Testing Your CRUD Endpoints¶

CRUD is exactly the kind of code that benefits from tests: clear inputs, clear outputs, lots of edge cases.

The Testing Pyramid for an API¶

Unit-Test the Pure Bits¶

Validation and authorization are pure functions — test them in isolation:

1test("rejects empty title", () => {
2  const r = CreateTask.safeParse({ title: "" });
3  expect(r.success).toBe(false);
4});
5
6test("non-owner cannot edit", () => {
7  expect(canEdit(user, otherUsersTask)).toBe(false);
8});

Integration-Test the Endpoints¶

Hit the real handler against a real (test) database and assert status + body:

1test("POST /tasks creates a task", async () => {
2  const res = await app.inject({
3    method: "POST",
4    url: "/api/v1/tasks",
5    headers: auth(user),
6    payload: { title: "Test" },
7  });
8  expect(res.statusCode).toBe(201);
9  expect(res.json().data.title).toBe("Test");
10});

Cover the CRUD Matrix¶

For each resource, test the happy path and the failures:

Isolate Test Data¶

Each test should set up and tear down its own data (transaction rollback per test, or a truncate between runs). Tests that depend on each other's leftover rows are flaky tests.