Clean up

backend/tests/test_api.py

@@ -166,6 +166,21 @@ async def test_register_non_uuidv4_token(client: AsyncClient) -> None:
     assert resp.status_code == 400
 
 
+@pytest.mark.asyncio
+async def test_uuid_inputs_are_canonicalized(client: AsyncClient) -> None:
+    token = make_uuidv4()
+    upper_token = token.upper()
+    register_resp = await client.post("/api/v1/register", json={"token": upper_token})
+    assert register_resp.status_code == 200
+    assert register_resp.json() == {"user_id": token}
+
+    data_resp = await client.get(
+        "/api/v1/data",
+        headers={"Authorization": f"Bearer {upper_token}"},
+    )
+    assert data_resp.status_code == 200
+
+
 # ---------------------------------------------------------------------------
 # Auth / GET /data
 # ---------------------------------------------------------------------------
@@ -322,6 +337,34 @@ async def test_put_duplicate_page_id(client: AsyncClient) -> None:
 
     resp = await client.put("/api/v1/data", json=tree, headers=headers)
     assert resp.status_code == 400  # pydantic validation error → 400 bad_request per spec
+    assert resp.json() == {"error": "bad_request", "detail": "Validation failed"}
+
+
+@pytest.mark.asyncio
+async def test_put_cross_user_id_conflict_returns_409(client: AsyncClient) -> None:
+    first_token = make_uuidv4()
+    second_token = make_uuidv4()
+    await client.post("/api/v1/register", json={"token": first_token})
+    await client.post("/api/v1/register", json={"token": second_token})
+
+    tree = _make_tree()
+    first_resp = await client.put(
+        "/api/v1/data",
+        json=tree,
+        headers={"Authorization": f"Bearer {first_token}"},
+    )
+    assert first_resp.status_code == 204
+
+    second_resp = await client.put(
+        "/api/v1/data",
+        json=tree,
+        headers={"Authorization": f"Bearer {second_token}"},
+    )
+    assert second_resp.status_code == 409
+    assert second_resp.json() == {
+        "error": "conflict",
+        "detail": "Submitted IDs conflict with existing data",
+    }
 
 
 @pytest.mark.asyncio