Tweak template digit detection (#43621)

homeassistant/helpers/template.py

@@ -50,7 +50,7 @@ _ENVIRONMENT = "template.environment"
 
 _RE_JINJA_DELIMITERS = re.compile(r"\{%|\{\{|\{#")
 # Match "simple" ints and floats. -1.0, 1, +5, 5.0
-_IS_NUMERIC = re.compile(r"^[+-]?\d*(?:\.\d*)?$")
+_IS_NUMERIC = re.compile(r"^[+-]?(?!0\d)\d*(?:\.\d*)?$")
 
 _RESERVED_NAMES = {"contextfunction", "evalcontextfunction", "environmentfunction"}
 

tests/helpers/test_template.py

@@ -2421,11 +2421,17 @@ async def test_parse_result(hass):
         ("1e+100", "1e+100"),
         ("0xface", "0xface"),
         ("123", 123),
+        ("10", 10),
         ("123.0", 123.0),
         (".5", 0.5),
+        ("0.5", 0.5),
         ("-1", -1),
         ("-1.0", -1.0),
         ("+1", 1),
         ("5.", 5.0),
+        ("123_123_123", "123_123_123"),
+        # ("+48100200300", "+48100200300"),  # phone number
+        ("010", "010"),
+        ("0011101.00100001010001", "0011101.00100001010001"),
     ):
         assert template.Template(tpl, hass).async_render() == result