— intelligent edge cases

Tests your team forgot to write

Null inputs, injection payloads, oversized bodies, race conditions, Unicode chaos — generated and ready to drop in.

Null & Undefined

Jest

createInvoice handles null line items

test('createInvoice rejects null lineItems', async () => {
  await expect(createInvoice({ lineItems: null }))
    .rejects.toThrow(/lineItems must be an array/);
});

Injection

Jest

Login resists SQL injection in email field

test("login is safe against SQLi payloads", async () => {
  const res = await api.post('/login', {
    email: "' OR 1=1 --",
    password: 'x',
  });
  expect(res.status).toBe(401);
});

Oversized Payload

Pytest

Upload rejects > 25MB body

def test_upload_rejects_oversized(client):
    big = b"a" * (26 * 1024 * 1024)
    r = client.post("/upload", data=big)
    assert r.status_code == 413

Unicode

Jest

Username accepts emoji & RTL combining marks

test('username supports emoji + RTL', () => {
  expect(validateUsername('شيرين🌸')).toBe(true);
  expect(validateUsername('a\u0301'.repeat(50))).toBe(false);
});

Race Condition

Jest

Concurrent charge attempts settle once

test('double-submit charges only once', async () => {
  const [a, b] = await Promise.all([
    charge(order), charge(order),
  ]);
  expect([a.ok, b.ok].filter(Boolean)).toHaveLength(1);
});

Auth

Postman

Expired JWT is rejected

pm.test("expired token -> 401", () => {
  pm.response.to.have.status(401);
  pm.expect(pm.response.json().error).to.eql("token_expired");
});

Malformed JSON

Pytest

Webhook returns 400 on broken JSON

def test_webhook_bad_json(client):
    r = client.post("/webhook", data="{not json", headers={"Content-Type":"application/json"})
    assert r.status_code == 400

XSS

Jest

Cart escapes <script> in product name

test('cart escapes script tags', () => {
  document.body.innerHTML = render({ name: '<script>x</script>' });
  expect(document.querySelector('script')).toBeNull();
});