huawei_lte: support out of range values in default sensor formatter (#26052)

* Update sensor.py

Change regexp to cope with out of range values, ie "rssi" : ">=-51dBm".

* Add tests for format_default

* Fix black formatting

homeassistant/components/huawei_lte/sensor.py

@@ -137,7 +137,9 @@ def format_default(value):
     unit = None
     if value is not None:
         # Clean up value and infer unit, e.g. -71dBm, 15 dB
-        match = re.match(r"(?P<value>.+?)\s*(?P<unit>[a-zA-Z]+)\s*$", str(value))
+        match = re.match(
+            r"([>=<]*)(?P<value>.+?)\s*(?P<unit>[a-zA-Z]+)\s*$", str(value)
+        )
         if match:
             try:
                 value = float(match.group("value"))

tests/components/huawei_lte/test_sensor.py

@@ -0,0 +1,14 @@
+"""Huawei LTE sensor tests."""
+
+import pytest
+
+from homeassistant.components.huawei_lte import sensor
+
+
+@pytest.mark.parametrize(
+    ("value", "expected"),
+    (("-71 dBm", (-71, "dBm")), ("15dB", (15, "dB")), (">=-51dBm", (-51, "dBm"))),
+)
+def test_format_default(value, expected):
+    """Test that default formatter copes with expected values."""
+    assert sensor.format_default(value) == expected