fix: raise NumberFormatError for invalid string in NumberPattern.apply

CHANGES.rst

@@ -1,6 +1,15 @@
 Babel Changelog
 ===============
 
+Version 2.19.0 (Unreleased)
+----------------------------
+
+Bugfixes
+~~~~~~~~
+
+* Numbers: Raise ``NumberFormatError`` instead of ``decimal.InvalidOperation``
+  when formatting an invalid string value by @2025sl93041-gkb in :gh:`702`
+
 Version 2.18.0
 --------------
 

babel/numbers.py

@@ -664,7 +664,10 @@ def _get_compact_format(
     https://www.unicode.org/reports/tr35/tr35-45/tr35-numbers.html#Compact_Number_Formats.
     """
     if not isinstance(number, decimal.Decimal):
-        number = decimal.Decimal(str(number))
+        try:
+            number = decimal.Decimal(str(number))
+        except decimal.InvalidOperation as e:
+            raise NumberFormatError(f"{number!r} is not a valid number") from e
     if number.is_nan() or number.is_infinite():
         return number, None
     format = None
@@ -1477,7 +1480,10 @@ def apply(
         :raise UnsupportedNumberingSystemError: If the numbering system is not supported by the locale.
         """
         if not isinstance(value, decimal.Decimal):
-            value = decimal.Decimal(str(value))
+            try:
+                value = decimal.Decimal(str(value))
+            except decimal.InvalidOperation as e:
+                raise NumberFormatError(f"{value!r} is not a valid number") from e
 
         value = value.scaleb(self.scale)
 

tests/test_numbers.py

@@ -695,3 +695,10 @@ def test_issue_1076_fixes():
     assert numbers.format_compact_decimal(2345678, format_type="long", locale="ja") == "235万"
     # Swahili does not define an accounting currency format; root aliases it to the standard format.
     assert numbers.format_currency(-2, "USD", format_type="accounting", locale="sw") == "-US$\xa02.00"
+
+
+def test_number_pattern_apply_invalid_string_raises_number_format_error():
+    from unittest.mock import MagicMock
+    pattern = numbers.parse_pattern('0.###')
+    with pytest.raises(numbers.NumberFormatError, match="is not a valid number"):
+        pattern.apply('not_a_number', locale=MagicMock())