Fix handling of only one wind component in API request

metobsapi/data_api.py

@@ -75,10 +75,11 @@ def handle_symbols(symbols: list[str]):
         # detecting 'wind_direction', otherwise we don't know we need to readd it
         influx_to_requested_symbols[f"{site}.{inst}.{influx_name}"] = symbol
 
+        influx_symbols.setdefault((site, inst), [])
         if s == "wind_direction":
             add_winds.add((site, inst))
             continue
-        influx_symbols.setdefault((site, inst), []).append(influx_name)
+        influx_symbols[(site, inst)].append(influx_name)
 
     # Add the symbols needed to compute the wind_speed and wind_direction
     for site, inst in add_winds:

metobsapi/tests/test_data_api.py

@@ -402,6 +402,22 @@ def test_wind_speed_direction_json(symbols, client):
     assert len(list(res["results"]["data"].keys())) == len(symbols)
 
 
+@pytest.mark.usefixtures("influxdb_wind_fields_9_values")
+def test_wind_direction_only_json(client):
+    symbols = ["wind_direction"]
+    symbol_param = ":".join(symbols)
+    site_inst_params = "&site=aoss&inst=tower"
+
+    res = client.get(f"/api/data.json?symbols={symbol_param}{site_inst_params}&begin=-00:10:00&order=column")
+    res = json.loads(res.data.decode())
+    assert res["code"] == 200
+    assert res["num_results"] == 9
+    for symbol_name in symbols:
+        assert symbol_name in res["results"]["data"]
+        assert not np.isnan(res["results"]["data"][symbol_name]).all()
+    assert len(list(res["results"]["data"].keys())) == len(symbols)
+
+
 def test_one_symbol_two_insts_json_row(client, mock_influxdb_query):
     fake_result = _fake_data(
         "1m",