Min-max validator

min-max.ts

import { AbstractControl } from '@angular/forms';
import { ValidatorFn } from '@angular/forms';

export function minMax(min: number, max: number): ValidatorFn {
  return (control: AbstractControl): { [key: string]: any } => {
    return control.value < min || control.value > max ?
      { 'invalidNumber': true } :
      <any>null;
  };
}