more tests

Author: alexanbj

packages/validation/src/no.ts

@@ -109,11 +109,14 @@ type PersonalIdentityNumberOptions = ValidatorOptions;
 /**
  * Validates that the input value is a Norwegian national identity number.
  *
- * Supports both fødselsnummer and d-number.
+ * Supports both fødselsnummer and d-nummer.
  * @example
  * ```
+ * // Fødselsnummer
  * validatePersonalIdentityNumber('21075417753') // => true
- * validatePersonalIdentityNumber('61075440676') // => true
+ *
+ * // D-nummer
+ * validatePersonalIdentityNumber('53097248016') // => true
  * ```
  */
 export function validateNationalIdentityNumber(
@@ -125,9 +128,9 @@ export function validateNationalIdentityNumber(
     value = stripFormatting(value);
   }
 
-  // Fødselsn
-  // Fødselsnummer and d numbers have two control digits.
-  // where the first one is calculated using the first 10 digits.
+  // Norwegian national identity numbers use mod 11 with two control digits.
+  // The first one is calculated for the first 10d digits
+  // while the last one uses all 11 digits
   const valueForControlDigit1 = value.slice(0, -1);
   const controlDigit1 = mod11(
     valueForControlDigit1,
@@ -141,14 +144,20 @@ export function validateNationalIdentityNumber(
 
   let day = Number(value.substring(0, 2));
   const month = Number(value.substring(2, 4));
-  const year = Number(value.substring(4, 6));
+  let year = Number(value.substring(4, 6));
+
+  // 1900 isn't a leap year
+  if (year === 0) {
+    year = 2000;
+  }
 
   // for a d-number the first digit is increased by 4. Eg the 31st of a month would be 71, or the 3rd would be 43.
   // thus we need to subtract 40 to get the correct day of the month
   if (day >= 40) {
     day = day - 40;
   }
 
+  // important to use UTC so the user's timezone doesn't affect the validation
   const date = new Date(Date.UTC(year, month - 1, day));
 
   return date && date.getUTCMonth() === month - 1 && date.getUTCDate() === day;

packages/validation/src/validation.test.ts

@@ -60,20 +60,53 @@ describe('no', () => {
     expect(no.validateObosMembershipNumber(input, options)).toBe(expected);
   });
 
-  test('validateNationalIdentityNumber()', () => {
+  test('validateNationalIdentityNumber() - validates fødselsnummer', () => {
     for (let i = 0; i < 1000; ++i) {
-      expect(
-        no.validateNationalIdentityNumber(
-          navfaker.personIdentifikator.fødselsnummer(),
-        ),
-      ).toBe(true);
-      expect(
-        no.validateNationalIdentityNumber(
-          navfaker.personIdentifikator.dnummer(),
-        ),
-      ).toBe(true);
+      const fnr = navfaker.personIdentifikator.fødselsnummer();
+      expect(no.validateNationalIdentityNumber(fnr), `${fnr} is valid`).toBe(
+        true,
+      );
     }
   });
+
+  test('validateNationalIdentityNumber() - validates d-nummer', () => {
+    for (let i = 0; i < 1000; ++i) {
+      const dnr = navfaker.personIdentifikator.dnummer();
+      expect(no.validateNationalIdentityNumber(dnr), `${dnr} is valid`).toBe(
+        true,
+      );
+    }
+  });
+
+  test('validateNationalIdentityNumber() - validates leap years', () => {
+    expect(no.validateNationalIdentityNumber('29029648784')).toBe(true);
+  });
+
+  test('validateNationalIdentityNumber() - validates 00 as a leap year', () => {
+    expect(no.validateNationalIdentityNumber('29020075838')).toBe(true);
+  });
+
+  test('validateNationalIdentityNumber() - returns false for invalid identity numbers', () => {
+    expect(
+      no.validateNationalIdentityNumber('13097248032'),
+      '1st control digit is invalid',
+    ).toBe(false);
+
+    expect(
+      no.validateNationalIdentityNumber('13097248023'),
+      '2nd control digit is invalid',
+    ).toBe(false);
+
+    expect(
+      no.validateNationalIdentityNumber('32127248022'),
+      'day is invalid',
+    ).toBe(false);
+
+    expect(
+      no.validateNationalIdentityNumber('13137248022'),
+      'month is invalid',
+    ).toBe(false);
+  });
 });
 
 describe('se', () => {