Add synthetic Rijksregisternummer / INSZ generator

README.md

@@ -9,7 +9,7 @@ This package contains the reusable local processing logic behind parts of [grati
 - Belgian enterprise and VAT number validation
 - Belgian IBAN, bank code and BIC helpers
 - OGM and RF payment reference helpers
-- Belgian national number parsing
+- Belgian national number parsing and synthetic RN/BIS/INSZ test-number generation
 - Peppol participant ID parsing
 - CODA parsing and anonymisation
 - CAMT parsing
@@ -119,11 +119,12 @@ npm test
 ## Example
 
 ```js
-import { parseEnterprise, parseIban, parseOgm } from './src/index.js';
+import { parseEnterprise, parseIban, parseOgm, makeInsz } from './src/index.js';
 
 console.log(parseEnterprise('BE 0753.124.628'));
 console.log(parseIban('BE73 7350 1234 5660'));
 console.log(parseOgm('+++202/6000/12320+++'));
+console.log(makeInsz({ type: 'national', birthDate: '2099-01-01', sex: 'female', sequence: 2 }));
 ```
 
 ## Scope

src/be/ids.js

@@ -235,6 +235,68 @@ export function parseNationalNumber(input) {
   return out;
 }
 
+
+function parseSyntheticBirthDate(value) {
+  const m = /^(\d{4})-(\d{2})-(\d{2})$/.exec(String(value || ''));
+  if (!m) throw new Error('Use a birth date as YYYY-MM-DD.');
+  const year = +m[1], month = +m[2], day = +m[3];
+  if (year < 1900 || year > 2099) throw new Error('Synthetic INSZ generation supports years 1900-2099.');
+  const d = new Date(Date.UTC(year, month - 1, day));
+  if (d.getUTCFullYear() !== year || d.getUTCMonth() !== month - 1 || d.getUTCDate() !== day) throw new Error('Birth date is not a valid calendar date.');
+  return { year, month, day };
+}
+
+function syntheticSequence(sequence, odd) {
+  const n = Number(sequence);
+  if (!Number.isInteger(n) || n < 1 || n > 998) throw new Error('Sequence must be an integer from 001 to 998.');
+  if ((n % 2 === 1) !== odd) throw new Error(odd ? 'Sequence must be odd.' : 'Sequence must be even.');
+  return String(n).padStart(3, '0');
+}
+
+function inszFromBase(base, year) {
+  const source = year >= 2000 ? `2${base}` : base;
+  const check = String(97 - mod97(source)).padStart(2, '0');
+  return base + check;
+}
+
+/**
+ * Create a structurally valid synthetic Belgian national register number.
+ * This does not reserve the number and cannot prove that it is unassigned.
+ */
+export function makeNationalNumber({ birthDate, sex = 'male', sequence } = {}) {
+  const { year, month, day } = parseSyntheticBirthDate(birthDate);
+  if (!['male', 'female'].includes(sex)) throw new Error('Sex must be "male" or "female".');
+  const odd = sex === 'male';
+  const seq = syntheticSequence(sequence ?? (odd ? 1 : 2), odd);
+  const base = `${String(year).slice(-2)}${String(month).padStart(2, '0')}${String(day).padStart(2, '0')}${seq}`;
+  const digits = inszFromBase(base, year);
+  return { ...parseNationalNumber(digits), digits, synthetic: true, kind: 'national' };
+}
+
+/**
+ * Create a structurally valid synthetic BIS number.
+ * For BIS numbers the month is offset by 40 when sex was known at creation,
+ * or by 20 when it was unknown. Unknown-sex BIS sequence numbers are odd.
+ */
+export function makeBisNumber({ birthDate, sex = 'male', sexKnown = true, sequence } = {}) {
+  const { year, month, day } = parseSyntheticBirthDate(birthDate);
+  if (!['male', 'female'].includes(sex)) throw new Error('Sex must be "male" or "female".');
+  const odd = sexKnown ? sex === 'male' : true;
+  const seq = syntheticSequence(sequence ?? (odd ? 1 : 2), odd);
+  const encodedMonth = month + (sexKnown ? 40 : 20);
+  const base = `${String(year).slice(-2)}${String(encodedMonth).padStart(2, '0')}${String(day).padStart(2, '0')}${seq}`;
+  const digits = inszFromBase(base, year);
+  return { ...parseNationalNumber(digits), digits, synthetic: true, kind: 'bis', sexKnown };
+}
+
+/** Convenience wrapper for synthetic INSZ test data. */
+export function makeInsz({ type = 'national', ...options } = {}) {
+  if (type === 'national') return makeNationalNumber(options);
+  if (type === 'bis') return makeBisNumber({ ...options, sexKnown: options.sexKnown !== false });
+  if (type === 'bis-unknown') return makeBisNumber({ ...options, sexKnown: false });
+  throw new Error('Type must be "national", "bis" or "bis-unknown".');
+}
+
 // ---------- Peppol participant IDs ----------
 
 export const PEPPOL_SCHEMES = {

test/core.test.js

@@ -2,7 +2,7 @@ import { test } from 'node:test';
 import assert from 'node:assert/strict';
 
 import {
-  parseEnterprise, parseIban, parseOgm, parsePeppolId,
+  parseEnterprise, parseIban, parseOgm, parsePeppolId, parseNationalNumber, makeNationalNumber, makeBisNumber, makeInsz,
   parseCoda, parseCamt, readUbl, validateInvoice,
   parseIntervat, parseXbrl, epcPayload,
   wgs84ToLambert72, lambert72ToWgs84,
@@ -23,6 +23,23 @@ test('Belgian identifiers', () => {
   assert.equal(parsePeppolId('0208:0753124628').valid, true);
 });
 
+
+test('synthetic Belgian INSZ generators', () => {
+  const rrn = makeNationalNumber({ birthDate: '1985-07-30', sex: 'male', sequence: 33 });
+  assert.equal(rrn.formatted, '85.07.30-033.28');
+  assert.equal(parseNationalNumber(rrn.digits).valid, true);
+  const modern = makeNationalNumber({ birthDate: '2005-01-01', sex: 'female', sequence: 124 });
+  assert.equal(modern.birthDate, '2005-01-01');
+  assert.equal(modern.sex, 'female');
+  const bis = makeBisNumber({ birthDate: '1990-03-15', sex: 'female', sexKnown: true, sequence: 2 });
+  assert.equal(bis.valid, true);
+  assert.equal(bis.type, 'BIS number (sex known)');
+  const unknown = makeInsz({ type: 'bis-unknown', birthDate: '2099-01-01', sequence: 1 });
+  assert.equal(unknown.valid, true);
+  assert.equal(unknown.type, 'BIS number (sex unknown at registration)');
+  assert.throws(() => makeNationalNumber({ birthDate: '2005-01-01', sex: 'female', sequence: 123 }), /even/);
+});
+
 test('CODA and CAMT', () => {
   const [coda] = parseCoda(codaSample);
   assert.ok(coda.transactions.length > 0);