Refactor code structure for improved readability and maintainability

tests/unit/test_api_contract.py

@@ -0,0 +1,77 @@
+import uuid
+from collections.abc import AsyncIterator
+
+import httpx2
+import pytest
+from fastapi import FastAPI
+
+from app.api import router
+from app.auth import get_settings
+from app.config import Settings
+
+
+@pytest.fixture
+async def client() -> AsyncIterator[httpx2.AsyncClient]:
+    app = FastAPI()
+    app.include_router(router)
+    app.dependency_overrides[get_settings] = lambda: Settings(api_key="change-me")
+    transport = httpx2.ASGITransport(app=app)
+    async with httpx2.AsyncClient(
+        transport=transport,
+        base_url="http://testserver",
+    ) as test_client:
+        yield test_client
+
+
+async def test_get_payment_requires_api_key(client: httpx2.AsyncClient) -> None:
+    response = await client.get(f"/api/v1/payments/{uuid.uuid4()}")
+
+    assert response.status_code == 401
+    assert response.json() == {"detail": "Invalid or missing API key"}
+
+
+async def test_get_payment_rejects_wrong_api_key(client: httpx2.AsyncClient) -> None:
+    response = await client.get(
+        f"/api/v1/payments/{uuid.uuid4()}",
+        headers={"X-API-Key": "wrong-key"},
+    )
+
+    assert response.status_code == 401
+
+
+async def test_create_payment_requires_idempotency_key(client: httpx2.AsyncClient) -> None:
+    response = await client.post(
+        "/api/v1/payments",
+        headers={"X-API-Key": "change-me"},
+        json={
+            "amount": "100.00",
+            "currency": "RUB",
+            "description": "Test payment",
+            "metadata": {},
+            "webhook_url": "https://example.com/webhook",
+        },
+    )
+
+    assert response.status_code == 422
+    assert response.json()["detail"][0]["loc"] == ["header", "Idempotency-Key"]
+
+
+async def test_create_payment_rejects_unsupported_currency(
+    client: httpx2.AsyncClient,
+) -> None:
+    response = await client.post(
+        "/api/v1/payments",
+        headers={
+            "X-API-Key": "change-me",
+            "Idempotency-Key": "test-key",
+        },
+        json={
+            "amount": "100.00",
+            "currency": "GBP",
+            "description": "Test payment",
+            "metadata": {},
+            "webhook_url": "https://example.com/webhook",
+        },
+    )
+
+    assert response.status_code == 422