Raise a ParserError for empty string in parse() (#965)

Previously it raised a confusing `ValueError: year 0 is out of range` error.

Author: SAY-5

src/pendulum/parsing/__init__.py

@@ -145,7 +145,7 @@ def _parse_common(text: str, **options: Any) -> datetime | date | time:
     month = 1
     day = 1
 
-    if not m:
+    if not m or not (m.group("date") or m.group("time")):
         raise ParserError("Invalid datetime string")
 
     if m.group("date"):

tests/parsing/test_parsing.py

@@ -684,6 +684,11 @@ def test_invalid():
         parse(text)
 
 
+def test_parse_empty_string():
+    with pytest.raises(ParserError):
+        parse("")
+
+
 def test_exif_edge_case():
     text = "2016:12:26 15:45:28"