debt_calc/tests.html at main · paraserv/debt_calc · GitHub

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<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8" />
  <meta name="viewport" content="width=device-width, initial-scale=1" />
  <title>Tests - Advanced Debt Payoff Calculator</title>
  <style>
    body { font-family: system-ui, sans-serif; margin: 20px; }
    .pass { color: #16a34a; }
    .fail { color: #dc2626; }
    pre { background: #0b1220; color: #e5e7eb; padding: 12px; border-radius: 6px; }
  </style>
</head>
<body>
  <h1>Unit Tests</h1>
  <div id="results"></div>
  <div id="tests-status" data-done="false" style="display:none"></div>
  <script>
    // Lightweight test helper
    const tests = [];
    function test(name, fn) { tests.push({ name, fn }); }
    function assertAlmostEqual(a, b, eps = 1e-6) {
      if (Math.abs(a - b) > eps) throw new Error(`Expected ${a} ≈ ${b}`);
    }
    function assertEqual(a, b) { if (a !== b) throw new Error(`Expected ${a} === ${b}`); }

    // Import functions by recreating minimal copies (kept in sync with main file)
    function calculateMonthlyInterest(balance, rate) { return balance * (rate / 100 / 12); }
    function calculateCFI(balance, minPayment, rate) {
      if (!minPayment || minPayment === 0) return Infinity;
      const monthlyInterest = calculateMonthlyInterest(balance, rate);
      const principal = minPayment - monthlyInterest;
      if (principal <= 0) return Infinity;
      return balance / principal;
    }

    test('monthly interest basic', () => {
      assertAlmostEqual(calculateMonthlyInterest(1200, 12), 12);
      assertAlmostEqual(calculateMonthlyInterest(0, 20), 0);
    });

    test('CFI with sufficient principal', () => {
      const cfi = calculateCFI(1000, 50, 12);
      if (!isFinite(cfi)) throw new Error('CFI should be finite');
    });

    test('CFI Infinity when payment <= interest', () => {
      const cfi = calculateCFI(1000, 5, 30); // interest > payment
      if (cfi !== Infinity) throw new Error('CFI expected Infinity');
    });

    (async function run(){
      const out = document.getElementById('results');
      for (const t of tests) {
        const div = document.createElement('div');
        try {
          await t.fn();
          div.textContent = `✓ ${t.name}`;
          div.className = 'pass';
        } catch (e) {
          div.textContent = `✗ ${t.name} -> ${e.message}`;
          div.className = 'fail';
        }
        out.appendChild(div);
      }
      document.getElementById('tests-status').dataset.done = 'true';
    })();
  </script>
</body>
</html>