test: add update and 404 tests for sources API

backend/tests/test_sources.py

@@ -62,3 +62,38 @@ async def test_delete_source():
     async with AsyncClient(app=app, base_url="http://test") as ac:
         get_resp = await ac.get(f"/api/sources/{source_id}")
     assert get_resp.status_code == 404
+
+@pytest.mark.asyncio
+async def test_update_source():
+    async with AsyncClient(app=app, base_url="http://test") as ac:
+        create_resp = await ac.post("/api/sources/", json={
+            "name": "Original Name",
+            "type": "local",
+            "config": {"path": "/tmp/test"}
+        })
+        source_id = create_resp.json()["id"]
+        
+        response = await ac.put(f"/api/sources/{source_id}", json={
+            "name": "Updated Name"
+        })
+    assert response.status_code == 200
+    assert response.json()["name"] == "Updated Name"
+    assert response.json()["type"] == "local"  # Unchanged
+
+@pytest.mark.asyncio
+async def test_get_source_not_found():
+    async with AsyncClient(app=app, base_url="http://test") as ac:
+        response = await ac.get("/api/sources/99999")
+    assert response.status_code == 404
+
+@pytest.mark.asyncio
+async def test_update_source_not_found():
+    async with AsyncClient(app=app, base_url="http://test") as ac:
+        response = await ac.put("/api/sources/99999", json={"name": "Test"})
+    assert response.status_code == 404
+
+@pytest.mark.asyncio
+async def test_delete_source_not_found():
+    async with AsyncClient(app=app, base_url="http://test") as ac:
+        response = await ac.delete("/api/sources/99999")
+    assert response.status_code == 404