Fixed failing doctests on Python 3.7 due to changed repr of datetime.…

…timedelta

spans/_compat.py

@@ -1,9 +1,11 @@
 """Compatibility module for python 3"""
 
+import re
 import sys
 
 __all__ = [
     "add_metaclass",
+    "fix_timedelta_repr",
     "is_python2",
     "iter_range",
     "bstr",
@@ -62,3 +64,33 @@ def wrapper(cls):
 
         return metaclass(cls.__name__, cls.__bases__, orig_vars)
     return wrapper
+
+
+def fix_timedelta_repr(func):
+    """
+    Account repr change for timedelta in Python 3.7 and above in docstrings.
+
+    This is needed to make some doctests pass on Python 3.7 and above. This
+    change was introduced by `bpo-30302 <https://bugs.python.org/issue30302>`_
+    """
+    # We don't need to do anything if we're not on 3.7 or above
+    if version < (3, 7):
+        return func
+
+    def fix_timedelta(match):
+        values = match.group(1).split(", ")
+        param_repr = ", ".join(
+            "{}={}".format(param, value)
+            for param, value in zip(("days", "seconds", "microseconds"), values)
+            if value != "0"
+        )
+
+        # If we have a zero length timedelta it should be represented as
+        # timedelta(0), i.e. without named parameters
+        if not param_repr:
+            param_repr = "0"
+
+        return "timedelta({})".format(param_repr)
+
+    func.__doc__ = re.sub(r"timedelta\(([^)]+)\)", fix_timedelta, func.__doc__)
+    return func

spans/settypes.py

@@ -1,6 +1,6 @@
 from itertools import chain
 
-from ._compat import add_metaclass
+from ._compat import add_metaclass, fix_timedelta_repr
 from ._utils import PartialOrderingMixin
 from .types import Range
 from .types import *
@@ -666,6 +666,7 @@ class datetimerangeset(RangeSet):
     type = datetimerange
 
 
+@fix_timedelta_repr
 class timedeltarangeset(RangeSet):
     """
     Range set that operates on :class:`~spans.types.timedeltarange`.

spans/types.py

@@ -1320,6 +1320,7 @@ class datetimerange(Range, OffsetableRangeMixin):
     offset_type = timedelta
 
 
+@fix_timedelta_repr
 class timedeltarange(Range, OffsetableRangeMixin):
     """
     Range that operates on datetime's timedelta class.

tests/test_compat.py

@@ -0,0 +1,24 @@
+import pytest
+import sys
+
+from spans._compat import fix_timedelta_repr
+
+
+@pytest.mark.parametrize("original, patched", [
+    ("timedelta(0)", "timedelta(0)"),
+    ("timedelta(1)", "timedelta(days=1)"),
+    ("timedelta(2)", "timedelta(days=2)"),
+    ("timedelta(1, 2, 3)", "timedelta(days=1, seconds=2, microseconds=3)"),
+    ("timedelta(0, 1)", "timedelta(seconds=1)"),
+    ("timedelta(0, 0, 1)", "timedelta(microseconds=1)"),
+    ("foobar", "foobar"),
+])
+def test_timedelta_repr_fix(original, patched):
+    class Example(object):
+        __doc__ = original
+
+    if sys.version_info < (3, 7):
+        # Ensure that docstrings are left as they are on version 3.6 and below
+        assert fix_timedelta_repr(Example).__doc__ == original
+    else:
+        assert fix_timedelta_repr(Example).__doc__ == patched