"""Milestone 0.1 smoke tests.

Proves:
- `/healthz` returns 200 without any dependency access.
- Every response carries an `X-Request-ID` header (RequestIdMiddleware wired).
- The header is echoed back when the caller supplies one.
"""

from __future__ import annotations

from fastapi.testclient import TestClient


def test_healthz_returns_ok(client: TestClient) -> None:
    r = client.get("/healthz")
    assert r.status_code == 200
    assert r.json() == {"status": "ok"}


def test_response_carries_request_id(client: TestClient) -> None:
    r = client.get("/healthz")
    assert "x-request-id" in {k.lower() for k in r.headers}
    req_id = r.headers["X-Request-ID"]
    assert req_id
    assert len(req_id) >= 8


def test_incoming_request_id_is_honoured(client: TestClient) -> None:
    r = client.get("/healthz", headers={"X-Request-ID": "test-req-abcd"})
    assert r.headers["X-Request-ID"] == "test-req-abcd"