BillTracker/tests/paymentAccountingService.test.js

'use strict';

// X2 — the payment-accounting source-of-truth layer (manual vs. bank) had no
// dedicated tests. Covers the bank-backed predicate, the accounting-active SQL
// fragment, and the core money-integrity invariant: when a bank payment lands it
// overrides a provisional manual payment (so it isn't double-counted) and the
// manual one counts again — with the balance restored/re-applied — if the bank
// override is later removed.
const test = require('node:test');
const assert = require('node:assert/strict');
const os = require('node:os');
const path = require('node:path');
const fs = require('node:fs');

const dbPath = path.join(os.tmpdir(), `bill-tracker-payacct-${process.pid}.sqlite`);
process.env.DB_PATH = dbPath;

const { getDb, closeDb } = require('../db/database');
const {
  isBankBackedPayment,
  accountingActiveSql,
  markProvisionalManualPaymentsOverridden,
  reactivatePaymentsOverriddenBy,
} = require('../services/paymentAccountingService');

test('isBankBackedPayment: bank sources or a transaction_id count as bank-backed', () => {
  assert.equal(isBankBackedPayment({ payment_source: 'provider_sync' }), true);
  assert.equal(isBankBackedPayment({ payment_source: 'transaction_match' }), true);
  assert.equal(isBankBackedPayment({ payment_source: 'auto_match' }), true);
  assert.equal(isBankBackedPayment({ payment_source: 'manual', transaction_id: 42 }), true);
  assert.equal(isBankBackedPayment({ payment_source: 'manual' }), false);
  assert.equal(isBankBackedPayment({}), false);
});

test('accountingActiveSql fragment, with and without a table alias', () => {
  assert.equal(accountingActiveSql(), 'COALESCE(accounting_excluded, 0) = 0');
  assert.equal(accountingActiveSql('p'), 'COALESCE(p.accounting_excluded, 0) = 0');
});

test('bank payment overrides a provisional manual payment, then reactivates on removal', () => {
  const db = getDb();
  const userId = db.prepare("INSERT INTO users (username, password_hash, role, active) VALUES ('pa-user','x','user',1)").run().lastInsertRowid;
  // $500 balance; a manual $100 payment already dropped it to $400.
  const billId = db.prepare(
    "INSERT INTO bills (user_id, name, due_day, billing_cycle, cycle_type, expected_amount, current_balance, interest_rate, active) VALUES (?, 'Card', 10, 'monthly', 'monthly', 10000, 40000, 0, 1)",
  ).run(userId).lastInsertRowid;
  const bill = db.prepare('SELECT * FROM bills WHERE id = ?').get(billId);

  const manualId = db.prepare(
    "INSERT INTO payments (bill_id, amount, paid_date, method, payment_source, balance_delta) VALUES (?, 10000, '2026-06-10', 'manual', 'manual', -10000)",
  ).run(billId).lastInsertRowid;
  // Bank payment for the same bill/cycle (a matched SimpleFIN transaction).
  const bankId = db.prepare(
    "INSERT INTO payments (bill_id, amount, paid_date, method, payment_source, transaction_id) VALUES (?, 10000, '2026-06-12', 'bank', 'transaction_match', 777)",
  ).run(billId).lastInsertRowid;
  const bankPayment = db.prepare('SELECT * FROM payments WHERE id = ?').get(bankId);

  const activeCount = () => db.prepare(
    `SELECT COUNT(*) c FROM payments WHERE bill_id = ? AND deleted_at IS NULL AND ${accountingActiveSql()}`,
  ).get(billId).c;

  // Both currently count — the double-count we must resolve.
  assert.equal(activeCount(), 2);

  const { overridden } = markProvisionalManualPaymentsOverridden(db, bill, bankPayment);
  assert.equal(overridden, 1, 'the one provisional manual payment is overridden');

  const manualAfter = db.prepare('SELECT * FROM payments WHERE id = ?').get(manualId);
  assert.equal(manualAfter.accounting_excluded, 1);
  assert.equal(manualAfter.overridden_by_payment_id, bankId);
  assert.equal(manualAfter.balance_delta, null, 'overridden payment no longer holds a balance delta');
  assert.equal(activeCount(), 1, 'only the bank payment counts now — no double count');
  // Its balance effect was reversed: $400 → $500.
  assert.equal(db.prepare('SELECT current_balance FROM bills WHERE id = ?').get(billId).current_balance, 50000);

  // Bank override removed → the manual payment counts again and re-applies its balance.
  const { reactivated } = reactivatePaymentsOverriddenBy(db, bankId);
  assert.equal(reactivated, 1);
  const manualReactivated = db.prepare('SELECT * FROM payments WHERE id = ?').get(manualId);
  assert.equal(manualReactivated.accounting_excluded, 0);
  assert.equal(manualReactivated.overridden_by_payment_id, null);
  assert.equal(manualReactivated.balance_delta, -10000, 'balance delta re-applied');
  assert.equal(db.prepare('SELECT current_balance FROM bills WHERE id = ?').get(billId).current_balance, 40000, '$500 → $400 again');
});

test.after(() => {
  closeDb();
  for (const s of ['', '-wal', '-shm']) { try { fs.rmSync(dbPath + s); } catch {} }
});