feat: norwegian account, organization and national identification number validation

* add mod 11 function

* add isValidAccountNumber

* add organization number validator

* make mod11 more generic

* add checksum validation to birth number

* linting

* formatting

* move mod11 to utils module

* prettier

* Specify nationality on account, organization and national identification numbers

Author: thrap

src/utils/mod11.test.ts

@@ -0,0 +1,18 @@
+import each from 'jest-each';
+
+import { mod11 } from './mod11';
+
+describe('utils', () => {
+  describe('mod11', () => {
+    each`
+      value           | expected
+      ${'1234567890'} | ${3}
+      ${'234567'}     | ${6}
+    `.it(
+      'should return $expected when validating $value',
+      ({ value, expected }) => {
+        expect(mod11(value)).toBe(expected);
+      }
+    );
+  });
+});

src/utils/mod11.ts

@@ -0,0 +1,14 @@
+// https://no.wikipedia.org/wiki/MOD11
+export const mod11 = (
+  value: string,
+  factors: number[] = [2, 3, 4, 5, 6, 7]
+): number => {
+  const sum = value
+    .split('')
+    .reverse()
+    .reduce(
+      (acc, x, i) => acc + parseInt(x, 10) * factors[i % factors.length],
+      0
+    );
+  return (11 - (sum % 11)) % 11;
+};

src/validators/account-number/account-number-validator.test.ts

@@ -0,0 +1,23 @@
+import each from 'jest-each';
+
+import { isValidNorwegianAccountNumber } from './account-number-validator';
+
+describe('account-number-validator', () => {
+  describe('isValidNorwegianAccountNumber', () => {
+    each`
+      accountNumber         | expected
+      ${1}                  | ${false}
+      ${undefined}          | ${false}
+      ${null}               | ${false}
+      ${'1234567890'}       | ${false}
+      ${'12345678903'}      | ${true}
+      ${'1234.56.78903'}    | ${true}
+      ${12345678903}        | ${true}
+    `.it(
+      'should return $expected when validating $accountNumber',
+      ({ accountNumber, expected }) => {
+        expect(isValidNorwegianAccountNumber(accountNumber)).toBe(expected);
+      }
+    );
+  });
+});

src/validators/account-number/account-number-validator.ts

@@ -0,0 +1,11 @@
+import { mod11 } from '../../utils/mod11';
+
+export const isValidNorwegianAccountNumber = (
+  accountNumber: string
+): boolean => {
+  const trimmed = ('' + accountNumber).replace(/\./g, '').trim();
+  return (
+    /^\d{11}$/.test(trimmed) &&
+    mod11(trimmed.substr(0, 10)) === parseInt(trimmed.substr(-1), 10)
+  );
+};

src/validators/national-identification-number/national-identification-number.test.ts

@@ -0,0 +1,26 @@
+import each from 'jest-each';
+
+import { isValidNorwegianIdentificationNumber } from './national-identification-number';
+
+describe('national-identification-number', () => {
+  describe('isValidNorwegianIdentificationNumber', () => {
+    each`
+      birthNumber         | expected
+      ${1}                | ${false}
+      ${undefined}        | ${false}
+      ${null}             | ${false}
+      ${'01010123476'}    | ${true}
+      ${'01015780000'}    | ${false}
+      ${'29029633310'}    | ${true}
+      ${'47086303651'}    | ${true}
+      ${47086303651}      | ${true}
+    `.it(
+      'should return $expected when validating $birthNumber',
+      ({ birthNumber, expected }) => {
+        expect(isValidNorwegianIdentificationNumber(birthNumber)).toBe(
+          expected
+        );
+      }
+    );
+  });
+});

src/validators/national-identification-number/national-identification-number.ts

@@ -0,0 +1,19 @@
+import { mod11 } from '../../utils/mod11';
+
+export const isValidNorwegianIdentificationNumber = (
+  birthNumber: string
+): boolean => {
+  const trimmed = ('' + birthNumber).replace(/ /g, '').trim();
+
+  if (!/^\d{11}$/.test(trimmed)) {
+    return false;
+  }
+
+  const checksum1 = mod11(trimmed.substr(0, 9), [2, 5, 4, 9, 8, 1, 6, 7, 3]);
+  const checksum2 = mod11(trimmed.substr(0, 10));
+
+  return (
+    checksum1 === parseInt(trimmed[9], 10) &&
+    checksum2 === parseInt(trimmed[10], 10)
+  );
+};

src/validators/organization-number/organization-number-validator.test.ts

@@ -0,0 +1,24 @@
+import each from 'jest-each';
+
+import { isValidNorwegianOrganizationNumber } from './organization-number-validator';
+
+describe('organization-number-validator', () => {
+  describe('isValidNorwegianOrganizationNumber', () => {
+    each`
+      organizationNumber   | expected
+      ${1}                 | ${false}
+      ${undefined}         | ${false}
+      ${null}              | ${false}
+      ${'12345678'}        | ${false}
+      ${'123456785'}       | ${true}
+      ${123456785}         | ${true}
+    `.it(
+      'should return $expected when validating $organizationNumber',
+      ({ organizationNumber, expected }) => {
+        expect(isValidNorwegianOrganizationNumber(organizationNumber)).toBe(
+          expected
+        );
+      }
+    );
+  });
+});

src/validators/organization-number/organization-number-validator.ts

@@ -0,0 +1,12 @@
+import { mod11 } from '../../utils/mod11';
+
+// https://www.brreg.no/om-oss/oppgavene-vare/alle-registrene-vare/om-enhetsregisteret/organisasjonsnummeret/
+export const isValidNorwegianOrganizationNumber = (
+  OrganizationNumber: string
+): boolean => {
+  const trimmed = ('' + OrganizationNumber).replace(/\./g, '').trim();
+  return (
+    /^\d{9}$/.test(trimmed) &&
+    mod11(trimmed.substr(0, 8)) === parseInt(trimmed.substr(-1), 10)
+  );
+};