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

import {fakeAsync, tick} from '@angular/core/testing';
import {AsyncTestCompleter, beforeEach, describe, inject, it} from '@angular/core/testing/testing_internal';
import {AbstractControl, FormArray, FormControl, FormGroup} from '@angular/forms';

import {isPresent} from '../src/facade/lang';
import {Validators} from '../src/validators';

export function main() {
  function asyncValidator(expected: string, timeouts = {}) {
    return (c: AbstractControl) => {
      var resolve: (result: any) => void;
      var promise = new Promise(res => { resolve = res; });
      var t = isPresent((timeouts as any)[c.value]) ? (timeouts as any)[c.value] : 0;
      var res = c.value != expected ? {'async': true} : null;

      if (t == 0) {
        resolve(res);
      } else {
        setTimeout(() => { resolve(res); }, t);
      }

      return promise;
    };
  }

  describe('FormArray', () => {
    describe('adding/removing', () => {
      let a: FormArray;
      let c1: FormControl, c2: FormControl, c3: FormControl;

      beforeEach(() => {
        a = new FormArray([]);
        c1 = new FormControl(1);
        c2 = new FormControl(2);
        c3 = new FormControl(3);
      });

      it('should support pushing', () => {
        a.push(c1);
        expect(a.length).toEqual(1);
        expect(a.controls).toEqual([c1]);
      });

      it('should support removing', () => {
        a.push(c1);
        a.push(c2);
        a.push(c3);

        a.removeAt(1);

        expect(a.controls).toEqual([c1, c3]);
      });

      it('should support inserting', () => {
        a.push(c1);
        a.push(c3);

        a.insert(1, c2);

        expect(a.controls).toEqual([c1, c2, c3]);
      });
    });

    describe('value', () => {
      it('should be the reduced value of the child controls', () => {
        const a = new FormArray([new FormControl(1), new FormControl(2)]);
        expect(a.value).toEqual([1, 2]);
      });

      it('should be an empty array when there are no child controls', () => {
        const a = new FormArray([]);
        expect(a.value).toEqual([]);
      });
    });

    describe('setValue', () => {
      let c: FormControl, c2: FormControl, a: FormArray;

      beforeEach(() => {
        c = new FormControl('');
        c2 = new FormControl('');
        a = new FormArray([c, c2]);
      });

      it('should set its own value', () => {
        a.setValue(['one', 'two']);
        expect(a.value).toEqual(['one', 'two']);
      });

      it('should set child values', () => {
        a.setValue(['one', 'two']);
        expect(c.value).toEqual('one');
        expect(c2.value).toEqual('two');
      });

      it('should set values for disabled child controls', () => {
        c2.disable();
        a.setValue(['one', 'two']);
        expect(c2.value).toEqual('two');
        expect(a.value).toEqual(['one']);
        expect(a.getRawValue()).toEqual(['one', 'two']);
      });

      it('should set value for disabled arrays', () => {
        a.disable();
        a.setValue(['one', 'two']);
        expect(c.value).toEqual('one');
        expect(c2.value).toEqual('two');
        expect(a.value).toEqual(['one', 'two']);
      });

      it('should set parent values', () => {
        const form = new FormGroup({'parent': a});
        a.setValue(['one', 'two']);
        expect(form.value).toEqual({'parent': ['one', 'two']});
      });

      it('should throw if fields are missing from supplied value (subset)', () => {
        expect(() => a.setValue([, 'two']))
            .toThrowError(new RegExp(`Must supply a value for form control at index: 0`));
      });

      it('should throw if a value is provided for a missing control (superset)', () => {
        expect(() => a.setValue([
          'one', 'two', 'three'
        ])).toThrowError(new RegExp(`Cannot find form control at index 2`));
      });

      it('should throw if a value is not provided for a disabled control', () => {
        c2.disable();
        expect(() => a.setValue(['one']))
            .toThrowError(new RegExp(`Must supply a value for form control at index: 1`));
      });

      it('should throw if no controls are set yet', () => {
        const empty = new FormArray([]);
        expect(() => empty.setValue(['one']))
            .toThrowError(new RegExp(`no form controls registered with this array`));
      });

      describe('setValue() events', () => {
        let form: FormGroup;
        let logger: any[];

        beforeEach(() => {
          form = new FormGroup({'parent': a});
          logger = [];
        });

        it('should emit one valueChange event per control', () => {
          form.valueChanges.subscribe(() => logger.push('form'));
          a.valueChanges.subscribe(() => logger.push('array'));
          c.valueChanges.subscribe(() => logger.push('control1'));
          c2.valueChanges.subscribe(() => logger.push('control2'));

          a.setValue(['one', 'two']);
          expect(logger).toEqual(['control1', 'control2', 'array', 'form']);
        });

        it('should emit one statusChange event per control', () => {
          form.statusChanges.subscribe(() => logger.push('form'));
          a.statusChanges.subscribe(() => logger.push('array'));
          c.statusChanges.subscribe(() => logger.push('control1'));
          c2.statusChanges.subscribe(() => logger.push('control2'));

          a.setValue(['one', 'two']);
          expect(logger).toEqual(['control1', 'control2', 'array', 'form']);
        });
      });
    });

    describe('patchValue', () => {
      let c: FormControl, c2: FormControl, a: FormArray;

      beforeEach(() => {
        c = new FormControl('');
        c2 = new FormControl('');
        a = new FormArray([c, c2]);
      });

      it('should set its own value', () => {
        a.patchValue(['one', 'two']);
        expect(a.value).toEqual(['one', 'two']);
      });

      it('should set child values', () => {
        a.patchValue(['one', 'two']);
        expect(c.value).toEqual('one');
        expect(c2.value).toEqual('two');
      });

      it('should patch disabled control values', () => {
        c2.disable();
        a.patchValue(['one', 'two']);
        expect(c2.value).toEqual('two');
        expect(a.value).toEqual(['one']);
        expect(a.getRawValue()).toEqual(['one', 'two']);
      });

      it('should patch disabled control arrays', () => {
        a.disable();
        a.patchValue(['one', 'two']);
        expect(c.value).toEqual('one');
        expect(c2.value).toEqual('two');
        expect(a.value).toEqual(['one', 'two']);
      });

      it('should set parent values', () => {
        const form = new FormGroup({'parent': a});
        a.patchValue(['one', 'two']);
        expect(form.value).toEqual({'parent': ['one', 'two']});
      });

      it('should ignore fields that are missing from supplied value (subset)', () => {
        a.patchValue([, 'two']);
        expect(a.value).toEqual(['', 'two']);
      });

      it('should not ignore fields that are null', () => {
        a.patchValue([null]);
        expect(a.value).toEqual([null, '']);
      });

      it('should ignore any value provided for a missing control (superset)', () => {
        a.patchValue([, , 'three']);
        expect(a.value).toEqual(['', '']);
      });

      describe('patchValue() events', () => {
        let form: FormGroup;
        let logger: any[];

        beforeEach(() => {
          form = new FormGroup({'parent': a});
          logger = [];
        });

        it('should emit one valueChange event per control', () => {
          form.valueChanges.subscribe(() => logger.push('form'));
          a.valueChanges.subscribe(() => logger.push('array'));
          c.valueChanges.subscribe(() => logger.push('control1'));
          c2.valueChanges.subscribe(() => logger.push('control2'));

          a.patchValue(['one', 'two']);
          expect(logger).toEqual(['control1', 'control2', 'array', 'form']);
        });

        it('should not emit valueChange events for skipped controls', () => {
          form.valueChanges.subscribe(() => logger.push('form'));
          a.valueChanges.subscribe(() => logger.push('array'));
          c.valueChanges.subscribe(() => logger.push('control1'));
          c2.valueChanges.subscribe(() => logger.push('control2'));

          a.patchValue(['one']);
          expect(logger).toEqual(['control1', 'array', 'form']);
        });

        it('should emit one statusChange event per control', () => {
          form.statusChanges.subscribe(() => logger.push('form'));
          a.statusChanges.subscribe(() => logger.push('array'));
          c.statusChanges.subscribe(() => logger.push('control1'));
          c2.statusChanges.subscribe(() => logger.push('control2'));

          a.patchValue(['one', 'two']);
          expect(logger).toEqual(['control1', 'control2', 'array', 'form']);
        });
      });
    });

    describe('reset()', () => {
      let c: FormControl, c2: FormControl, a: FormArray;

      beforeEach(() => {
        c = new FormControl('initial value');
        c2 = new FormControl('');
        a = new FormArray([c, c2]);
      });

      it('should set its own value if value passed', () => {
        a.setValue(['new value', 'new value']);

        a.reset(['initial value', '']);
        expect(a.value).toEqual(['initial value', '']);
      });

      it('should set its own value if boxed value passed', () => {
        a.setValue(['new value', 'new value']);

        a.reset([{value: 'initial value', disabled: false}, '']);
        expect(a.value).toEqual(['initial value', '']);
      });

      it('should clear its own value if no value passed', () => {
        a.setValue(['new value', 'new value']);

        a.reset();
        expect(a.value).toEqual([null, null]);
      });

      it('should set the value of each of its child controls if value passed', () => {
        a.setValue(['new value', 'new value']);

        a.reset(['initial value', '']);
        expect(c.value).toBe('initial value');
        expect(c2.value).toBe('');
      });

      it('should clear the value of each of its child controls if no value', () => {
        a.setValue(['new value', 'new value']);

        a.reset();
        expect(c.value).toBe(null);
        expect(c2.value).toBe(null);
      });

      it('should set the value of its parent if value passed', () => {
        const form = new FormGroup({'a': a});
        a.setValue(['new value', 'new value']);

        a.reset(['initial value', '']);
        expect(form.value).toEqual({'a': ['initial value', '']});
      });

      it('should clear the value of its parent if no value passed', () => {
        const form = new FormGroup({'a': a});
        a.setValue(['new value', 'new value']);

        a.reset();
        expect(form.value).toEqual({'a': [null, null]});
      });

      it('should mark itself as pristine', () => {
        a.markAsDirty();
        expect(a.pristine).toBe(false);

        a.reset();
        expect(a.pristine).toBe(true);
      });

      it('should mark all child controls as pristine', () => {
        c.markAsDirty();
        c2.markAsDirty();
        expect(c.pristine).toBe(false);
        expect(c2.pristine).toBe(false);

        a.reset();
        expect(c.pristine).toBe(true);
        expect(c2.pristine).toBe(true);
      });

      it('should mark the parent as pristine if all siblings pristine', () => {
        const c3 = new FormControl('');
        const form = new FormGroup({'a': a, 'c3': c3});

        a.markAsDirty();
        expect(form.pristine).toBe(false);

        a.reset();
        expect(form.pristine).toBe(true);
      });

      it('should not mark the parent pristine if any dirty siblings', () => {
        const c3 = new FormControl('');
        const form = new FormGroup({'a': a, 'c3': c3});

        a.markAsDirty();
        c3.markAsDirty();
        expect(form.pristine).toBe(false);

        a.reset();
        expect(form.pristine).toBe(false);
      });

      it('should mark itself as untouched', () => {
        a.markAsTouched();
        expect(a.untouched).toBe(false);

        a.reset();
        expect(a.untouched).toBe(true);
      });

      it('should mark all child controls as untouched', () => {
        c.markAsTouched();
        c2.markAsTouched();
        expect(c.untouched).toBe(false);
        expect(c2.untouched).toBe(false);

        a.reset();
        expect(c.untouched).toBe(true);
        expect(c2.untouched).toBe(true);
      });

      it('should mark the parent untouched if all siblings untouched', () => {
        const c3 = new FormControl('');
        const form = new FormGroup({'a': a, 'c3': c3});

        a.markAsTouched();
        expect(form.untouched).toBe(false);

        a.reset();
        expect(form.untouched).toBe(true);
      });

      it('should not mark the parent untouched if any touched siblings', () => {
        const c3 = new FormControl('');
        const form = new FormGroup({'a': a, 'c3': c3});

        a.markAsTouched();
        c3.markAsTouched();
        expect(form.untouched).toBe(false);

        a.reset();
        expect(form.untouched).toBe(false);
      });

      it('should retain previous disabled state', () => {
        a.disable();
        a.reset();

        expect(a.disabled).toBe(true);
      });

      it('should set child disabled state if boxed value passed', () => {
        a.disable();
        a.reset([{value: '', disabled: false}, '']);

        expect(c.disabled).toBe(false);
        expect(a.disabled).toBe(false);
      });


      describe('reset() events', () => {
        let form: FormGroup, c3: FormControl, logger: any[];

        beforeEach(() => {
          c3 = new FormControl('');
          form = new FormGroup({'a': a, 'c3': c3});
          logger = [];
        });

        it('should emit one valueChange event per reset control', () => {
          form.valueChanges.subscribe(() => logger.push('form'));
          a.valueChanges.subscribe(() => logger.push('array'));
          c.valueChanges.subscribe(() => logger.push('control1'));
          c2.valueChanges.subscribe(() => logger.push('control2'));
          c3.valueChanges.subscribe(() => logger.push('control3'));

          a.reset();
          expect(logger).toEqual(['control1', 'control2', 'array', 'form']);
        });

        it('should emit one statusChange event per reset control', () => {
          form.statusChanges.subscribe(() => logger.push('form'));
          a.statusChanges.subscribe(() => logger.push('array'));
          c.statusChanges.subscribe(() => logger.push('control1'));
          c2.statusChanges.subscribe(() => logger.push('control2'));
          c3.statusChanges.subscribe(() => logger.push('control3'));

          a.reset();
          expect(logger).toEqual(['control1', 'control2', 'array', 'form']);
        });
      });
    });

    describe('errors', () => {
      it('should run the validator when the value changes', () => {
        const simpleValidator = (c: FormArray) =>
            c.controls[0].value != 'correct' ? {'broken': true} : null;

        var c = new FormControl(null);
        var g = new FormArray([c], simpleValidator);

        c.setValue('correct');

        expect(g.valid).toEqual(true);
        expect(g.errors).toEqual(null);

        c.setValue('incorrect');

        expect(g.valid).toEqual(false);
        expect(g.errors).toEqual({'broken': true});
      });
    });


    describe('dirty', () => {
      let c: FormControl;
      let a: FormArray;

      beforeEach(() => {
        c = new FormControl('value');
        a = new FormArray([c]);
      });

      it('should be false after creating a control', () => { expect(a.dirty).toEqual(false); });

      it('should be true after changing the value of the control', () => {
        c.markAsDirty();

        expect(a.dirty).toEqual(true);
      });
    });

    describe('touched', () => {
      let c: FormControl;
      let a: FormArray;

      beforeEach(() => {
        c = new FormControl('value');
        a = new FormArray([c]);
      });

      it('should be false after creating a control', () => { expect(a.touched).toEqual(false); });

      it('should be true after child control is marked as touched', () => {
        c.markAsTouched();

        expect(a.touched).toEqual(true);
      });
    });


    describe('pending', () => {
      let c: FormControl;
      let a: FormArray;

      beforeEach(() => {
        c = new FormControl('value');
        a = new FormArray([c]);
      });

      it('should be false after creating a control', () => {
        expect(c.pending).toEqual(false);
        expect(a.pending).toEqual(false);
      });

      it('should be true after changing the value of the control', () => {
        c.markAsPending();

        expect(c.pending).toEqual(true);
        expect(a.pending).toEqual(true);
      });

      it('should not update the parent when onlySelf = true', () => {
        c.markAsPending({onlySelf: true});

        expect(c.pending).toEqual(true);
        expect(a.pending).toEqual(false);
      });
    });

    describe('valueChanges', () => {
      let a: FormArray;
      let c1: any /** TODO #9100 */, c2: any /** TODO #9100 */;

      beforeEach(() => {
        c1 = new FormControl('old1');
        c2 = new FormControl('old2');
        a = new FormArray([c1, c2]);
      });

      it('should fire an event after the value has been updated',
         inject([AsyncTestCompleter], (async: AsyncTestCompleter) => {
           a.valueChanges.subscribe({
             next: (value: any) => {
               expect(a.value).toEqual(['new1', 'old2']);
               expect(value).toEqual(['new1', 'old2']);
               async.done();
             }
           });
           c1.setValue('new1');
         }));

      it('should fire an event after the control\'s observable fired an event',
         inject([AsyncTestCompleter], (async: AsyncTestCompleter) => {
           var controlCallbackIsCalled = false;


           c1.valueChanges.subscribe({next: (value: any) => { controlCallbackIsCalled = true; }});

           a.valueChanges.subscribe({
             next: (value: any) => {
               expect(controlCallbackIsCalled).toBe(true);
               async.done();
             }
           });

           c1.setValue('new1');
         }));

      it('should fire an event when a control is removed',
         inject([AsyncTestCompleter], (async: AsyncTestCompleter) => {
           a.valueChanges.subscribe({
             next: (value: any) => {
               expect(value).toEqual(['old1']);
               async.done();
             }
           });

           a.removeAt(1);
         }));

      it('should fire an event when a control is added',
         inject([AsyncTestCompleter], (async: AsyncTestCompleter) => {
           a.removeAt(1);

           a.valueChanges.subscribe({
             next: (value: any) => {
               expect(value).toEqual(['old1', 'old2']);
               async.done();
             }
           });

           a.push(c2);
         }));
    });

    describe('get', () => {
      it('should return null when path is null', () => {
        const g = new FormGroup({});
        expect(g.get(null)).toEqual(null);
      });

      it('should return null when path is empty', () => {
        const g = new FormGroup({});
        expect(g.get([])).toEqual(null);
      });

      it('should return null when path is invalid', () => {
        const g = new FormGroup({});
        expect(g.get('invalid')).toEqual(null);
      });

      it('should return a child of a control group', () => {
        const g = new FormGroup({
          'one': new FormControl('111'),
          'nested': new FormGroup({'two': new FormControl('222')})
        });

        expect(g.get(['one']).value).toEqual('111');
        expect(g.get('one').value).toEqual('111');
        expect(g.get(['nested', 'two']).value).toEqual('222');
        expect(g.get('nested.two').value).toEqual('222');
      });

      it('should return an element of an array', () => {
        const g = new FormGroup({'array': new FormArray([new FormControl('111')])});

        expect(g.get(['array', 0]).value).toEqual('111');
      });
    });

    describe('asyncValidator', () => {
      it('should run the async validator', fakeAsync(() => {
           const c = new FormControl('value');
           const g = new FormArray([c], null, asyncValidator('expected'));

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

           tick(1);

           expect(g.errors).toEqual({'async': true});
           expect(g.pending).toEqual(false);
         }));
    });

    describe('disable() & enable()', () => {
      let a: FormArray;
      let c: FormControl;
      let c2: FormControl;

      beforeEach(() => {
        c = new FormControl(null);
        c2 = new FormControl(null);
        a = new FormArray([c, c2]);
      });

      it('should mark the array as disabled', () => {
        expect(a.disabled).toBe(false);
        expect(a.valid).toBe(true);

        a.disable();
        expect(a.disabled).toBe(true);
        expect(a.valid).toBe(false);

        a.enable();
        expect(a.disabled).toBe(false);
        expect(a.valid).toBe(true);
      });

      it('should set the array status as disabled', () => {
        expect(a.status).toBe('VALID');

        a.disable();
        expect(a.status).toBe('DISABLED');

        a.enable();
        expect(a.status).toBe('VALID');
      });

      it('should mark children of the array as disabled', () => {
        expect(c.disabled).toBe(false);
        expect(c2.disabled).toBe(false);

        a.disable();
        expect(c.disabled).toBe(true);
        expect(c2.disabled).toBe(true);

        a.enable();
        expect(c.disabled).toBe(false);
        expect(c2.disabled).toBe(false);
      });

      it('should ignore disabled controls in validation', () => {
        const g = new FormGroup({
          nested: new FormArray([new FormControl(null, Validators.required)]),
          two: new FormControl('two')
        });
        expect(g.valid).toBe(false);

        g.get('nested').disable();
        expect(g.valid).toBe(true);

        g.get('nested').enable();
        expect(g.valid).toBe(false);
      });

      it('should ignore disabled controls when serializing value', () => {
        const g = new FormGroup(
            {nested: new FormArray([new FormControl('one')]), two: new FormControl('two')});
        expect(g.value).toEqual({'nested': ['one'], 'two': 'two'});

        g.get('nested').disable();
        expect(g.value).toEqual({'two': 'two'});

        g.get('nested').enable();
        expect(g.value).toEqual({'nested': ['one'], 'two': 'two'});
      });

      it('should ignore disabled controls when determining dirtiness', () => {
        const g = new FormGroup({nested: a, two: new FormControl('two')});
        g.get(['nested', 0]).markAsDirty();
        expect(g.dirty).toBe(true);

        g.get('nested').disable();
        expect(g.get('nested').dirty).toBe(true);
        expect(g.dirty).toEqual(false);

        g.get('nested').enable();
        expect(g.dirty).toEqual(true);
      });

      it('should ignore disabled controls when determining touched state', () => {
        const g = new FormGroup({nested: a, two: new FormControl('two')});
        g.get(['nested', 0]).markAsTouched();
        expect(g.touched).toBe(true);

        g.get('nested').disable();
        expect(g.get('nested').touched).toBe(true);
        expect(g.touched).toEqual(false);

        g.get('nested').enable();
        expect(g.touched).toEqual(true);
      });

      it('should keep empty, disabled arrays disabled when updating validity', () => {
        const arr = new FormArray([]);
        expect(arr.status).toEqual('VALID');

        arr.disable();
        expect(arr.status).toEqual('DISABLED');

        arr.updateValueAndValidity();
        expect(arr.status).toEqual('DISABLED');

        arr.push(new FormControl({value: '', disabled: true}));
        expect(arr.status).toEqual('DISABLED');

        arr.push(new FormControl());
        expect(arr.status).toEqual('VALID');
      });

      it('should re-enable empty, disabled arrays', () => {
        const arr = new FormArray([]);
        arr.disable();
        expect(arr.status).toEqual('DISABLED');

        arr.enable();
        expect(arr.status).toEqual('VALID');
      });

      it('should not run validators on disabled controls', () => {
        const validator = jasmine.createSpy('validator');
        const arr = new FormArray([new FormControl()], validator);
        expect(validator.calls.count()).toEqual(1);

        arr.disable();
        expect(validator.calls.count()).toEqual(1);

        arr.setValue(['value']);
        expect(validator.calls.count()).toEqual(1);

        arr.enable();
        expect(validator.calls.count()).toEqual(2);
      });

      describe('disabled errors', () => {
        it('should clear out array errors when disabled', () => {
          const arr = new FormArray([new FormControl()], () => ({'expected': true}));
          expect(arr.errors).toEqual({'expected': true});

          arr.disable();
          expect(arr.errors).toEqual(null);

          arr.enable();
          expect(arr.errors).toEqual({'expected': true});
        });

        it('should re-populate array errors when enabled from a child', () => {
          const arr = new FormArray([new FormControl()], () => ({'expected': true}));
          arr.disable();
          expect(arr.errors).toEqual(null);

          arr.push(new FormControl());
          expect(arr.errors).toEqual({'expected': true});
        });

        it('should clear out async array errors when disabled', fakeAsync(() => {
             const arr = new FormArray([new FormControl()], null, asyncValidator('expected'));
             tick();
             expect(arr.errors).toEqual({'async': true});

             arr.disable();
             expect(arr.errors).toEqual(null);

             arr.enable();
             tick();
             expect(arr.errors).toEqual({'async': true});
           }));

        it('should re-populate async array errors when enabled from a child', fakeAsync(() => {
             const arr = new FormArray([new FormControl()], null, asyncValidator('expected'));
             tick();
             expect(arr.errors).toEqual({'async': true});

             arr.disable();
             expect(arr.errors).toEqual(null);

             arr.push(new FormControl());
             tick();
             expect(arr.errors).toEqual({'async': true});
           }));
      });

      describe('disabled events', () => {
        let logger: string[];
        let c: FormControl;
        let a: FormArray;
        let form: FormGroup;

        beforeEach(() => {
          logger = [];
          c = new FormControl('', Validators.required);
          a = new FormArray([c]);
          form = new FormGroup({a: a});
        });

        it('should emit value change events in the right order', () => {
          c.valueChanges.subscribe(() => logger.push('control'));
          a.valueChanges.subscribe(() => logger.push('array'));
          form.valueChanges.subscribe(() => logger.push('form'));

          a.disable();
          expect(logger).toEqual(['control', 'array', 'form']);
        });

        it('should emit status change events in the right order', () => {
          c.statusChanges.subscribe(() => logger.push('control'));
          a.statusChanges.subscribe(() => logger.push('array'));
          form.statusChanges.subscribe(() => logger.push('form'));

          a.disable();
          expect(logger).toEqual(['control', 'array', 'form']);
        });

      });

      describe('setControl()', () => {
        let c: FormControl;
        let a: FormArray;

        beforeEach(() => {
          c = new FormControl('one');
          a = new FormArray([c]);
        });

        it('should replace existing control with new control', () => {
          const c2 = new FormControl('new!', Validators.minLength(10));
          a.setControl(0, c2);

          expect(a.controls[0]).toEqual(c2);
          expect(a.value).toEqual(['new!']);
          expect(a.valid).toBe(false);
        });

        it('should add control if control did not exist before', () => {
          const c2 = new FormControl('new!', Validators.minLength(10));
          a.setControl(1, c2);

          expect(a.controls[1]).toEqual(c2);
          expect(a.value).toEqual(['one', 'new!']);
          expect(a.valid).toBe(false);
        });

        it('should remove control if new control is null', () => {
          a.setControl(0, null);
          expect(a.controls[0]).not.toBeDefined();
          expect(a.value).toEqual([]);
        });

        it('should only emit value change event once', () => {
          const logger: string[] = [];
          const c2 = new FormControl('new!');
          a.valueChanges.subscribe(() => logger.push('change!'));
          a.setControl(0, c2);
          expect(logger).toEqual(['change!']);
        });

      });

    });
  });
}