feat: add credit card validator

npm/ng-packs/packages/core/src/lib/tests/validators.spec.ts

@@ -1,7 +1,46 @@
 import { FormControl } from '@angular/forms';
+import { validateCreditCard } from '../validators/credit-card.validator';
 import { validateRequired } from '../validators/required.validator';
 
 describe('Validators', () => {
+  describe('Credit Card Validator', () => {
+    const error = { creditCardNumber: true };
+
+    test.each`
+      input                                       | expected
+      ${'0'}                                      | ${error}
+      ${'5105105105105100' /* Mastercard */}      | ${null}
+      ${'5105105105105101' /* Mastercard */}      | ${error}
+      ${'5105 1051 0510 5100'}                    | ${null}
+      ${'5105-1051-0510-5100'}                    | ${null}
+      ${'5105 - 1051 - 0510 - 5100'}              | ${null}
+      ${'4111111111111111' /*Visa*/}              | ${null}
+      ${'4111111111111112' /*Visa*/}              | ${error}
+      ${'4012888888881881' /* Visa */}            | ${null}
+      ${'4012888888881882' /* Visa */}            | ${error}
+      ${'4222222222222' /* Visa */}               | ${null}
+      ${'4222222222223' /* Visa */}               | ${error}
+      ${'378282246310005' /* American Express */} | ${null}
+      ${'378282246310006' /* American Express */} | ${error}
+      ${'6011111111111117' /* Discover */}        | ${null}
+      ${'6011111111111118' /* Discover */}        | ${error}
+    `('should return $expected when input is $input', ({ input, expected }) => {
+      const control = new FormControl(input, [validateCreditCard()]);
+      control.markAsDirty({ onlySelf: true });
+      control.updateValueAndValidity({ onlySelf: true, emitEvent: false });
+
+      expect(control.errors).toEqual(expected);
+    });
+
+    it('should return null when control is pristine', () => {
+      const invalidNumber = '5105105105105101';
+      const control = new FormControl(invalidNumber, [validateCreditCard()]);
+      // control is not dirty
+
+      expect(control.valid).toBe(true);
+    });
+  });
+
   describe('Required Validator', () => {
     const error = { required: true };
 

npm/ng-packs/packages/core/src/lib/validators/credit-card.validator.ts

@@ -0,0 +1,32 @@
+import { AbstractControl, ValidatorFn } from '@angular/forms';
+
+export interface CreditCardError {
+  creditCardNumber: true;
+}
+
+export function validateCreditCard(): ValidatorFn {
+  return (control: AbstractControl): CreditCardError | null => {
+    if (control.pristine) return null;
+
+    return isValidCreditCard(String(control.value)) ? null : { creditCardNumber: true };
+  };
+}
+
+function isValidCreditCard(value: string): boolean {
+  value = value.replace(/[ -]/g, '');
+
+  if (!/^[0-9]{13,19}$/.test(value)) return false;
+
+  let checksum = 0;
+  let multiplier = 1;
+
+  for (let i = value.length; i > 0; i--) {
+    const digit = Number(value[i - 1]) * multiplier;
+    /* tslint:disable-next-line:no-bitwise */
+    checksum += (digit % 10) + ~~(digit / 10);
+
+    multiplier = (multiplier * 2) % 3;
+  }
+
+  return checksum % 10 === 0;
+}

npm/ng-packs/packages/core/src/lib/validators/index.ts

@@ -1,8 +1,11 @@
 import { Validators } from '@angular/forms';
+import { validateCreditCard } from './credit-card.validator';
 import { validateRequired } from './required.validator';
+export * from './credit-card.validator';
 export * from './required.validator';
 
 export const AbpValidators = {
+  creditCard: validateCreditCard,
   email: () => Validators.email,
   required: validateRequired,
 };