ['login'])).toEqual(true);

           const input = fixture.debugElement.query(By.css('input'));
           input.nativeElement.value = 'wrong value';
           dispatchEvent(input.nativeElement, 'input');

           expect(form.pending).toEqual(true);
           tick();

           expect(form.hasError('uniqLogin', ['login'])).toEqual(true);

           input.nativeElement.value = 'expected';
           dispatchEvent(input.nativeElement, 'input');
           tick();

           expect(form.valid).toEqual(true);
         }));

      it('async validator should not override result of sync validator', fakeAsync(() => {
           const fixture = initTest(FormGroupComp);
           const control =
               new FormControl('', Validators.required, uniqLoginAsyncValidator('expected', 100));
           fixture.componentInstance.form = new FormGroup({'login': control});
           fixture.detectChanges();
           tick();

           expect(control.hasError('required')).toEqual(true);

           const input = fixture.debugElement.query(By.css('input'));
           input.nativeElement.value = 'expected';
           dispatchEvent(input.nativeElement, 'input');

           expect(control.pending).toEqual(true);

           input.nativeElement.value = '';
           dispatchEvent(input.nativeElement, 'input');
           tick(110);

           expect(control.valid).toEqual(false);
         }));

      it('should handle async validation changes in parent and child controls', fakeAsync(() => {
           const fixture = initTest(FormGroupComp);
           const control = new FormControl(
               '', Validators.required, asyncValidator(c => !!c.value && c.value.length > 3, 100));
           const form = new FormGroup(
               {'login': control}, null,
               asyncValidator(c => c.get('login')!.value.includes('angular'), 200));
           fixture.componentInstance.form = form;
           fixture.detectChanges();
           tick();

           // Initially, the form is invalid because the nested mandatory control is empty
           expect(control.hasError('required')).toEqual(true);
           expect(form.value).toEqual({'login': ''});
           expect(form.invalid).toEqual(true);

           // Setting a value in the form control that will trigger the registered asynchronous
           // validation
           const input = fixture.debugElement.query(By.css('input'));
           input.nativeElement.value = 'angul';
           dispatchEvent(input.nativeElement, 'input');

           // The form control asynchronous validation is in progress (for 100 ms)
           expect(control.pending).toEqual(true);

           tick(100);

           // Now the asynchronous validation has resolved, and since the form control value
           // (`angul`) has a length > 3, the validation is successful
           expect(control.invalid).toEqual(false);

           // Even if the child control is valid, the form control is pending because it is still
           // waiting for its own validation
           expect(form.pending).toEqual(true);

           tick(100);

           // Login form control is valid. However, the form control is invalid because `angul` does
           // not include `angular`
           expect(control.invalid).toEqual(false);
           expect(form.pending).toEqual(false);
           expect(form.invalid).toEqual(true);

           // Setting a value that would be trigger "VALID" form state
           input.nativeElement.value = 'angular!';
           dispatchEvent(input.nativeElement, 'input');

           // Since the form control value changed, its asynchronous validation runs for 100ms
           expect(control.pending).toEqual(true);

           tick(100);

           // Even if the child control is valid, the form control is pending because it is still
           // waiting for its own validation
           expect(control.invalid).toEqual(false);
           expect(form.pending).toEqual(true);

           tick(100);

           // Now, the form is valid because its own asynchronous validation has resolved
           // successfully, because the form control value `angular` includes the `angular` string
           expect(control.invalid).toEqual(false);
           expect(form.pending).toEqual(false);
           expect(form.invalid).toEqual(false);
         }));

      it('should cancel observable properly between validation runs', fakeAsync(() => {
           const fixture = initTest(FormControlComp);
           const resultArr: number[] = [];
           fixture.componentInstance.control =
               new FormControl('', null!, observableValidator(resultArr));
           fixture.detectChanges();
           tick(100);

           expect(resultArr.length).toEqual(1, `Expected source observable to emit once on init.`);

           const input = fixture.debugElement.query(By.css('input'));
           input.nativeElement.value = 'a';
           dispatchEvent(input.nativeElement, 'input');
           fixture.detectChanges();

           input.nativeElement.value = 'aa';
           dispatchEvent(input.nativeElement, 'input');
           fixture.detectChanges();

           tick(100);
           expect(resultArr.length)
               .toEqual(2, `Expected original observable to be canceled on the next value change.`);
         }));

      describe('min and max validators', () => {
        function getComponent(dir: string): Type<MinMaxFormControlComp|MinMaxFormControlNameComp> {
          return dir === 'formControl' ? MinMaxFormControlComp : MinMaxFormControlNameComp;
        }
        // Run tests for both `FormControlName` and `FormControl` directives
        ['formControl', 'formControlName'].forEach((dir: string) => {
          it('should validate max', () => {
            const fixture = initTest(getComponent(dir));
            const control = new FormControl(5);
            fixture.componentInstance.control = control;
            fixture.componentInstance.form = new FormGroup({'pin': control});
            fixture.detectChanges();

            const input = fixture.debugElement.query(By.css('input')).nativeElement;
            const form = fixture.componentInstance.form;

            expect(input.value).toEqual('5');
            expect(form.valid).toBeTruthy();
            expect(form.controls.pin.errors).toBeNull();

            input.value = 2;
            dispatchEvent(input, 'input');
            expect(form.value).toEqual({pin: 2});
            expect(form.valid).toBeTruthy();
            expect(form.controls.pin.errors).toBeNull();

            fixture.componentInstance.max = 1;
            fixture.detectChanges();

            expect(form.valid).toBeFalse();
            expect(form.controls.pin.errors).toEqual({max: {max: 1, actual: 2}});
          });

          it('should apply max validation when control value is defined as a string', () => {
            const fixture = initTest(getComponent(dir));
            const control = new FormControl('5');
            fixture.componentInstance.control = control;
            fixture.componentInstance.form = new FormGroup({'pin': control});
            fixture.detectChanges();

            const input = fixture.debugElement.query(By.css('input')).nativeElement;
            const form = fixture.componentInstance.form;

            expect(input.value).toEqual('5');
            expect(form.valid).toBeTruthy();
            expect(form.controls.pin.errors).toBeNull();

            input.value = '2';
            dispatchEvent(input, 'input');
            expect(form.value).toEqual({pin: 2});
            expect(form.valid).toBeTruthy();
            expect(form.controls.pin.errors).toBeNull();

            fixture.componentInstance.max = 1;
            fixture.detectChanges();
            expect(form.valid).toBeFalse();
            expect(form.controls.pin.errors).toEqual({max: {max: 1, actual: 2}});
          });

          it('should validate min', () => {
            const fixture = initTest(getComponent(dir));
            const control = new FormControl(5);
            fixture.componentInstance.control = control;
            fixture.componentInstance.form = new FormGroup({'pin': control});
            fixture.detectChanges();

            const input = fixture.debugElement.query(By.css('input')).nativeElement;
            const form = fixture.componentInstance.form;

            expect(input.value).toEqual('5');
            expect(form.valid).toBeTruthy();
            expect(form.controls.pin.errors).toBeNull();

            input.value = 2;
            dispatchEvent(input, 'input');
            expect(form.value).toEqual({pin: 2});
            expect(form.valid).toBeTruthy();
            expect(form.controls.pin.errors).toBeNull();

            fixture.componentInstance.min = 5;
            fixture.detectChanges();
            expect(form.valid).toBeFalse();
            expect(form.controls.pin.errors).toEqual({min: {min: 5, actual: 2}});
          });

          it('should apply min validation when control value is defined as a string', () => {
            const fixture = initTest(getComponent(dir));
            const control = new FormControl('5');
            fixture.componentInstance.control = control;
            fixture.componentInstance.form = new FormGroup({'pin': control});
            fixture.detectChanges();

            const input = fixture.debugElement.query(By.css('input')).nativeElement;
            const form = fixture.componentInstance.form;

            expect(input.value).toEqual('5');
            expect(form.valid).toBeTruthy();
            expect(form.controls.pin.errors).toBeNull();

            input.value = '2';
            dispatchEvent(input, 'input');
            expect(form.value).toEqual({pin: 2});
            expect(form.valid).toBeTruthy();
            expect(form.controls.pin.errors).toBeNull();

            fixture.componentInstance.min = 5;
            fixture.detectChanges();
            expect(form.valid).toBeFalse();
            expect(form.controls.pin.errors).toEqual({min: {min: 5, actual: 2}});
          });

          it('should run min/max validation for empty values', () => {
            const fixture = initTest(getComponent(dir));
            const minValidateFnSpy = spyOn(MinValidator.prototype, 'validate');
            const maxValidateFnSpy = spyOn(MaxValidator.prototype, 'validate');

            const control = new FormControl();
            fixture.componentInstance.control = control;
            fixture.componentInstance.form = new FormGroup({'pin': control});
            fixture.detectChanges();

            const input = fixture.debugElement.query(By.css('input')).nativeElement;
            const form = fixture.componentInstance.form;

            expect(input.value).toEqual('');
            expect(form.valid).toBeTruthy();
            expect(form.controls.pin.errors).toBeNull();
            expect(minValidateFnSpy).toHaveBeenCalled();
            expect(maxValidateFnSpy).toHaveBeenCalled();
          });

          it('should run min/max validation when constraints are represented as strings', () => {
            const fixture = initTest(getComponent(dir));
            const control = new FormControl(5);

            // Run tests when min and max are defined as strings.
            fixture.componentInstance.min = '1';
            fixture.componentInstance.max = '10';

            fixture.componentInstance.control = control;
            fixture.componentInstance.form = new FormGroup({'pin': control});
            fixture.detectChanges();

            const input = fixture.debugElement.query(By.css('input')).nativeElement;
            const form = fixture.componentInstance.form;

            expect(input.value).toEqual('5');
            expect(form.valid).toBeTruthy();
            expect(form.controls.pin.errors).toBeNull();

            input.value = 2;  // inside [1, 10] range
            dispatchEvent(input, 'input');
            expect(form.value).toEqual({pin: 2});
            expect(form.valid).toBeTruthy();
            expect(form.controls.pin.errors).toBeNull();

            input.value = -2;  // outside [1, 10] range
            dispatchEvent(input, 'input');
            expect(form.value).toEqual({pin: -2});
            expect(form.valid).toBeFalse();
            expect(form.controls.pin.errors).toEqual({min: {min: 1, actual: -2}});

            input.value = 20;  // outside [1, 10] range
            dispatchEvent(input, 'input');
            expect(form.valid).toBeFalse();
            expect(form.controls.pin.errors).toEqual({max: {max: 10, actual: 20}});
          });

          it('should run min/max validation for negative values', () => {
            const fixture = initTest(getComponent(dir));
            const control = new FormControl(-30);
            fixture.componentInstance.control = control;
            fixture.componentInstance.form = new FormGroup({'pin': control});
            fixture.componentInstance.min = -20;
            fixture.componentInstance.max = -10;
            fixture.detectChanges();

            const input = fixture.debugElement.query(By.css('input')).nativeElement;
            const form = fixture.componentInstance.form;

            expect(input.value).toEqual('-30');
            expect(form.valid).toBeFalse();
            expect(form.controls.pin.errors).toEqual({min: {min: -20, actual: -30}});

            input.value = -15;
            dispatchEvent(input, 'input');
            expect(form.value).toEqual({pin: -15});
            expect(form.valid).toBeTruthy();
            expect(form.controls.pin.errors).toBeNull();

            input.value = -5;
            dispatchEvent(input, 'input');
            expect(form.value).toEqual({pin: -5});
            expect(form.valid).toBeFalse();
            expect(form.controls.pin.errors).toEqual({max: {max: -10, actual: -5}});

            input.value = 0;
            dispatchEvent(input, 'input');
            expect(form.value).toEqual({pin: 0});
            expect(form.valid).toBeFalse();
            expect(form.controls.pin.errors).toEqual({max: {max: -10, actual: 0}});
          });
        });
      });
    });

    describe('errors', () => {
      it('should throw if a form isn\'t passed into formGroup', () => {
        const fixture = initTest(FormGroupComp);

        expect(() => fixture.detectChanges())
            .toThrowError(new RegExp(`formGroup expects a FormGroup instance`));
      });

      it('should throw if formControlName is used without a control container', () => {
        TestBed.overrideComponent(FormGroupComp, {
          set: {
            template: `
          <input type="text" formControlName="login">
        `
          }
        });
        const fixture = initTest(FormGroupComp);

        expect(() => fixture.detectChanges())
            .toThrowError(
                new RegExp(`formControlName must be used with a parent formGroup directive`));
      });

      it('should throw if formControlName is used with NgForm', () => {
        TestBed.overrideComponent(FormGroupComp, {
          set: {
            template: `
          <form>
            <input type="text" formControlName="login">
          </form>
        `
          }
        });
        const fixture = initTest(FormGroupComp);

        expect(() => fixture.detectChanges())
            .toThrowError(
                new RegExp(`formControlName must be used with a parent formGroup directive.`));
      });

      it('should throw if formControlName is used with NgModelGroup', () => {
        TestBed.overrideComponent(FormGroupComp, {
          set: {
            template: `
          <form>
            <div ngModelGroup="parent">
              <input type="text" formControlName="login">
            </div>
          </form>
        `
          }
        });
        const fixture = initTest(FormGroupComp);

        expect(() => fixture.detectChanges())
            .toThrowError(
                new RegExp(`formControlName cannot be used with an ngModelGroup parent.`));
      });

      it('should throw if formGroupName is used without a control container', () => {
        TestBed.overrideComponent(FormGroupComp, {
          set: {
            template: `
          <div formGroupName="person">
            <input type="text" formControlName="login">
          </div>
        `
          }
        });
        const fixture = initTest(FormGroupComp);

        expect(() => fixture.detectChanges())
            .toThrowError(
                new RegExp(`formGroupName must be used with a parent formGroup directive`));
      });

      it('should throw if formGroupName is used with NgForm', () => {
        TestBed.overrideComponent(FormGroupComp, {
          set: {
            template: `
          <form>
            <div formGroupName="person">
              <input type="text" formControlName="login">
            </div>
          </form>
        `
          }
        });
        const fixture = initTest(FormGroupComp);

        expect(() => fixture.detectChanges())
            .toThrowError(
                new RegExp(`formGroupName must be used with a parent formGroup directive.`));
      });

      it('should throw if formArrayName is used without a control container', () => {
        TestBed.overrideComponent(FormGroupComp, {
          set: {
            template: `
         <div formArrayName="cities">
           <input type="text" formControlName="login">
         </div>`
          }
        });
        const fixture = initTest(FormGroupComp);

        expect(() => fixture.detectChanges())
            .toThrowError(
                new RegExp(`formArrayName must be used with a parent formGroup directive`));
      });

      it('should throw if ngModel is used alone under formGroup', () => {
        TestBed.overrideComponent(FormGroupComp, {
          set: {
            template: `
         <div [formGroup]="form">
           <input type="text" [(ngModel)]="data">
         </div>
        `
          }
        });
        const fixture = initTest(FormGroupComp);
        fixture.componentInstance.form = new FormGroup({});

        expect(() => fixture.detectChanges())
            .toThrowError(new RegExp(
                `ngModel cannot be used to register form controls with a parent formGroup directive.`));
      });

      it('should not throw if ngModel is used alone under formGroup with standalone: true', () => {
        TestBed.overrideComponent(FormGroupComp, {
          set: {
            template: `
         <div [formGroup]="form">
            <input type="text" [(ngModel)]="data" [ngModelOptions]="{standalone: true}">
         </div>
        `
          }
        });
        const fixture = initTest(FormGroupComp);
        fixture.componentInstance.form = new FormGroup({});

        expect(() => fixture.detectChanges()).not.toThrowError();
      });

      it('should throw if ngModel is used alone with formGroupName', () => {
        TestBed.overrideComponent(FormGroupComp, {
          set: {
            template: `
          <div [formGroup]="form">
            <div formGroupName="person">
              <input type="text" [(ngModel)]="data">
            </div>
          </div>
        `
          }
        });
        const fixture = initTest(FormGroupComp);
        fixture.componentInstance.form = new FormGroup({person: new FormGroup({})});

        expect(() => fixture.detectChanges())
            .toThrowError(new RegExp(
                `ngModel cannot be used to register form controls with a parent formGroupName or formArrayName directive.`));
      });

      it('should throw if ngModelGroup is used with formGroup', () => {
        TestBed.overrideComponent(FormGroupComp, {
          set: {
            template: `
          <div [formGroup]="form">
            <div ngModelGroup="person">
              <input type="text" [(ngModel)]="data">
            </div>
          </div>
        `
          }
        });
        const fixture = initTest(FormGroupComp);
        fixture.componentInstance.form = new FormGroup({});

        expect(() => fixture.detectChanges())
            .toThrowError(
                new RegExp(`ngModelGroup cannot be used with a parent formGroup directive`));
      });

      it('should throw if radio button name does not match formControlName attr', () => {
        TestBed.overrideComponent(FormGroupComp, {
          set: {
            template: `
          <form [formGroup]="form">hav
            <input type="radio" formControlName="food" name="drink" value="chicken">
          </form>`
          }
        });
        const fixture = initTest(FormGroupComp);
        fixture.componentInstance.form = new FormGroup({'food': new FormControl('fish')});

        expect(() => fixture.detectChanges())
            .toThrowError(new RegExp('If you define both a name and a formControlName'));
      });
    });

    describe('IME events', () => {
      it('should determine IME event handling depending on platform by default', () => {
        const fixture = initTest(FormControlComp);
        fixture.componentInstance.control = new FormControl('oldValue');
        fixture.detectChanges();

        const inputEl = fixture.debugElement.query(By.css('input'));
        const inputNativeEl = inputEl.nativeElement;
        expect(inputNativeEl.value).toEqual('oldValue');

        inputEl.triggerEventHandler('compositionstart', null);

        inputNativeEl.value = 'updatedValue';
        dispatchEvent(inputNativeEl, 'input');
        const isAndroid = /android (\d+)/.test(getDOM().getUserAgent().toLowerCase());

        if (isAndroid) {
          // On Android, values should update immediately
          expect(fixture.componentInstance.control.value).toEqual('updatedValue');
        } else {
          // On other platforms, values should wait for compositionend
          expect(fixture.componentInstance.control.value).toEqual('oldValue');

          inputEl.triggerEventHandler('compositionend', {target: {value: 'updatedValue'}});
          fixture.detectChanges();
          expect(fixture.componentInstance.control.value).toEqual('updatedValue');
        }
      });

      it('should hold IME events until compositionend if composition mode', () => {
        TestBed.overrideComponent(
            FormControlComp,
            {set: {providers: [{provide: COMPOSITION_BUFFER_MODE, useValue: true}]}});
        const fixture = initTest(FormControlComp);
        fixture.componentInstance.control = new FormControl('oldValue');
        fixture.detectChanges();

        const inputEl = fixture.debugElement.query(By.css('input'));
        const inputNativeEl = inputEl.nativeElement;
        expect(inputNativeEl.value).toEqual('oldValue');

        inputEl.triggerEventHandler('compositionstart', null);

        inputNativeEl.value = 'updatedValue';
        dispatchEvent(inputNativeEl, 'input');

        // should not update when compositionstart
        expect(fixture.componentInstance.control.value).toEqual('oldValue');

        inputEl.triggerEventHandler('compositionend', {target: {value: 'updatedValue'}});

        fixture.detectChanges();

        // should update when compositionend
        expect(fixture.componentInstance.control.value).toEqual('updatedValue');
      });

      it('should work normally with composition events if composition mode is off', () => {
        TestBed.overrideComponent(
            FormControlComp,
            {set: {providers: [{provide: COMPOSITION_BUFFER_MODE, useValue: false}]}});
        const fixture = initTest(FormControlComp);
        fixture.componentInstance.control = new FormControl('oldValue');
        fixture.detectChanges();

        const inputEl = fixture.debugElement.query(By.css('input'));
        const inputNativeEl = inputEl.nativeElement;
        expect(inputNativeEl.value).toEqual('oldValue');

        inputEl.triggerEventHandler('compositionstart', null);

        inputNativeEl.value = 'updatedValue';
        dispatchEvent(inputNativeEl, 'input');
        fixture.detectChanges();

        // formControl should update normally
        expect(fixture.componentInstance.control.value).toEqual('updatedValue');
      });
    });

    describe('cleanup', () => {
      // Symbol that indicates to the verification logic that a certain spy was not expected to be
      // invoked. This symbol is used by the test helpers below.
      const SHOULD_NOT_BE_CALLED = Symbol('SHOULD_NOT_BE_INVOKED');

      function expectValidatorsToBeCalled(
          syncValidatorSpy: jasmine.Spy, asyncValidatorSpy: jasmine.Spy,
          expected: {ctx: any, count: number}) {
        [syncValidatorSpy, asyncValidatorSpy].forEach((spy: jasmine.Spy<jasmine.Func>) => {
          spy.calls.all().forEach((call: jasmine.CallInfo<jasmine.Func>) => {
            expect(call.args[0]).toBe(expected.ctx);
          });
          expect(spy).toHaveBeenCalledTimes(expected.count);
        });
      }

      function createValidatorSpy(): jasmine.Spy<jasmine.Func> {
        return jasmine.createSpy('asyncValidator').and.returnValue(null);
      }
      function createAsyncValidatorSpy(): jasmine.Spy<jasmine.Func> {
        return jasmine.createSpy('asyncValidator').and.returnValue(Promise.resolve(null));
      }

      // Sets up a control with validators and value accessors configured for a test.
      function addOwnValidatorsAndAttachSpies(control: AbstractControl, fromView: any = {}): void {
        const validatorSpy = createValidatorSpy();
        const asyncValidatorSpy = createAsyncValidatorSpy();
        const valueChangesSpy = jasmine.createSpy('controlValueChangesListener');
        const debug: any = {
          validatorSpy,
          asyncValidatorSpy,
          valueChangesSpy,
        };
        if (fromView.viewValidators) {
          const [syncValidatorClass, asyncValidatorClass] = fromView.viewValidators;
          debug.viewValidatorSpy = validatorSpyOn(syncValidatorClass);
          debug.viewAsyncValidatorSpy = validatorSpyOn(asyncValidatorClass);
        }
        if (fromView.valueAccessor) {
          debug.valueAccessorSpy = spyOn(fromView.valueAccessor.prototype, 'writeValue');
        }
        (control as any).__debug__ = debug;

        control.valueChanges.subscribe(valueChangesSpy);
        control.setValidators(validatorSpy);
        control.setAsyncValidators(asyncValidatorSpy);
      }

      // Resets all spies associated with given controls.
      function resetSpies(...controls: AbstractControl[]): void {
        controls.forEach((control: any) => {
          const debug = control.__debug__;
          debug.validatorSpy.calls.reset();
          debug.asyncValidatorSpy.calls.reset();
          debug.valueChangesSpy.calls.reset();
          if (debug.viewValidatorSpy) {
            debug.viewValidatorSpy.calls.reset();
          }
          if (debug.viewAsyncValidatorSpy) {
            debug.viewAsyncValidatorSpy.calls.reset();
          }
          if (debug.valueAccessorSpy) {
            debug.valueAccessorSpy.calls.reset();
          }
        });
      }

      // Verifies whether spy calls match expectations.
      function verifySpyCalls(spy: any, expectedContext: any, expectedCallCount?: number) {
        if (expectedContext === SHOULD_NOT_BE_CALLED) {
          expect(spy).not.toHaveBeenCalled();
        } else {
          expect(spy).toHaveBeenCalledWith(expectedContext);
          if (expectedCallCount !== undefined) {
            expect(spy.calls.count()).toBe(expectedCallCount);
          }
        }
      }

      // Verify whether all spies attached to a given control match expectations.
      function verifySpies(control: AbstractControl, expected: any = {}) {
        const debug = (control as any).__debug__;
        const viewValidatorCallCount = expected.viewValidatorCallCount ?? 1;
        const ownValidatorCallCount = expected.ownValidatorCallCount ?? 1;
        const valueAccessorCallCount = expected.valueAccessorCallCount ?? 1;
        verifySpyCalls(debug.validatorSpy, expected.ownValidators, ownValidatorCallCount);
        verifySpyCalls(debug.asyncValidatorSpy, expected.ownValidators, ownValidatorCallCount);
        verifySpyCalls(debug.valueChangesSpy, expected.valueChanges);
        if (debug.viewValidatorSpy) {
          verifySpyCalls(debug.viewValidatorSpy, expected.viewValidators, viewValidatorCallCount);
        }
        if (debug.viewAsyncValidatorSpy) {
          verifySpyCalls(
              debug.viewAsyncValidatorSpy, expected.viewValidators, viewValidatorCallCount);
        }
        if (debug.valueAccessorSpy) {
          verifySpyCalls(debug.valueAccessorSpy, expected.valueAccessor, valueAccessorCallCount);
        }
      }

      // Init a test with a predefined set of validator and value accessor classes.
      function initCleanupTest(component: Type<any>) {
        const fixture = initTest(
            component, ViewValidatorA, AsyncViewValidatorA, ViewValidatorB, AsyncViewValidatorB,
            ViewValidatorC, AsyncViewValidatorC, ValueAccessorA, ValueAccessorB);
        fixture.detectChanges();
        return fixture;
      }

      it('should clean up validators when FormGroup is replaced', () => {
        const fixture = initTest(FormGroupWithValidators, ViewValidatorA, AsyncViewValidatorA);
        fixture.detectChanges();

        const newForm = new FormGroup({login: new FormControl('NEW')});
        const oldForm = fixture.componentInstance.form;

        // Update `form` input with a new value.
        fixture.componentInstance.form = newForm;
        fixture.detectChanges();

        const validatorSpy = validatorSpyOn(ViewValidatorA);
        const asyncValidatorSpy = validatorSpyOn(AsyncViewValidatorA);

        // Calling `setValue` for the OLD form should NOT trigger validator calls.
        oldForm.setValue({login: 'SOME-OLD-VALUE'});
        expect(validatorSpy).not.toHaveBeenCalled();
        expect(asyncValidatorSpy).not.toHaveBeenCalled();

        // Calling `setValue` for the NEW (active) form should trigger validator calls.
        newForm.setValue({login: 'SOME-NEW-VALUE'});
        expectValidatorsToBeCalled(validatorSpy, asyncValidatorSpy, {ctx: newForm, count: 1});
      });

      it('should clean up validators when FormControl inside FormGroup is replaced', () => {
        const fixture = initTest(FormControlWithValidators, ViewValidatorA, AsyncViewValidatorA);
        fixture.detectChanges();

        const newControl = new FormControl('NEW')!;
        const oldControl = fixture.componentInstance.form.get('login')!;

        const validatorSpy = validatorSpyOn(ViewValidatorA);
        const asyncValidatorSpy = validatorSpyOn(AsyncViewValidatorA);

        // Update `login` form control with a new `FormControl` instance.
        fixture.componentInstance.form.removeControl('login');
        fixture.componentInstance.form.addControl('login', newControl);
        fixture.detectChanges();

        validatorSpy.calls.reset();
        asyncValidatorSpy.calls.reset();

        // Calling `setValue` for the OLD control should NOT trigger validator calls.
        oldControl.setValue('SOME-OLD-VALUE');
        expect(validatorSpy).not.toHaveBeenCalled();
        expect(asyncValidatorSpy).not.toHaveBeenCalled();

        // Calling `setValue` for the NEW (active) control should trigger validator calls.
        newControl.setValue('SOME-NEW-VALUE');
        expectValidatorsToBeCalled(validatorSpy, asyncValidatorSpy, {ctx: newControl, count: 1});
      });

      it('should keep control in pending state if async validator never emits', fakeAsync(() => {
           const fixture = initTest(FormControlWithAsyncValidatorFn);
           fixture.detectChanges();

           const control = fixture.componentInstance.form.get('login')!;
           expect(control.status).toBe('PENDING');

           control.setValue('SOME-NEW-VALUE');
           tick();

           // Since validator never emits, we expect a control to be retained in a pending state.
           expect(control.status).toBe('PENDING');
           expect(control.errors).toBe(null);
         }));

      it('should call validators defined via `set[Async]Validators` after view init', () => {
        const fixture = initTest(FormControlWithValidators, ViewValidatorA, AsyncViewValidatorA);
        fixture.detectChanges();

        const control = fixture.componentInstance.form.get('login')!;

        const initialValidatorSpy = validatorSpyOn(ViewValidatorA);
        const initialAsyncValidatorSpy = validatorSpyOn(AsyncViewValidatorA);

        initialValidatorSpy.calls.reset();
        initialAsyncValidatorSpy.calls.reset();

        control.setValue('VALUE-A');

        // Expect initial validators (setup during view creation) to be called.
        expectValidatorsToBeCalled(
            initialValidatorSpy, initialAsyncValidatorSpy, {ctx: control, count: 1});

        initialValidatorSpy.calls.reset();
        initialAsyncValidatorSpy.calls.reset();

        // Create new validators and corresponding spies.
        const newValidatorSpy = jasmine.createSpy('newValidator').and.returnValue(null);
        const newAsyncValidatorSpy =
            jasmine.createSpy('newAsyncValidator').and.returnValue(of(null));

        // Set new validators to a control that is already used in a view.
        // Expect that new validators are applied and old validators are removed.
        control.setValidators(newValidatorSpy);
        control.setAsyncValidators(newAsyncValidatorSpy);

        // Update control value to trigger validation.
        control.setValue('VALUE-B');

        // Verify that initial (inactive) validators were not called.
        expect(initialValidatorSpy).not.toHaveBeenCalled();
        expect(initialAsyncValidatorSpy).not.toHaveBeenCalled();

        // Verify that newly applied validators were executed.
        expectValidatorsToBeCalled(newValidatorSpy, newAsyncValidatorSpy, {ctx: control, count: 1});
      });

      it('should cleanup validators on a control used for multiple `formControlName` directives',
         () => {
           const fixture =
               initTest(NgForFormControlWithValidators, ViewValidatorA, AsyncViewValidatorA);
           fixture.detectChanges();

           const newControl = new FormControl('b')!;
           const oldControl = fixture.componentInstance.form.get('login')!;

           const validatorSpy = validatorSpyOn(ViewValidatorA);
           const asyncValidatorSpy = validatorSpyOn(AsyncViewValidatorA);

           // Case 1: replace `login` form control with a new `FormControl` instance.
           fixture.componentInstance.form.removeControl('login');
           fixture.componentInstance.form.addControl('login', newControl);
           fixture.detectChanges();

           // Check that validators were called with a new control as a context
           // and each validator function was called for each control (so 3 times each).
           expectValidatorsToBeCalled(validatorSpy, asyncValidatorSpy, {ctx: newControl, count: 3});

           validatorSpy.calls.reset();
           asyncValidatorSpy.calls.reset();

           // Calling `setValue` for the OLD control should NOT trigger validator calls.
           oldControl.setValue('SOME-OLD-VALUE');
           expect(validatorSpy).not.toHaveBeenCalled();
           expect(asyncValidatorSpy).not.toHaveBeenCalled();

           // Calling `setValue` for the NEW (active) control should trigger validator calls.
           newControl.setValue('SOME-NEW-VALUE');

           // Check that setting a value on a new control triggers validator calls.
           expectValidatorsToBeCalled(validatorSpy, asyncValidatorSpy, {ctx: newControl, count: 3});

           // Case 2: update `logins` to render a new list of elements.
           fixture.componentInstance.logins = ['a', 'b', 'c', 'd', 'e', 'f'];
           fixture.detectChanges();

           validatorSpy.calls.reset();
           asyncValidatorSpy.calls.reset();

           // Calling `setValue` for the NEW (active) control should trigger validator calls.
           newControl.setValue('SOME-NEW-VALUE-2');

           // Check that setting a value on a new control triggers validator calls for updated set
           // of controls (one for each element in the `logins` array).
           expectValidatorsToBeCalled(validatorSpy, asyncValidatorSpy, {ctx: newControl, count: 6});
         });

      it('should cleanup directive-specific callbacks only', () => {
        const fixture = initTest(MultipleFormControls, ViewValidatorA, AsyncViewValidatorA);
        fixture.detectChanges();

        const sharedControl = fixture.componentInstance.control;

        const validatorSpy = validatorSpyOn(ViewValidatorA);
        const asyncValidatorSpy = validatorSpyOn(AsyncViewValidatorA);

        sharedControl.setValue('b');
        fixture.detectChanges();

        // Check that validators were called for each `formControlName` directive instance
        // (2 times total).
        expectValidatorsToBeCalled(validatorSpy, asyncValidatorSpy, {ctx: sharedControl, count: 2});

        // Replace formA with a new instance. This will trigger destroy operation for the
        // `formControlName` directive that is bound to the `control` FormControl instance.
        const newFormA = new FormGroup({login: new FormControl('new-a')});
        fixture.componentInstance.formA = newFormA;
        fixture.detectChanges();

        validatorSpy.calls.reset();
        asyncValidatorSpy.calls.reset();

        // Update control with a new value.
        sharedControl.setValue('d');
        fixture.detectChanges();

        // We should still see an update to the second <input>.
        expect(fixture.nativeElement.querySelector('#login').value).toBe('d');
        expectValidatorsToBeCalled(validatorSpy, asyncValidatorSpy, {ctx: sharedControl, count: 1});
      });

      it('should clean up callbacks when FormControlDirective is destroyed (simple)', () => {
        // Scenario:
        // ---------
        // [formControl] *ngIf

        const control = new FormControl();
        addOwnValidatorsAndAttachSpies(control, {
          viewValidators: [ViewValidatorA, AsyncViewValidatorA],
          valueAccessor: ValueAccessorA,
        });

        @Component({
          selector: 'app',
          template: `
            <input *ngIf="visible" type="text" [formControl]="control" cva-a validators-a>
          `
        })
        class App {
          visible = true;
          control = control;
        }

        const fixture = initCleanupTest(App);

        resetSpies(control);

        // Case 1: update control value and verify all spies were called.
        control.setValue('Initial value');
        fixture.detectChanges();

        verifySpies(control, {
          ownValidators: control,
          viewValidators: control,
          valueAccessor: 'Initial value',
          valueChanges: 'Initial value',
        });

        // Case 2: hide form control and verify no directive-related callbacks
        // (validators, value accessors) were invoked.
        fixture.componentInstance.visible = false;
        fixture.detectChanges();

        // Reset all spies again, prepare for next check.
        resetSpies(control);

        control.setValue('Updated Value');

        // Expectation:
        // - FormControlDirective was destroyed and connection to default value accessor and view
        //   validators should also be destroyed.
        verifySpies(control, {
          viewValidators: SHOULD_NOT_BE_CALLED,
          ownValidators: control,
          valueAccessor: SHOULD_NOT_BE_CALLED,
          valueChanges: 'Updated Value',
        });

        // Case 3: make the form control visible again and verify all callbacks are correctly
        // attached.
        fixture.componentInstance.visible = true;
        fixture.detectChanges();

        // Reset all spies again, prepare for next check.
        resetSpies(control);

        control.setValue('Updated Value (v2)');

        verifySpies(control, {
          viewValidators: control,
          ownValidators: control,
          valueAccessor: 'Updated Value (v2)',
          valueChanges: 'Updated Value (v2)',
        });
      });

      it('should clean up when FormControlDirective is destroyed (multiple instances)', () => {
        // Scenario:
        // ---------
        // [formControl] *ngIf
        // [formControl]

        const control = new FormControl();
        addOwnValidatorsAndAttachSpies(control, {
          viewValidators: [ViewValidatorA, AsyncViewValidatorA],
          valueAccessor: ValueAccessorA,
        });

        @Component({
          selector: 'app',
          template: `
            <input type="text" [formControl]="control" cva-a validators-a *ngIf="visible">
            <input type="text" [formControl]="control" cva-b>
          `
        })
        class App {
          visible = true;
          control = control;
        }

        const fixture = initCleanupTest(App);

        // Value accessor for the second <input> without *ngIf.
        const valueAccessorBSpy = spyOn(ValueAccessorB.prototype, 'writeValue');

        // Reset all spies.
        valueAccessorBSpy.calls.reset();
        resetSpies(control);

        // Case 1: update control value and verify all spies were called.
        control.setValue('Initial value');
        fixture.detectChanges();

        expect(valueAccessorBSpy).toHaveBeenCalledWith('Initial value');
        verifySpies(control, {
          ownValidators: control,
          viewValidators: control,
          valueAccessor: 'Initial value',
          valueChanges: 'Initial value',
        });

        // Case 2: hide form control and verify no directive-related callbacks
        // (validators, value accessors) were invoked.
        fixture.componentInstance.visible = false;
        fixture.detectChanges();

        // Reset all spies again, prepare for next check.
        valueAccessorBSpy.calls.reset();
        resetSpies(control);

        control.setValue('Updated Value');

        // Expectation:
        // - FormControlDirective was destroyed and connection to a value accessor and view
        //   validators should also be destroyed.
        // - Since there is a second instance of the FormControlDirective directive present in the
        //   template, we expect to see see calls to value accessor B (since it's applied to
        //   that directive instance) and validators applied on a control instance itself (not a
        //   part of a view setup).
        expect(valueAccessorBSpy).toHaveBeenCalledWith('Updated Value');
        verifySpies(control, {
          viewValidators: SHOULD_NOT_BE_CALLED,
          ownValidators: control,
          valueAccessor: SHOULD_NOT_BE_CALLED,
          valueChanges: 'Updated Value',
        });
      });

      it('should clean up callbacks when FormControlName directive is destroyed', () => {
        // Scenario:
        // ---------
        // [formGroup]
        //   formControlName *ngIf
        //   formControlName

        const control = new FormControl();
        addOwnValidatorsAndAttachSpies(control, {
          viewValidators: [ViewValidatorA, AsyncViewValidatorA],
          valueAccessor: ValueAccessorA,
        });

        @Component({
          selector: 'app',
          template: `
            <div [formGroup]="group">
              <input type="text" formControlName="control" cva-a validators-a *ngIf="visible">
              <input type="text" formControlName="control" cva-b>
            </div>
          `
        })
        class App {
          visible = true;
          group = new FormGroup({control});
        }

        const fixture = initCleanupTest(App);

        // DefaultValueAccessor will be used for the second <input> where no custom CVA is defined.
        const valueAccessorBSpy = spyOn(ValueAccessorB.prototype, 'writeValue');

        // Reset all spies.
        valueAccessorBSpy.calls.reset();
        resetSpies(control);

        // Case 1: update control value and verify all spies were called.
        control.setValue('Initial value');
        fixture.detectChanges();

        expect(valueAccessorBSpy).toHaveBeenCalledWith('Initial value');
        verifySpies(control, {
          viewValidators: control,
          ownValidators: control,
          valueAccessor: 'Initial value',
          valueChanges: 'Initial value',
        });

        // Case 2: hide form control and verify no directive-related callbacks
        // (validators, value accessors) were invoked.
        fixture.componentInstance.visible = false;
        fixture.detectChanges();

        // Reset all spies again, prepare for next check.
        valueAccessorBSpy.calls.reset();
        resetSpies(control);

        control.setValue('Updated value');

        // Expectation:
        // - `FormControlName` was destroyed and connection to the value accessor A and
        //   validators should also be destroyed.
        // - Since there is a second instance of `FormControlName` directive present in the
        //   template, we expect to see see calls to the value accessor B (since it's applied to
        //   that directive instance) and validators applied on a control instance itself (not a
        //   part of a view setup).
        expect(valueAccessorBSpy).toHaveBeenCalledWith('Updated value');
        verifySpies(control, {
          viewValidators: SHOULD_NOT_BE_CALLED,
          ownValidators: control,
          valueAccessor: SHOULD_NOT_BE_CALLED,
          valueChanges: 'Updated value',
        });
      });

      it('should clean up callbacks when FormGroupDirective is destroyed', () => {
        // Scenario:
        // ---------
        // [formGroup] *ngIf
        //   [formControl]

        const control = new FormControl();
        addOwnValidatorsAndAttachSpies(control, {
          viewValidators: [ViewValidatorA, AsyncViewValidatorA],
          valueAccessor: ValueAccessorA,
        });

        const group = new FormGroup({control});
        addOwnValidatorsAndAttachSpies(group, {
          viewValidators: [ViewValidatorB, AsyncViewValidatorB],
        });

        @Component({
          selector: 'app',
          template: `
            <ng-container *ngIf="visible">
              <div [formGroup]="group" validators-b>
                <input type="text" [formControl]="control" cva-a validators-a>
              </div>
            </ng-container>
          `
        })
        class App {
          visible = true;
          control = control;
          group = group;
        }

        const fixture = initCleanupTest(App);

        resetSpies(group, control);

        // Case 1: update control value and verify that all spies were called.
        control.setValue('Initial value');
        fixture.detectChanges();

        verifySpies(control, {
          viewValidators: control,
          ownValidators: control,
          valueAccessor: 'Initial value',
          valueChanges: 'Initial value',
        });
        verifySpies(group, {
          viewValidators: group,
          ownValidators: group,
          valueChanges: {control: 'Initial value'},
        });


        // Case 2: hide form group and verify that no directive-related callbacks
        // (validators, value accessors) are invoked when we set control value later.
        fixture.componentInstance.visible = false;
        fixture.detectChanges();

        // Reset all spies again, prepare for next check.
        resetSpies(group, control);

        control.setValue('Updated value');

        // Expectation:
        // - `FormGroupDirective` and `FormControlDirective` were destroyed, so connection to value
        //   accessor and view validators should also be destroyed.
        // - Own validators directly attached to FormGroup and FormControl should still be invoked.
        verifySpies(control, {
          viewValidators: SHOULD_NOT_BE_CALLED,
          ownValidators: control,
          valueAccessor: SHOULD_NOT_BE_CALLED,
          valueChanges: 'Updated value',
        });
        verifySpies(group, {
          viewValidators: SHOULD_NOT_BE_CALLED,
          ownValidators: group,
          valueChanges: {control: 'Updated value'},
        });

        // Case 3: make the form control visible again and verify all callbacks are correctly
        // attached and invoked.
        fixture.componentInstance.visible = true;
        fixture.detectChanges();

        // Reset all spies again, prepare for next check.
        resetSpies(group, control);

        control.setValue('Updated value (v2)');

        verifySpies(control, {
          viewValidators: control,
          ownValidators: control,
          valueAccessor: 'Updated value (v2)',
          valueChanges: 'Updated value (v2)',
        });
        verifySpies(group, {
          viewValidators: group,
          ownValidators: group,
          valueChanges: {control: 'Updated value (v2)'},
        });
      });

      it('should clean up when FormControl is destroyed (but parent FormGroup exists)', () => {
        // Scenario:
        // ---------
        // [formGroup]
        //   [formControl] *ngIf

        const control = new FormControl();
        addOwnValidatorsAndAttachSpies(control, {
          viewValidators: [ViewValidatorA, AsyncViewValidatorA],
          valueAccessor: ValueAccessorA,
        });

        const group = new FormGroup({control});
        addOwnValidatorsAndAttachSpies(group, {
          viewValidators: [ViewValidatorB, AsyncViewValidatorB],
        });

        @Component({
          selector: 'app',
          template: `
            <div [formGroup]="group" validators-b>
              <input *ngIf="visible" type="text" [formControl]="control" cva-a validators-a>
            </div>
          `
        })
        class App {
          visible = true;
          control = control;
          group = group;
        }

        const fixture = initCleanupTest(App);

        resetSpies(group, control);

        // Case 1: update control value and verify that all spies were called.
        control.setValue('Initial value');
        fixture.detectChanges();

        verifySpies(control, {
          viewValidators: control,
          ownValidators: control,
          valueAccessor: 'Initial value',
          valueChanges: 'Initial value',
        });
        verifySpies(group, {
          viewValidators: group,
          ownValidators: group,
          valueChanges: {control: 'Initial value'},
        });


        // Case 2: hide form group and verify that no directive-related callbacks
        // (validators, value accessors) are invoked when we set control value later.
        fixture.componentInstance.visible = false;
        fixture.detectChanges();

        // Reset all spies again, prepare for next check.
        resetSpies(group, control);

        group.setValue({control: 'Updated value'});

        // Expectation:
        // - `FormControlDirective` was destroyed, so connection to value accessor and view
        //   validators should also be destroyed.
        // - Own validators directly attached to FormGroup and FormControl should still be invoked.
        // - `FormGroupDirective` was *not* destroyed, so all view validators should be invoked.
        verifySpies(control, {
          viewValidators: SHOULD_NOT_BE_CALLED,
          ownValidators: control,
          valueAccessor: SHOULD_NOT_BE_CALLED,
          valueChanges: 'Updated value',
        });
        verifySpies(group, {
          viewValidators: group,
          ownValidators: group,
          valueChanges: {control: 'Updated value'},
        });
      });

      it('should clean up controls produced by *ngFor', () => {
        // Scenario:
        // ---------
        // [formGroup]
        //   [formControl] *ngFor

        const control = new FormControl();
        addOwnValidatorsAndAttachSpies(control, {
          viewValidators: [ViewValidatorA, AsyncViewValidatorA],
          valueAccessor: ValueAccessorA,
        });

        const group = new FormGroup({control});
        addOwnValidatorsAndAttachSpies(group, {
          viewValidators: [ViewValidatorB, AsyncViewValidatorB],
        });

        @Component({
          selector: 'app',
          template: `
            <div [formGroup]="group" validators-b *ngIf="visible">
              <ng-container *ngFor="let login of logins">
                <input type="radio" [value]="login" [formControl]="control" cva-a validators-a>
              </ng-container>
            </div>
          `
        })
        class App {
          visible = true;
          control = control;
          group = group;
          logins = ['a', 'b', 'c'];
        }

        const fixture = initCleanupTest(App);

        resetSpies(group, control);

        // Case 1: update control value and verify that all spies were called.
        control.setValue('Initial value');
        fixture.detectChanges();

        verifySpies(control, {
          viewValidatorCallCount: 3,  // since *ngFor produces 3 [formControl]s
          valueAccessorCallCount: 3,  // since *ngFor produces 3 [formControl]s
          ownValidatorCallCount: 1,
          viewValidators: control,
          ownValidators: control,
          valueAccessor: 'Initial value',
          valueChanges: 'Initial value',
        });
        verifySpies(group, {
          viewValidators: group,
          ownValidators: group,
          valueChanges: {control: 'Initial value'},
        });

        // Case 2: update the list of logins which would result in cleanups for no longer needed
        // (thus destroyed) directives.
        fixture.componentInstance.logins = ['c', 'd'];
        fixture.detectChanges();

        // Reset all spies again, prepare for next check.
        resetSpies(group, control);

        control.setValue('Updated value');

        verifySpies(control, {
          viewValidatorCallCount: 2,  // since now we have 2 items produced by *ngFor
          valueAccessorCallCount: 2,  // since now we have 2 items produced by *ngFor
          ownValidatorCallCount: 1,
          viewValidators: control,
          ownValidators: control,
          valueAccessor: 'Updated value',
          valueChanges: 'Updated value',
        });
        verifySpies(group, {
          viewValidators: group,
          ownValidators: group,
          valueChanges: {control: 'Updated value'},
        });

        // Case 3: hide form group and verify that no directive-related callbacks
        // (validators, value accessors) are invoked when we set control value later.
        fixture.componentInstance.visible = false;
        fixture.detectChanges();

        // Reset all spies again, prepare for next check.
        resetSpies(group, control);

        control.setValue('Updated value (v2)');

        verifySpies(control, {
          viewValidators: SHOULD_NOT_BE_CALLED,
          ownValidators: control,
          valueAccessor: SHOULD_NOT_BE_CALLED,
          valueChanges: 'Updated value (v2)',
        });
        verifySpies(group, {
          viewValidators: SHOULD_NOT_BE_CALLED,
          ownValidators: group,
          valueChanges: {control: 'Updated value (v2)'},
        });
      });

      it('should clean up when FormArrayName is destroyed (but parent FormGroup exists)', () => {
        // Scenario:
        // ---------
        // [formGroup]
        //   formArrayName
        //     formControlName *ngIf

        const control = new FormControl();
        addOwnValidatorsAndAttachSpies(control, {
          viewValidators: [ViewValidatorA, AsyncViewValidatorA],
          valueAccessor: ValueAccessorA,
        });

        const arr = new FormArray([control]);
        addOwnValidatorsAndAttachSpies(arr, {
          viewValidators: [ViewValidatorB, AsyncViewValidatorB],
        });

        const group = new FormGroup({arr});
        addOwnValidatorsAndAttachSpies(group, {
          viewValidators: [ViewValidatorC, AsyncViewValidatorC],
        });

        @Component({
          selector: 'app',
          template: `
            <div [formGroup]="group" validators-c>
              <ng-container formArrayName="arr" validators-b>
                <input *ngIf="visible" type="text" formControlName="0" cva-a validators-a>
              </ng-container>
            </div>
          `
        })
        class App {
          visible = true;
          group = group;
        }

        const fixture = initCleanupTest(App);

        resetSpies(group, arr, control);

        // Case 1: update control value and verify that all spies were called.
        control.setValue('Initial value');
        fixture.detectChanges();

        verifySpies(control, {
          viewValidators: control,
          ownValidators: control,
          valueAccessor: 'Initial value',
          valueChanges: 'Initial value',
        });
        verifySpies(arr, {
          viewValidators: arr,
          ownValidators: arr,
          valueChanges: ['Initial value'],
        });
        verifySpies(group, {
          viewValidators: group,
          ownValidators: group,
          valueChanges: {arr: ['Initial value']},
        });


        // Case 2: hide form group and verify that no directive-related callbacks
        // (validators, value accessors) are invoked when we set control value later.
        fixture.componentInstance.visible = false;
        fixture.detectChanges();

        // Reset all spies again, prepare for next check.
        resetSpies(group, arr, control);

        control.setValue('Updated value');

        // Expectation:
        // - `FormControlDirective` was destroyed, so connection to value accessor and view
        //   validators should also be destroyed.
        // - Own validators directly attached to FormGroup, FormArray and FormControl should still
        //   be invoked.
        // - `FormArrayName` was *not* destroyed, so all view validators should be invoked.
        verifySpies(control, {
          viewValidators: SHOULD_NOT_BE_CALLED,
          ownValidators: control,
          valueAccessor: SHOULD_NOT_BE_CALLED,
          valueChanges: 'Updated value',
        });
        verifySpies(arr, {
          viewValidators: arr,
          ownValidators: arr,
          valueChanges: ['Updated value'],
        });
        verifySpies(group, {
          viewValidators: group,
          ownValidators: group,
          valueChanges: {arr: ['Updated value']},
        });
      });

      it('should clean up when FormArrayName is destroyed (but parent FormGroup exists)', () => {
        // Scenario:
        // ---------
        // [formGroup]
        //   formArrayName *ngIf
        //     formControlName

        const control = new FormControl();
        addOwnValidatorsAndAttachSpies(control, {
          viewValidators: [ViewValidatorA, AsyncViewValidatorA],
          valueAccessor: ValueAccessorA,
        });

        const arr = new FormArray([control]);
        addOwnValidatorsAndAttachSpies(arr, {
          viewValidators: [ViewValidatorB, AsyncViewValidatorB],
        });

        const group = new FormGroup({arr});
        addOwnValidatorsAndAttachSpies(group, {
          viewValidators: [ViewValidatorC, AsyncViewValidatorC],
        });

        @Component({
          selector: 'app',
          template: `
            <div [formGroup]="group" validators-c>
              <ng-container *ngIf="visible" formArrayName="arr" validators-b>
                <input type="text" formControlName="0" cva-a validators-a>
              </ng-container>
            </div>
          `
        })
        class App {
          visible = true;
          group = group;
        }

        const fixture = initCleanupTest(App);

        resetSpies(group, arr, control);

        // Case 1: update control value and verify that all spies were called.
        control.setValue('Initial value');
        fixture.detectChanges();

        verifySpies(control, {
          viewValidators: control,
          ownValidators: control,
          valueAccessor: 'Initial value',
          valueChanges: 'Initial value',
        });
        verifySpies(arr, {
          viewValidators: arr,
          ownValidators: arr,
          valueChanges: ['Initial value'],
        });
        verifySpies(group, {
          viewValidators: group,
          ownValidators: group,
          valueChanges: {arr: ['Initial value']},
        });


        // Case 2: hide form group and verify that no directive-related callbacks
        // (validators, value accessors) are invoked when we set control value later.
        fixture.componentInstance.visible = false;
        fixture.detectChanges();

        // Reset all spies again, prepare for next check.
        resetSpies(group, arr, control);

        control.setValue('Updated value');

        // Expectation:
        // - `FormArrayName` was destroyed, so connection to view validators should be destroyed.
        // - Own validators directly attached to FormGroup, FormArray and FormControl should still
        //   be invoked.
        verifySpies(control, {
          viewValidators: SHOULD_NOT_BE_CALLED,
          ownValidators: control,
          valueAccessor: SHOULD_NOT_BE_CALLED,
          valueChanges: 'Updated value',
        });
        verifySpies(arr, {
          viewValidators: SHOULD_NOT_BE_CALLED,
          ownValidators: arr,
          valueChanges: ['Updated value'],
        });
        verifySpies(group, {
          viewValidators: group,
          ownValidators: group,
          valueChanges: {arr: ['Updated value']},
        });

        // Case 3: make the form array control available again and verify all callbacks are
        // correctly attached and invoked.
        fixture.componentInstance.visible = true;
        fixture.detectChanges();

        // Reset all spies again, prepare for next check.
        resetSpies(group, arr, control);

        control.setValue('Updated value (v2)');

        verifySpies(control, {
          viewValidators: control,
          ownValidators: control,
          valueAccessor: 'Updated value (v2)',
          valueChanges: 'Updated value (v2)',
        });
        verifySpies(arr, {
          viewValidators: arr,
          ownValidators: arr,
          valueChanges: ['Updated value (v2)'],
        });
        verifySpies(group, {
          viewValidators: group,
          ownValidators: group,
          valueChanges: {arr: ['Updated value (v2)']},
        });
      });

      it('should clean up all child controls when FormGroup is destroyed', () => {
        // Scenario:
        // ---------
        // [formGroup] *ngIf
        //   formArrayName
        //     formControlName

        const control = new FormControl();
        addOwnValidatorsAndAttachSpies(control, {
          viewValidators: [ViewValidatorA, AsyncViewValidatorA],
          valueAccessor: ValueAccessorA,
        });

        const arr = new FormArray([control]);
        addOwnValidatorsAndAttachSpies(arr, {
          viewValidators: [ViewValidatorB, AsyncViewValidatorB],
        });

        const group = new FormGroup({arr});
        addOwnValidatorsAndAttachSpies(group, {
          viewValidators: [ViewValidatorC, AsyncViewValidatorC],
        });

        @Component({
          selector: 'app',
          template: `
            <div [formGroup]="group" validators-c *ngIf="visible">
              <ng-container formArrayName="arr" validators-b>
                <input type="text" formControlName="0" cva-a validators-a>
              </ng-container>
            </div>
          `
        })
        class App {
          visible = true;
          group = group;
        }

        const fixture = initCleanupTest(App);

        resetSpies(group, arr, control);

        // Case 1: update control value and verify that all spies were called.
        control.setValue('Initial value');
        fixture.detectChanges();

        verifySpies(control, {
          viewValidators: control,
          ownValidators: control,
          valueAccessor: 'Initial value',
          valueChanges: 'Initial value',
        });
        verifySpies(arr, {
          viewValidators: arr,
          ownValidators: arr,
          valueChanges: ['Initial value'],
        });
        verifySpies(group, {
          viewValidators: group,
          ownValidators: group,
          valueChanges: {arr: ['Initial value']},
        });


        // Case 2: hide form group and verify that no directive-related callbacks
        // (validators, value accessors) are invoked when we set control value later.
        fixture.componentInstance.visible = false;
        fixture.detectChanges();

        // Reset all spies again, prepare for next check.
        resetSpies(group, arr, control);

        control.setValue('Updated value');

        // Expectation:
        // - `FormArrayName` was destroyed, so connection to view validators should be destroyed.
        // - Own validators directly attached to FormGroup, FormArray and FormControl should still
        //   be invoked.
        verifySpies(control, {
          viewValidators: SHOULD_NOT_BE_CALLED,
          ownValidators: control,
          valueAccessor: SHOULD_NOT_BE_CALLED,
          valueChanges: 'Updated value',
        });
        verifySpies(arr, {
          viewValidators: SHOULD_NOT_BE_CALLED,
          ownValidators: arr,
          valueChanges: ['Updated value'],
        });
        verifySpies(group, {
          viewValidators: SHOULD_NOT_BE_CALLED,
          ownValidators: group,
          valueChanges: {arr: ['Updated value']},
        });

        // Case 3: make the form group available again and verify all callbacks are correctly
        // attached and invoked.
        fixture.componentInstance.visible = true;
        fixture.detectChanges();

        // Reset all spies again, prepare for next check.
        resetSpies(group, arr, control);

        control.setValue('Updated value (v2)');

        verifySpies(control, {
          viewValidators: control,
          ownValidators: control,
          valueAccessor: 'Updated value (v2)',
          valueChanges: 'Updated value (v2)',
        });
        verifySpies(arr, {
          viewValidators: arr,
          ownValidators: arr,
          valueChanges: ['Updated value (v2)'],
        });
        verifySpies(group, {
          viewValidators: group,
          ownValidators: group,
          valueChanges: {arr: ['Updated value (v2)']},
        });
      });

      it('should clean up all child controls (with *ngFor) when FormArrayName is destroyed', () => {
        // Scenario:
        // ---------
        // [formGroup]
        //   formArrayName *ngIf
        //     formControlName *ngFor

        const controlA = new FormControl('A');
        addOwnValidatorsAndAttachSpies(controlA, {
          viewValidators: [ViewValidatorA, AsyncViewValidatorA],
          valueAccessor: ValueAccessorA,
        });

        const controlB = new FormControl('B');
        // Note: since ControlA and ControlB share the same set of validators and value accessor, we
        // add spies just ones while configuring ControlA (it's not possible to add spies multiple
        // times).
        addOwnValidatorsAndAttachSpies(controlB, {});

        const arr = new FormArray([controlA, controlB]);
        addOwnValidatorsAndAttachSpies(arr, {
          viewValidators: [ViewValidatorB, AsyncViewValidatorB],
        });

        const group = new FormGroup({arr});
        addOwnValidatorsAndAttachSpies(group, {
          viewValidators: [ViewValidatorC, AsyncViewValidatorC],
        });

        @Component({
          selector: 'app',
          template: `
            <div [formGroup]="group" validators-c>
              <ng-container formArrayName="arr" validators-b *ngIf="visible">
                <ng-container *ngFor="let i of ids">
                  <input type="text" [formControlName]="i" cva-a validators-a>
                </ng-container>
              </ng-container>
            </div>
          `
        })
        class App {
          visible = true;
          group = group;
          ids = [0, 1];
        }

        const fixture = initCleanupTest(App);

        resetSpies(group, arr, controlA, controlB);

        // Case 1: update control value and verify that all spies were called.
        controlA.setValue('Updated A');
        fixture.detectChanges();

        verifySpies(controlA, {
          viewValidators: controlA,
          ownValidators: controlA,
          valueAccessor: 'Updated A',
          valueChanges: 'Updated A',
        });
        verifySpies(controlB, {
          // ControlB is a sibling to ControlA, so updating ControlA has no effect on ControlB.
          viewValidators: SHOULD_NOT_BE_CALLED,
          ownValidators: SHOULD_NOT_BE_CALLED,
          valueAccessor: SHOULD_NOT_BE_CALLED,
          valueChanges: SHOULD_NOT_BE_CALLED,
        });
        verifySpies(arr, {
          viewValidators: arr,
          ownValidators: arr,
          valueChanges: ['Updated A', 'B'],
        });
        verifySpies(group, {
          viewValidators: group,
          ownValidators: group,
          valueChanges: {arr: ['Updated A', 'B']},
        });

        // Case 2: remove ControlA from the view by updating the list of ids.
        // Verify that ControlA is detached from the view, but ControlB still works.
        fixture.componentInstance.ids = [1];
        fixture.detectChanges();

        // Reset all spies again, prepare for next check.
        resetSpies(group, arr, controlA, controlB);

        controlA.setValue('Updated A (v2)');

        verifySpies(controlA, {
          viewValidators: SHOULD_NOT_BE_CALLED,
          ownValidators: controlA,
          valueAccessor: SHOULD_NOT_BE_CALLED,
          valueChanges: 'Updated A (v2)',
        });
        verifySpies(controlB, {
          viewValidators: SHOULD_NOT_BE_CALLED,
          ownValidators: SHOULD_NOT_BE_CALLED,
          valueAccessor: SHOULD_NOT_BE_CALLED,
          valueChanges: SHOULD_NOT_BE_CALLED,
        });
        verifySpies(arr, {
          viewValidators: arr,
          ownValidators: arr,
          valueChanges: ['Updated A (v2)', 'B'],
        });
        verifySpies(group, {
          viewValidators: group,
          ownValidators: group,
          valueChanges: {arr: ['Updated A (v2)', 'B']},
        });

        // Case 3: hide form group and verify that no directive-related callbacks
        // (validators, value accessors) are invoked when we set control value later.
        fixture.componentInstance.visible = false;
        fixture.detectChanges();

        // Reset all spies again, prepare for next check.
        resetSpies(group, arr, controlA, controlB);

        controlB.setValue('Updated B');

        // Expectation:
        // - `FormArrayName` was destroyed, so connection to view validators should be destroyed.
        // - Own validators directly attached to FormGroup, FormArray and FormControl should still
        //   be invoked.
        verifySpies(controlA, {
          viewValidators: SHOULD_NOT_BE_CALLED,
          ownValidators: SHOULD_NOT_BE_CALLED,
          valueAccessor: SHOULD_NOT_BE_CALLED,
          valueChanges: SHOULD_NOT_BE_CALLED,
        });
        verifySpies(controlB, {
          viewValidators: SHOULD_NOT_BE_CALLED,
          ownValidators: controlB,
          valueAccessor: SHOULD_NOT_BE_CALLED,
          valueChanges: 'Updated B',
        });
        verifySpies(arr, {
          viewValidators: SHOULD_NOT_BE_CALLED,
          ownValidators: arr,
          valueChanges: ['Updated A (v2)', 'Updated B'],
        });
        verifySpies(group, {
          viewValidators: group,
          ownValidators: group,
          valueChanges: {arr: ['Updated A (v2)', 'Updated B']},
        });
      });

      it('should clean up all child controls when FormGroupName is destroyed', () => {
        // Scenario:
        // ---------
        // [formGroup]
        //   formGroupName *ngIf
        //     formControlName

        const control = new FormControl();
        addOwnValidatorsAndAttachSpies(control, {
          viewValidators: [ViewValidatorA, AsyncViewValidatorA],
          valueAccessor: ValueAccessorA,
        });

        const group = new FormGroup({control});
        addOwnValidatorsAndAttachSpies(group, {
          viewValidators: [ViewValidatorB, AsyncViewValidatorB],
        });

        const root = new FormGroup({group});
        addOwnValidatorsAndAttachSpies(root, {
          viewValidators: [ViewValidatorC, AsyncViewValidatorC],
        });

        @Component({
          selector: 'app',
          template: `
            <div [formGroup]="root" validators-c>
              <ng-container formGroupName="group" validators-b *ngIf="visible">
                <input type="text" formControlName="control" cva-a validators-a>
              </ng-container>
            </div>
          `
        })
        class App {
          visible = true;
          root = root;
        }

        const fixture = initCleanupTest(App);

        resetSpies(root, group, control);

        // Case 1: update control value and verify that all spies were called.
        control.setValue('Initial value');
        fixture.detectChanges();

        verifySpies(control, {
          viewValidators: control,
          ownValidators: control,
          valueAccessor: 'Initial value',
          valueChanges: 'Initial value',
        });
        verifySpies(group, {
          viewValidators: group,
          ownValidators: group,
          valueChanges: {control: 'Initial value'},
        });
        verifySpies(root, {
          viewValidators: root,
          ownValidators: root,
          valueChanges: {group: {control: 'Initial value'}},
        });


        // Case 2: hide form group and verify that no directive-related callbacks
        // (validators, value accessors) are invoked when we set control value later.
        fixture.componentInstance.visible = false;
        fixture.detectChanges();

        // Reset all spies again, prepare for next check.
        resetSpies(root, group, control);

        control.setValue('Updated value');

        // Expectation:
        // - `FormGroupName` was destroyed, so connection to view validators should be destroyed.
        // - Own validators directly attached to FormGroups and FormControl should still
        //   be invoked.
        verifySpies(control, {
          viewValidators: SHOULD_NOT_BE_CALLED,
          ownValidators: control,
          valueAccessor: SHOULD_NOT_BE_CALLED,
          valueChanges: 'Updated value',
        });
        verifySpies(group, {
          viewValidators: SHOULD_NOT_BE_CALLED,
          ownValidators: group,
          valueChanges: {control: 'Updated value'},
        });
        verifySpies(root, {
          viewValidators: root,
          ownValidators: root,
          valueChanges: {group: {control: 'Updated value'}},
        });
      });

      it('should clean up all child controls when FormGroup is destroyed', () => {
        // Scenario:
        // ---------
        // [formGroup] *ngIf
        //   formGroupName
        //     formControlName

        const control = new FormControl();
        addOwnValidatorsAndAttachSpies(control, {
          viewValidators: [ViewValidatorA, AsyncViewValidatorA],
          valueAccessor: ValueAccessorA,
        });

        const group = new FormGroup({control});
        addOwnValidatorsAndAttachSpies(group, {
          viewValidators: [ViewValidatorB, AsyncViewValidatorB],
        });

        const root = new FormGroup({group});
        addOwnValidatorsAndAttachSpies(root, {
          viewValidators: [ViewValidatorC, AsyncViewValidatorC],
        });

        @Component({
          selector: 'app',
          template: `
            <div [formGroup]="root" validators-c *ngIf="visible">
              <ng-container formGroupName="group" validators-b>
                <input type="text" formControlName="control" cva-a validators-a>
              </ng-container>
            </div>
          `
        })
        class App {
          visible = true;
          root = root;
        }

        const fixture = initCleanupTest(App);

        resetSpies(root, group, control);

        // Case 1: update control value and verify that all spies were called.
        control.setValue('Initial value');
        fixture.detectChanges();

        verifySpies(control, {
          viewValidators: control,
          ownValidators: control,
          valueAccessor: 'Initial value',
          valueChanges: 'Initial value',
        });
        verifySpies(group, {
          viewValidators: group,
          ownValidators: group,
          valueChanges: {control: 'Initial value'},
        });
        verifySpies(root, {
          viewValidators: root,
          ownValidators: root,
          valueChanges: {group: {control: 'Initial value'}},
        });


        // Case 2: hide form group and verify that no directive-related callbacks
        // (validators, value accessors) are invoked when we set control value later.
        fixture.componentInstance.visible = false;
        fixture.detectChanges();

        // Reset all spies again, prepare for next check.
        resetSpies(root, group, control);

        control.setValue('Updated value');

        // Expectation:
        // - `FormGroup` was destroyed, so connection to view validators should be destroyed.
        // - Own validators directly attached to FormGroups and FormControl should still
        //   be invoked.
        verifySpies(control, {
          viewValidators: SHOULD_NOT_BE_CALLED,
          ownValidators: control,
          valueAccessor: SHOULD_NOT_BE_CALLED,
          valueChanges: 'Updated value',
        });
        verifySpies(group, {
          viewValidators: SHOULD_NOT_BE_CALLED,
          ownValidators: group,
          valueChanges: {control: 'Updated value'},
        });
        verifySpies(root, {
          viewValidators: SHOULD_NOT_BE_CALLED,
          ownValidators: root,
          valueChanges: {group: {control: 'Updated value'}},
        });
      });

      // See https://github.com/angular/angular/issues/40521.
      it('should properly clean up when FormControlName has no CVA', () => {
        @Component({
          selector: 'no-cva-compo',
          template: `
            <form [formGroup]="form">
              <div formControlName="control"></div>
            </form>
          `
        })
        class NoCVAComponent {
          form = new FormGroup({control: new FormControl()});
        }

        const fixture = initTest(NoCVAComponent);
        expect(() => {
          fixture.detectChanges();
        }).toThrowError('No value accessor for form control with name: \'control\'');

        // Making sure that cleanup between tests doesn't cause any issues
        // for not fully initialized controls.
        expect(() => {
          fixture.destroy();
        }).not.toThrow();
      });
    });
  });
}

/**
 * Creates an async validator using a checker function, a timeout and the error to emit in case of
 * validation failure
 *
 * @param checker A function to decide whether the validator will resolve with success or failure
 * @param timeout When the validation will resolve
 * @param error The error message to be emitted in case of validation failure
 *
 * @returns An async validator created using a checker function, a timeout and the error to emit in
 * case of validation failure
 */
function asyncValidator(
    checker: (c: AbstractControl) => boolean, timeout: number = 0, error: any = {
      'async': true
    }) {
  return (c: AbstractControl) => {
    let resolve: (result: any) => void;
    const promise = new Promise<any>(res => {
      resolve = res;
    });
    const res = checker(c) ? null : error;
    setTimeout(() => resolve(res), timeout);
    return promise;
  };
}

function uniqLoginAsyncValidator(expectedValue: string, timeout: number = 0) {
  return asyncValidator(c => c.value === expectedValue, timeout, {'uniqLogin': true});
}

function observableValidator(resultArr: number[]): AsyncValidatorFn {
  return (c: AbstractControl) => {
    return timer(100).pipe(tap((resp: any) => resultArr.push(resp)));
  };
}

function loginIsEmptyGroupValidator(c: FormGroup) {
  return c.controls['login'].value == '' ? {'loginIsEmpty': true} : null;
}

@Directive({
  selector: '[login-is-empty-validator]',
  providers: [{provide: NG_VALIDATORS, useValue: loginIsEmptyGroupValidator, multi: true}]
})
class LoginIsEmptyValidator {
}

@Directive({
  selector: '[uniq-login-validator]',
  providers: [
    {provide: NG_ASYNC_VALIDATORS, useExisting: forwardRef(() => UniqLoginValidator), multi: true}
  ]
})
class UniqLoginValidator implements AsyncValidator {
  @Input('uniq-login-validator') expected: any;

  validate(c: AbstractControl) {
    return uniqLoginAsyncValidator(this.expected)(c);
  }
}

@Component({selector: 'form-control-comp', template: `<input type="text" [formControl]="control">`})
class FormControlComp {
  // TODO(issue/24571): remove '!'.
  control!: FormControl;
}

@Component({
  selector: 'form-group-comp',
  template: `
    <form [formGroup]="form" (ngSubmit)="event=$event">
      <input type="text" formControlName="login">
    </form>`
})
class FormGroupComp {
  // TODO(issue/24571): remove '!'.
  control!: FormControl;
  // TODO(issue/24571): remove '!'.
  form!: FormGroup;
  // TODO(issue/24571): remove '!'.
  event!: Event;
}

@Component({
  selector: 'nested-form-group-comp',
  template: `
    <form [formGroup]="form">
      <div formGroupName="signin" login-is-empty-validator>
        <input formControlName="login">
        <input formControlName="password">
      </div>
      <input *ngIf="form.contains('email')" formControlName="email">
    </form>`
})
class NestedFormGroupComp {
  // TODO(issue/24571): remove '!'.
  form!: FormGroup;
}

@Component({
  selector: 'form-array-comp',
  template: `
    <form [formGroup]="form">
      <div formArrayName="cities">
        <div *ngFor="let city of cityArray.controls; let i=index">
          <input [formControlName]="i">
        </div>
      </div>
     </form>`
})
class FormArrayComp {
  // TODO(issue/24571): remove '!'.
  form!: FormGroup;
  // TODO(issue/24571): remove '!'.
  cityArray!: FormArray;
}

@Component({
  selector: 'form-array-nested-group',
  template: `
     <div [formGroup]="form">
      <div formArrayName="cities">
        <div *ngFor="let city of cityArray.controls; let i=index" [formGroupName]="i">
          <input formControlName="town">
          <input formControlName="state">
        </div>
      </div>
     </div>`
})
class FormArrayNestedGroup {
  // TODO(issue/24571): remove '!'.
  form!: FormGroup;
  // TODO(issue/24571): remove '!'.
  cityArray!: FormArray;
}

@Component({
  selector: 'form-group-ng-model',
  template: `
  <form [formGroup]="form">
    <input type="text" formControlName="login" [(ngModel)]="login">
    <input type="text" formControlName="password" [(ngModel)]="password">
   </form>`
})
class FormGroupNgModel {
  // TODO(issue/24571): remove '!'.
  form!: FormGroup;
  // TODO(issue/24571): remove '!'.
  login!: string;
  // TODO(issue/24571): remove '!'.
  password!: string;
}

@Component({
  selector: 'form-control-ng-model',
  template: `
    <input type="text" [formControl]="control" [(ngModel)]="login">
    <input type="text" [formControl]="passwordControl" [(ngModel)]="password">
  `
})
class FormControlNgModel {
  // TODO(issue/24571): remove '!'.
  control!: FormControl;
  // TODO(issue/24571): remove '!'.
  login!: string;
  // TODO(issue/24571): remove '!'.
  passwordControl!: FormControl;
  // TODO(issue/24571): remove '!'.
  password!: string;
}

@Component({
  selector: 'login-is-empty-wrapper',
  template: `
    <div [formGroup]="form" login-is-empty-validator>
      <input type="text" formControlName="login" required>
      <input type="text" formControlName="min" minlength="3">
      <input type="text" formControlName="max" maxlength="3">
      <input type="text" formControlName="pattern" pattern=".{3,}">
   </div>`
})
class LoginIsEmptyWrapper {
  // TODO(issue/24571): remove '!'.
  form!: FormGroup;
}

@Component({
  selector: 'validation-bindings-form',
  template: `
    <div [formGroup]="form">
      <input name="required" type="text" formControlName="login" [required]="required">
      <input name="minlength" type="text" formControlName="min" [minlength]="minLen">
      <input name="maxlength" type="text" formControlName="max" [maxlength]="maxLen">
      <input name="pattern" type="text" formControlName="pattern" [pattern]="pattern">
   </div>`
})
class ValidationBindingsForm {
  // TODO(issue/24571): remove '!'.
  form!: FormGroup;
  // TODO(issue/24571): remove '!'.
  required!: boolean;
  // TODO(issue/24571): remove '!'.
  minLen!: number;
  // TODO(issue/24571): remove '!'.
  maxLen!: number;
  // TODO(issue/24571): remove '!'.
  pattern!: string;
}

@Component({
  selector: 'form-control-checkbox-validator',
  template: `<input type="checkbox" [formControl]="control">`
})
class FormControlCheckboxRequiredValidator {
  // TODO(issue/24571): remove '!'.
  control!: FormControl;
}

@Component({
  selector: 'uniq-login-wrapper',
  template: `
  <div [formGroup]="form">
    <input type="text" formControlName="login" uniq-login-validator="expected">
  </div>`
})
class UniqLoginWrapper {
  // TODO(issue/24571): remove '!'.
  form!: FormGroup;
}

@Component({
  selector: 'form-group-with-validators',
  template: `
    <div [formGroup]="form" validators-a>
      <input type="text" formControlName="login">
    </div>
  `
})
class FormGroupWithValidators {
  form = new FormGroup({login: new FormControl('INITIAL')});
}

@Component({
  selector: 'form-control-with-validators',
  template: `
    <div [formGroup]="form">
      <input type="text" formControlName="login">
    </div>
  `
})
class FormControlWithAsyncValidatorFn {
  control = new FormControl('INITIAL');
  form = new FormGroup({login: this.control});

  constructor() {
    this.control.setAsyncValidators(() => {
      return NEVER.pipe(map((_: any) => ({timeoutError: true})));
    });
  }
}

@Component({
  selector: 'form-control-with-validators',
  template: `
    <div [formGroup]="form">
      <input type="text" formControlName="login" validators-a>
    </div>
  `
})
class FormControlWithValidators {
  form = new FormGroup({login: new FormControl('INITIAL')});
}

@Component({
  selector: 'ngfor-form-controls-with-validators',
  template: `
    <div [formGroup]="formA">
      <input type="radio" formControlName="login" validators-a>
    </div>
    <div [formGroup]="formB">
      <input type="text" formControlName="login" validators-a id="login">
    </div>
  `
})
class MultipleFormControls {
  control = new FormControl('a');
  formA = new FormGroup({login: this.control});
  formB = new FormGroup({login: this.control});
}

@Component({
  selector: 'ngfor-form-controls-with-validators',
  template: `
    <div [formGroup]="form">
      <ng-container *ngFor="let login of logins">
        <input type="radio" formControlName="login" [value]="login" validators-a>
      </ng-container>
    </div>
  `
})
class NgForFormControlWithValidators {
  form = new FormGroup({login: new FormControl('a')});
  logins = ['a', 'b', 'c'];
}

@Component({
  selector: 'min-max-form-control-name',
  template: `
    <div [formGroup]="form">
      <input type="number" formControlName="pin" [max]="max" [min]="min">
   </div>`
})
class MinMaxFormControlNameComp {
  control!: FormControl;
  form!: FormGroup;
  min: number|string = 1;
  max: number|string = 10;
}

@Component({
  selector: 'min-max-form-control',
  template: `
    <div [formGroup]="form">
      <input type="number" [formControl]="control" [max]="max" [min]="min">
   </div>`
})
class MinMaxFormControlComp {
  control!: FormControl;
  form!: FormGroup;
  min: number|string = 1;
  max: number|string = 10;
}