Avoid infinite loop in Datetime.bulk_create_datetimes by checking for positive timedelta

CONTRIBUTORS.rst

@@ -90,6 +90,7 @@ Patches and Suggestions
 -  Oleg Höfling `(hoefling)`_
 -  Nick Pope `(ngnpope)`_
 -  Arul Prabakaran `(arulprabakaran)`_
+-  Florian Kroiß `(Wooza)`_
 
 
 .. _(lk-geimfari): https://github.com/lk-geimfari
@@ -158,3 +159,4 @@ Patches and Suggestions
 .. _(hoefling): https://github.com/hoefling
 .. _(ngnpope): https://github.com/ngnpope
 .. _(arulprabakaran): https://github.com/arulprabakaran
+.. _(Wooza): https://github.com/Wooza

mimesis/providers/date.py

@@ -55,8 +55,9 @@ def bulk_create_datetimes(
         :param date_end: End of the range.
         :param kwargs: Keyword arguments for :py:class:`datetime.timedelta`
         :return: List of datetime objects
-        :raises: ValueError: When ``date_start``/``date_end`` not passed and
-            when ``date_start`` larger than ``date_end``.
+        :raises: ValueError: When ``date_start``/``date_end`` not passed,
+            when ``date_start`` larger than ``date_end`` or when the given
+            keywords for `datetime.timedelta` represent a non-positive timedelta.
         """
         dt_objects = []
 
@@ -66,6 +67,9 @@ def bulk_create_datetimes(
         if date_end < date_start:
             raise ValueError("date_start can not be larger than date_end")
 
+        if timedelta(**kwargs) <= timedelta():
+            raise ValueError("timedelta must be positive")
+
         while date_start <= date_end:
             date_start += timedelta(**kwargs)
             dt_objects.append(date_start)

tests/test_providers/test_datetime.py

@@ -45,6 +45,11 @@ def test_bulk_create_datetimes_error(self, _datetime):
         with pytest.raises(ValueError):
             _datetime.bulk_create_datetimes(None, None)
 
+        with pytest.raises(ValueError):
+            _datetime.bulk_create_datetimes(
+                date_start, date_start + datetime.timedelta(days=1)
+            )
+
     def test_year(self, _datetime):
         result = _datetime.year(minimum=2000, maximum=_datetime.CURRENT_YEAR)
         assert result >= 2000