feat(forms): introduce min and max validators (#39063)

This commit adds the missing `min` and `max` validators.

BREAKING CHANGE:

Previously `min` and `max` attributes defined on the `<input type="number">`
were ignored by Forms module. Now presence of these attributes would
trigger min/max validation logic (in case `formControl`, `formControlName`
or `ngModel` directives are also present on a given input) and
corresponding form control status would reflect that.

Fixes #16352

PR Close #39063

goldens/public-api/forms/forms.d.ts

@@ -337,6 +337,11 @@ export declare class MaxLengthValidator implements Validator, OnChanges {
     validate(control: AbstractControl): ValidationErrors | null;
 }
 
+export declare class MaxValidator extends AbstractValidatorDirective implements OnChanges {
+    max: string | number;
+    ngOnChanges(changes: SimpleChanges): void;
+}
+
 export declare class MinLengthValidator implements Validator, OnChanges {
     minlength: string | number;
     ngOnChanges(changes: SimpleChanges): void;
@@ -344,6 +349,11 @@ export declare class MinLengthValidator implements Validator, OnChanges {
     validate(control: AbstractControl): ValidationErrors | null;
 }
 
+export declare class MinValidator extends AbstractValidatorDirective implements OnChanges {
+    min: string | number;
+    ngOnChanges(changes: SimpleChanges): void;
+}
+
 export declare const NG_ASYNC_VALIDATORS: InjectionToken<(Function | Validator)[]>;
 
 export declare const NG_VALIDATORS: InjectionToken<(Function | Validator)[]>;

packages/forms/src/directives.ts

@@ -24,7 +24,7 @@ import {FormGroupDirective} from './directives/reactive_directives/form_group_di
 import {FormArrayName, FormGroupName} from './directives/reactive_directives/form_group_name';
 import {NgSelectOption, SelectControlValueAccessor} from './directives/select_control_value_accessor';
 import {NgSelectMultipleOption, SelectMultipleControlValueAccessor} from './directives/select_multiple_control_value_accessor';
-import {CheckboxRequiredValidator, EmailValidator, MaxLengthValidator, MinLengthValidator, PatternValidator, RequiredValidator} from './directives/validators';
+import {CheckboxRequiredValidator, EmailValidator, MaxLengthValidator, MaxValidator, MinLengthValidator, MinValidator, PatternValidator, RequiredValidator} from './directives/validators';
 
 export {CheckboxControlValueAccessor} from './directives/checkbox_value_accessor';
 export {ControlValueAccessor} from './directives/control_value_accessor';
@@ -63,6 +63,8 @@ export const SHARED_FORM_DIRECTIVES: Type<any>[] = [
   PatternValidator,
   CheckboxRequiredValidator,
   EmailValidator,
+  MinValidator,
+  MaxValidator,
 ];
 
 export const TEMPLATE_DRIVEN_DIRECTIVES: Type<any>[] = [NgModel, NgModelGroup, NgForm];

packages/forms/src/directives/validators.ts

@@ -69,6 +69,189 @@ export interface Validator {
   registerOnValidatorChange?(fn: () => void): void;
 }
 
+/**
+ * A base class for Validator-based Directives. The class contains common logic shared across such
+ * Directives.
+ *
+ * For internal use only, this class is not intended for use outside of the Forms package.
+ */
+@Directive()
+abstract class AbstractValidatorDirective implements Validator {
+  private _validator: ValidatorFn = Validators.nullValidator;
+  private _onChange!: () => void;
+
+  /**
+   * Name of an input that matches directive selector attribute (e.g. `minlength` for
+   * `MinLengthDirective`). An input with a given name might contain configuration information (like
+   * `minlength='10'`) or a flag that indicates whether validator should be enabled (like
+   * `[required]='false'`).
+   *
+   * @internal
+   */
+  abstract inputName: string;
+
+  /**
+   * Creates an instance of a validator (specific to a directive that extends this base class).
+   *
+   * @internal
+   */
+  abstract createValidator(input: unknown): ValidatorFn;
+
+  /**
+   * Performs the necessary input normalization based on a specific logic of a Directive.
+   * For example, the function might be used to convert string-based representation of the
+   * `minlength` input to an integer value that can later be used in the `Validators.minLength`
+   * validator.
+   *
+   * @internal
+   */
+  abstract normalizeInput(input: unknown): unknown;
+
+  /**
+   * Helper function invoked from child classes to process changes (from `ngOnChanges` hook).
+   * @nodoc
+   */
+  handleChanges(changes: SimpleChanges): void {
+    if (this.inputName in changes) {
+      const input = this.normalizeInput(changes[this.inputName].currentValue);
+      this._validator = this.createValidator(input);
+      if (this._onChange) {
+        this._onChange();
+      }
+    }
+  }
+
+  /** @nodoc */
+  validate(control: AbstractControl): ValidationErrors|null {
+    return this._validator(control);
+  }
+
+  /** @nodoc */
+  registerOnValidatorChange(fn: () => void): void {
+    this._onChange = fn;
+  }
+}
+
+/**
+ * @description
+ * Provider which adds `MaxValidator` to the `NG_VALIDATORS` multi-provider list.
+ */
+export const MAX_VALIDATOR: StaticProvider = {
+  provide: NG_VALIDATORS,
+  useExisting: forwardRef(() => MaxValidator),
+  multi: true
+};
+
+/**
+ * A directive which installs the {@link MaxValidator} for any `formControlName`,
+ * `formControl`, or control with `ngModel` that also has a `max` attribute.
+ *
+ * @see [Form Validation](guide/form-validation)
+ *
+ * @usageNotes
+ *
+ * ### Adding a max validator
+ *
+ * The following example shows how to add a max validator to an input attached to an
+ * ngModel binding.
+ *
+ * ```html
+ * <input type="number" ngModel max="4">
+ * ```
+ *
+ * @ngModule ReactiveFormsModule
+ * @ngModule FormsModule
+ * @publicApi
+ */
+@Directive({
+  selector:
+      'input[type=number][max][formControlName],input[type=number][max][formControl],input[type=number][max][ngModel]',
+  providers: [MAX_VALIDATOR],
+  host: {'[attr.max]': 'max ? max : null'}
+})
+export class MaxValidator extends AbstractValidatorDirective implements OnChanges {
+  /**
+   * @description
+   * Tracks changes to the max bound to this directive.
+   */
+  @Input() max!: string|number;
+  /** @internal */
+  inputName = 'max';
+  /** @internal */
+  normalizeInput = (input: string): number => parseInt(input, 10);
+  /** @internal */
+  createValidator = (max: number): ValidatorFn => Validators.max(max);
+  /**
+   * Declare `ngOnChanges` lifecycle hook at the main directive level (vs keeping it in base class)
+   * to avoid differences in handling inheritance of lifecycle hooks between Ivy and ViewEngine in
+   * AOT mode. This could be refactored once ViewEngine is removed.
+   * @nodoc
+   */
+  ngOnChanges(changes: SimpleChanges): void {
+    this.handleChanges(changes);
+  }
+}
+
+/**
+ * @description
+ * Provider which adds `MinValidator` to the `NG_VALIDATORS` multi-provider list.
+ */
+export const MIN_VALIDATOR: StaticProvider = {
+  provide: NG_VALIDATORS,
+  useExisting: forwardRef(() => MinValidator),
+  multi: true
+};
+
+/**
+ * A directive which installs the {@link MinValidator} for any `formControlName`,
+ * `formControl`, or control with `ngModel` that also has a `min` attribute.
+ *
+ * @see [Form Validation](guide/form-validation)
+ *
+ * @usageNotes
+ *
+ * ### Adding a min validator
+ *
+ * The following example shows how to add a min validator to an input attached to an
+ * ngModel binding.
+ *
+ * ```html
+ * <input type="number" ngModel min="4">
+ * ```
+ *
+ * @ngModule ReactiveFormsModule
+ * @ngModule FormsModule
+ * @publicApi
+ */
+@Directive({
+  selector:
+      'input[type=number][min][formControlName],input[type=number][min][formControl],input[type=number][min][ngModel]',
+  providers: [MIN_VALIDATOR],
+  host: {'[attr.min]': 'min ? min : null'}
+})
+export class MinValidator extends AbstractValidatorDirective implements OnChanges {
+  /**
+   * @description
+   * Tracks changes to the min bound to this directive.
+   */
+  @Input() min!: string|number;
+  /** @internal */
+  inputName = 'min';
+  /** @internal */
+  normalizeInput = (input: string): number => parseInt(input, 10);
+  /** @internal */
+  createValidator = (min: number): ValidatorFn => Validators.min(min);
+  /**
+   * Declare `ngOnChanges` lifecycle hook at the main directive level (vs keeping it in base class)
+   * to avoid differences in handling inheritance of lifecycle hooks between Ivy and ViewEngine in
+   * AOT mode. This could be refactored once ViewEngine is removed.
+   * @nodoc
+   */
+  ngOnChanges(changes: SimpleChanges): void {
+    this.handleChanges(changes);
+  }
+}
+
 /**
  * @description
  * An interface implemented by classes that perform asynchronous validation.

packages/forms/src/forms.ts

@@ -43,7 +43,7 @@ export {FormGroupName} from './directives/reactive_directives/form_group_name';
 export {NgSelectOption, SelectControlValueAccessor} from './directives/select_control_value_accessor';
 export {SelectMultipleControlValueAccessor} from './directives/select_multiple_control_value_accessor';
 export {ɵNgSelectMultipleOption} from './directives/select_multiple_control_value_accessor';
-export {AsyncValidator, AsyncValidatorFn, CheckboxRequiredValidator, EmailValidator, MaxLengthValidator, MinLengthValidator, PatternValidator, RequiredValidator, ValidationErrors, Validator, ValidatorFn} from './directives/validators';
+export {AsyncValidator, AsyncValidatorFn, CheckboxRequiredValidator, EmailValidator, MaxLengthValidator, MaxValidator, MinLengthValidator, MinValidator, PatternValidator, RequiredValidator, ValidationErrors, Validator, ValidatorFn} from './directives/validators';
 export {FormBuilder} from './form_builder';
 export {AbstractControl, AbstractControlOptions, FormArray, FormControl, FormGroup} from './model';
 export {NG_ASYNC_VALIDATORS, NG_VALIDATORS, Validators} from './validators';

packages/forms/test/reactive_integration_spec.ts

@@ -10,7 +10,7 @@ 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, NG_ASYNC_VALIDATORS, NG_VALIDATORS, NG_VALUE_ACCESSOR, ReactiveFormsModule, Validator, Validators} from '@angular/forms';
+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';
@@ -2346,6 +2346,211 @@ const ValueAccessorB = createControlValueAccessor('[cva-b]');
            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', () => {
@@ -4461,3 +4666,31 @@ 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;
+}

packages/forms/test/template_integration_spec.ts

@@ -7,9 +7,9 @@
  */
 
 import {ɵgetDOM as getDOM} from '@angular/common';
-import {Component, Directive, forwardRef, Type} from '@angular/core';
+import {Component, Directive, forwardRef, Input, Type, ViewChild} from '@angular/core';
 import {ComponentFixture, fakeAsync, TestBed, tick, waitForAsync} from '@angular/core/testing';
-import {AbstractControl, AsyncValidator, COMPOSITION_BUFFER_MODE, FormControl, FormsModule, NG_ASYNC_VALIDATORS, NgForm, NgModel} from '@angular/forms';
+import {AbstractControl, AsyncValidator, COMPOSITION_BUFFER_MODE, ControlValueAccessor, FormControl, FormsModule, MaxValidator, MinValidator, NG_ASYNC_VALIDATORS, NG_VALIDATORS, NG_VALUE_ACCESSOR, NgForm, NgModel} 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} from 'rxjs';
@@ -1511,6 +1511,462 @@ import {NgModelCustomComp, NgModelCustomWrapper} from './value_accessor_integrat
            expect(onNgModelChange).toHaveBeenCalledTimes(2);
            tick();
          }));
+
+      it('should validate max', fakeAsync(() => {
+           const fixture = initTest(NgModelMaxValidator);
+           fixture.componentInstance.max = 10;
+           fixture.detectChanges();
+           tick();
+
+           const input = fixture.debugElement.query(By.css('input')).nativeElement;
+           const form = fixture.debugElement.children[0].injector.get(NgForm);
+
+           input.value = '';
+           dispatchEvent(input, 'input');
+           fixture.detectChanges();
+           expect(form.valid).toEqual(true);
+           expect(form.controls.max.errors).toBeNull();
+
+           input.value = 11;
+           dispatchEvent(input, 'input');
+           fixture.detectChanges();
+           expect(form.valid).toEqual(false);
+           expect(form.controls.max.errors).toEqual({max: {max: 10, actual: 11}});
+
+           input.value = 9;
+           dispatchEvent(input, 'input');
+           fixture.detectChanges();
+           expect(form.valid).toEqual(true);
+           expect(form.controls.max.errors).toBeNull();
+         }));
+
+      it('should apply max validation when control value is defined as a string', fakeAsync(() => {
+           const fixture = initTest(NgModelMaxValidator);
+           fixture.componentInstance.max = 10;
+           fixture.detectChanges();
+           tick();
+
+           const input = fixture.debugElement.query(By.css('input')).nativeElement;
+           const form = fixture.debugElement.children[0].injector.get(NgForm);
+
+           input.value = '11';
+           dispatchEvent(input, 'input');
+           fixture.detectChanges();
+           expect(form.valid).toEqual(false);
+           expect(form.controls.max.errors).toEqual({max: {max: 10, actual: 11}});
+
+           input.value = '9';
+           dispatchEvent(input, 'input');
+           fixture.detectChanges();
+           expect(form.valid).toEqual(true);
+           expect(form.controls.max.errors).toBeNull();
+         }));
+
+      it('should re-validate if max changes', fakeAsync(() => {
+           const fixture = initTest(NgModelMaxValidator);
+           fixture.componentInstance.max = 10;
+           fixture.detectChanges();
+           tick();
+
+           const input = fixture.debugElement.query(By.css('input')).nativeElement;
+           const form = fixture.debugElement.children[0].injector.get(NgForm);
+
+           input.value = 11;
+           dispatchEvent(input, 'input');
+           fixture.detectChanges();
+           expect(form.valid).toEqual(false);
+           expect(form.controls.max.errors).toEqual({max: {max: 10, actual: 11}});
+
+           input.value = 9;
+           dispatchEvent(input, 'input');
+           fixture.detectChanges();
+           expect(form.valid).toEqual(true);
+           expect(form.controls.max.errors).toBeNull();
+
+           fixture.componentInstance.max = 5;
+           fixture.detectChanges();
+           expect(form.valid).toEqual(false);
+           expect(form.controls.max.errors).toEqual({max: {max: 5, actual: 9}});
+         }));
+
+      it('should validate min', fakeAsync(() => {
+           const fixture = initTest(NgModelMinValidator);
+           fixture.componentInstance.min = 10;
+           fixture.detectChanges();
+           tick();
+
+           const input = fixture.debugElement.query(By.css('input')).nativeElement;
+           const form = fixture.debugElement.children[0].injector.get(NgForm);
+
+           input.value = '';
+           dispatchEvent(input, 'input');
+           fixture.detectChanges();
+           expect(form.valid).toEqual(true);
+           expect(form.controls.min.errors).toBeNull();
+
+           input.value = 11;
+           dispatchEvent(input, 'input');
+           fixture.detectChanges();
+           expect(form.valid).toEqual(true);
+           expect(form.controls.min.errors).toBeNull();
+
+           input.value = 9;
+           dispatchEvent(input, 'input');
+           fixture.detectChanges();
+           expect(form.valid).toEqual(false);
+           expect(form.controls.min.errors).toEqual({min: {min: 10, actual: 9}});
+         }));
+
+      it('should apply min validation when control value is defined as a string', fakeAsync(() => {
+           const fixture = initTest(NgModelMinValidator);
+           fixture.componentInstance.min = 10;
+           fixture.detectChanges();
+           tick();
+
+           const input = fixture.debugElement.query(By.css('input')).nativeElement;
+           const form = fixture.debugElement.children[0].injector.get(NgForm);
+
+           input.value = '11';
+           dispatchEvent(input, 'input');
+           fixture.detectChanges();
+           expect(form.valid).toEqual(true);
+           expect(form.controls.min.errors).toBeNull();
+
+           input.value = '9';
+           dispatchEvent(input, 'input');
+           fixture.detectChanges();
+           expect(form.valid).toEqual(false);
+           expect(form.controls.min.errors).toEqual({min: {min: 10, actual: 9}});
+         }));
+
+      it('should re-validate if min changes', fakeAsync(() => {
+           const fixture = initTest(NgModelMinValidator);
+           fixture.componentInstance.min = 10;
+           fixture.detectChanges();
+           tick();
+
+           const input = fixture.debugElement.query(By.css('input')).nativeElement;
+           const form = fixture.debugElement.children[0].injector.get(NgForm);
+
+           input.value = 11;
+           dispatchEvent(input, 'input');
+           fixture.detectChanges();
+           expect(form.valid).toEqual(true);
+           expect(form.controls.min.errors).toBeNull();
+
+           input.value = 9;
+           dispatchEvent(input, 'input');
+           fixture.detectChanges();
+           expect(form.valid).toEqual(false);
+           expect(form.controls.min.errors).toEqual({min: {min: 10, actual: 9}});
+
+           fixture.componentInstance.min = 9;
+           fixture.detectChanges();
+           expect(form.valid).toEqual(true);
+           expect(form.controls.min.errors).toBeNull();
+         }));
+
+      it('should not include the min and max validators when using another directive with the same properties',
+         fakeAsync(() => {
+           const fixture = initTest(NgModelNoMinMaxValidator);
+           const validateFnSpy = spyOn(MaxValidator.prototype, 'validate');
+
+           fixture.componentInstance.min = 10;
+           fixture.componentInstance.max = 20;
+           fixture.detectChanges();
+           tick();
+
+           const min = fixture.debugElement.query(By.directive(MinValidator));
+           expect(min).toBeNull();
+
+           const max = fixture.debugElement.query(By.directive(MaxValidator));
+           expect(max).toBeNull();
+
+           const cd = fixture.debugElement.query(By.directive(CustomDirective));
+           expect(cd).toBeDefined();
+
+           expect(validateFnSpy).not.toHaveBeenCalled();
+         }));
+
+      it('should not include the min and max validators when using a custom component with the same properties',
+         fakeAsync(() => {
+           @Directive({
+             selector: 'my-custom-component',
+             providers: [{
+               provide: NG_VALUE_ACCESSOR,
+               multi: true,
+               useExisting: forwardRef(() => MyCustomComponentDirective),
+             }]
+           })
+           class MyCustomComponentDirective implements ControlValueAccessor {
+             @Input() min!: number;
+             @Input() max!: number;
+
+             writeValue(obj: any): void {}
+             registerOnChange(fn: any): void {}
+             registerOnTouched(fn: any): void {}
+           }
+
+           @Component({
+             template: `
+              <!-- no min/max validators should be matched on these elements -->
+              <my-custom-component name="min" ngModel [min]="min"></my-custom-component>
+              <my-custom-component name="max" ngModel [max]="max"></my-custom-component>
+            `
+           })
+           class AppComponent {
+           }
+
+           const fixture = initTest(AppComponent, MyCustomComponentDirective);
+           const validateFnSpy = spyOn(MaxValidator.prototype, 'validate');
+
+           fixture.detectChanges();
+           tick();
+
+           const mv = fixture.debugElement.query(By.directive(MaxValidator));
+           expect(mv).toBeNull();
+
+           const cd = fixture.debugElement.query(By.directive(CustomDirective));
+           expect(cd).toBeDefined();
+
+           expect(validateFnSpy).not.toHaveBeenCalled();
+         }));
+
+      it('should not include the min and max validators for inputs with type range',
+         fakeAsync(() => {
+           @Component({template: '<input type="range" min="10" max="20">'})
+           class AppComponent {
+           }
+
+           const fixture = initTest(AppComponent);
+           const maxValidateFnSpy = spyOn(MaxValidator.prototype, 'validate');
+           const minValidateFnSpy = spyOn(MinValidator.prototype, 'validate');
+
+           fixture.detectChanges();
+           tick();
+
+           const maxValidator = fixture.debugElement.query(By.directive(MaxValidator));
+           expect(maxValidator).toBeNull();
+
+           const minValidator = fixture.debugElement.query(By.directive(MinValidator));
+           expect(minValidator).toBeNull();
+
+           expect(maxValidateFnSpy).not.toHaveBeenCalled();
+           expect(minValidateFnSpy).not.toHaveBeenCalled();
+         }));
+
+      ['number', 'string'].forEach((inputType: string) => {
+        it(`should validate min and max when constraints are represented using a ${inputType}`,
+           fakeAsync(() => {
+             const fixture = initTest(NgModelMinMaxValidator);
+
+             fixture.componentInstance.min = inputType === 'string' ? '5' : 5;
+             fixture.componentInstance.max = inputType === 'string' ? '10' : 10;
+
+             fixture.detectChanges();
+             tick();
+
+             const input = fixture.debugElement.query(By.css('input')).nativeElement;
+             const form = fixture.debugElement.children[0].injector.get(NgForm);
+
+             input.value = '';
+             dispatchEvent(input, 'input');
+             fixture.detectChanges();
+             expect(form.valid).toEqual(true);
+             expect(form.controls.min_max.errors).toBeNull();
+
+             input.value = 11;
+             dispatchEvent(input, 'input');
+             fixture.detectChanges();
+             expect(form.valid).toEqual(false);
+             expect(form.controls.min_max.errors).toEqual({max: {max: 10, actual: 11}});
+
+             input.value = 4;
+             dispatchEvent(input, 'input');
+             fixture.detectChanges();
+             expect(form.valid).toEqual(false);
+             expect(form.controls.min_max.errors).toEqual({min: {min: 5, actual: 4}});
+
+             input.value = 9;
+             dispatchEvent(input, 'input');
+             fixture.detectChanges();
+             expect(form.valid).toEqual(true);
+             expect(form.controls.min_max.errors).toBeNull();
+           }));
+      });
+      it('should validate min and max', fakeAsync(() => {
+           const fixture = initTest(NgModelMinMaxValidator);
+           fixture.componentInstance.min = 5;
+           fixture.componentInstance.max = 10;
+           fixture.detectChanges();
+           tick();
+
+           const input = fixture.debugElement.query(By.css('input')).nativeElement;
+           const form = fixture.debugElement.children[0].injector.get(NgForm);
+
+           input.value = '';
+           dispatchEvent(input, 'input');
+           fixture.detectChanges();
+           expect(form.valid).toEqual(true);
+           expect(form.controls.min_max.errors).toBeNull();
+
+           input.value = 11;
+           dispatchEvent(input, 'input');
+           fixture.detectChanges();
+           expect(form.valid).toEqual(false);
+           expect(form.controls.min_max.errors).toEqual({max: {max: 10, actual: 11}});
+
+           input.value = 4;
+           dispatchEvent(input, 'input');
+           fixture.detectChanges();
+           expect(form.valid).toEqual(false);
+           expect(form.controls.min_max.errors).toEqual({min: {min: 5, actual: 4}});
+
+           input.value = 9;
+           dispatchEvent(input, 'input');
+           fixture.detectChanges();
+           expect(form.valid).toEqual(true);
+           expect(form.controls.min_max.errors).toBeNull();
+         }));
+
+      it('should apply min and max validation when control value is defined as a string',
+         fakeAsync(() => {
+           const fixture = initTest(NgModelMinMaxValidator);
+           fixture.componentInstance.min = 5;
+           fixture.componentInstance.max = 10;
+           fixture.detectChanges();
+           tick();
+
+           const input = fixture.debugElement.query(By.css('input')).nativeElement;
+           const form = fixture.debugElement.children[0].injector.get(NgForm);
+
+           input.value = '';
+           dispatchEvent(input, 'input');
+           fixture.detectChanges();
+           expect(form.valid).toEqual(true);
+           expect(form.controls.min_max.errors).toBeNull();
+
+           input.value = '11';
+           dispatchEvent(input, 'input');
+           fixture.detectChanges();
+           expect(form.valid).toEqual(false);
+           expect(form.controls.min_max.errors).toEqual({max: {max: 10, actual: 11}});
+
+           input.value = '4';
+           dispatchEvent(input, 'input');
+           fixture.detectChanges();
+           expect(form.valid).toEqual(false);
+           expect(form.controls.min_max.errors).toEqual({min: {min: 5, actual: 4}});
+
+           input.value = '9';
+           dispatchEvent(input, 'input');
+           fixture.detectChanges();
+           expect(form.valid).toEqual(true);
+           expect(form.controls.min_max.errors).toBeNull();
+         }));
+
+      it('should re-validate if min/max changes', fakeAsync(() => {
+           const fixture = initTest(NgModelMinMaxValidator);
+           fixture.componentInstance.min = 5;
+           fixture.componentInstance.max = 10;
+           fixture.detectChanges();
+           tick();
+
+           const input = fixture.debugElement.query(By.css('input')).nativeElement;
+           const form = fixture.debugElement.children[0].injector.get(NgForm);
+
+           input.value = 10;
+           dispatchEvent(input, 'input');
+           fixture.detectChanges();
+           expect(form.valid).toEqual(true);
+           expect(form.controls.min_max.errors).toBeNull();
+
+           input.value = 12;
+           dispatchEvent(input, 'input');
+           fixture.detectChanges();
+           expect(form.valid).toEqual(false);
+           expect(form.controls.min_max.errors).toEqual({max: {max: 10, actual: 12}});
+
+           fixture.componentInstance.max = 12;
+           fixture.detectChanges();
+           expect(form.valid).toEqual(true);
+           expect(form.controls.min_max.errors).toBeNull();
+
+           input.value = 5;
+           dispatchEvent(input, 'input');
+           fixture.detectChanges();
+           expect(form.valid).toEqual(true);
+           expect(form.controls.min_max.errors).toBeNull();
+
+           input.value = 0;
+           dispatchEvent(input, 'input');
+           fixture.detectChanges();
+           expect(form.valid).toEqual(false);
+           expect(form.controls.min_max.errors).toEqual({min: {min: 5, actual: 0}});
+
+           fixture.componentInstance.min = 0;
+           fixture.detectChanges();
+           expect(form.valid).toEqual(true);
+           expect(form.controls.min_max.errors).toBeNull();
+         }));
+
+      it('should run min/max validation for empty values ', fakeAsync(() => {
+           const fixture = initTest(NgModelMinMaxValidator);
+           fixture.componentInstance.min = 5;
+           fixture.componentInstance.max = 10;
+           fixture.detectChanges();
+           tick();
+
+           const input = fixture.debugElement.query(By.css('input')).nativeElement;
+           const form = fixture.debugElement.children[0].injector.get(NgForm);
+
+           const maxValidateFnSpy = spyOn(MaxValidator.prototype, 'validate');
+           const minValidateFnSpy = spyOn(MinValidator.prototype, 'validate');
+
+           input.value = '';
+           dispatchEvent(input, 'input');
+           fixture.detectChanges();
+           expect(form.valid).toEqual(true);
+           expect(form.controls.min_max.errors).toBeNull();
+
+           expect(maxValidateFnSpy).toHaveBeenCalled();
+           expect(minValidateFnSpy).toHaveBeenCalled();
+         }));
+
+      it('should run min/max validation for negative values', fakeAsync(() => {
+           const fixture = initTest(NgModelMinMaxValidator);
+           fixture.componentInstance.min = -20;
+           fixture.componentInstance.max = -10;
+           fixture.detectChanges();
+           tick();
+
+           const input = fixture.debugElement.query(By.css('input')).nativeElement;
+           const form = fixture.debugElement.children[0].injector.get(NgForm);
+
+           input.value = '-30';
+           dispatchEvent(input, 'input');
+           fixture.detectChanges();
+           expect(form.valid).toBeFalse();
+           expect(form.controls.min_max.errors).toEqual({min: {min: -20, actual: -30}});
+
+           input.value = -15;
+           dispatchEvent(input, 'input');
+           fixture.detectChanges();
+           expect(form.valid).toBeTruthy();
+           expect(form.controls.min_max.errors).toBeNull();
+
+           input.value = -5;
+           dispatchEvent(input, 'input');
+           fixture.detectChanges();
+           expect(form.valid).toBeFalse();
+           expect(form.controls.min_max.errors).toEqual({max: {max: -10, actual: -5}});
+
+           input.value = 0;
+           dispatchEvent(input, 'input');
+           fixture.detectChanges();
+           expect(form.valid).toBeFalse();
+           expect(form.controls.min_max.errors).toEqual({max: {max: -10, actual: 0}});
+         }));
     });
 
     describe('IME events', () => {
@@ -1879,3 +2335,50 @@ class NgModelChangesForm {
 class NgModelChangeState {
   onNgModelChange = () => {};
 }
+
+@Component({
+  selector: 'ng-model-max',
+  template: `<form><input name="max" type="number" ngModel [max]="max"></form>`
+})
+class NgModelMaxValidator {
+  max!: number;
+}
+
+@Component({
+  selector: 'ng-model-min',
+  template: `<form><input name="min" type="number" ngModel [min]="min"></form>`
+})
+class NgModelMinValidator {
+  min!: number;
+}
+
+@Component({
+  selector: 'ng-model-min-max',
+  template: `
+    <form><input name="min_max" type="number" ngModel [min]="min" [max]="max"></form>`
+})
+class NgModelMinMaxValidator {
+  min!: number|string;
+  max!: number|string;
+}
+
+@Directive({selector: '[myDir]'})
+class CustomDirective {
+  @Input() min!: number;
+  @Input() max!: number;
+}
+
+@Component({
+  selector: 'ng-model-no-min-max',
+  template: `
+    <form>
+      <input name="min" type="text" ngModel [min]="min" myDir>
+      <input name="max" type="text" ngModel [max]="max" myDir>
+    </form>
+  `,
+})
+class NgModelNoMinMaxValidator {
+  min!: number;
+  max!: number;
+  @ViewChild('myDir') myDir: any;
+}