add mqtt-fetch test

app/tests/test_web_route.py

@@ -7,6 +7,7 @@ from gen3plus.inverter_g3p import InverterG3P
 from test_inverter_g3p import FakeReader, FakeWriter, config_conn
 from cnf.config import Config
 from mock import patch
+from proxy import Proxy
 import os, errno
 
 pytest_plugins = ('pytest_asyncio',)
@@ -174,6 +175,16 @@ async def test_language_unknown(client):
     assert response.mimetype == 'text/html'
 
 
+@pytest.mark.asyncio
+async def test_mqtt_fetch(client, create_inverter):
+    """Test the mqtt-fetch route."""
+    _ = create_inverter
+    Proxy.class_init()
+
+    response = await client.get('/mqtt-fetch')
+    assert response.status_code == 200
+
+
 @pytest.mark.asyncio
 async def test_file_fetch(client, config_conn):
     """Test the data-fetch route."""