Fixed ValueError when the target callable has a default keyword argument that wasn't overridden (fixes #79)

3 files changed, 15 insertions, 2 deletions

diff --git a/apscheduler/util.py b/apscheduler/util.py
index 988f942..063a6c1 100644
--- a/apscheduler/util.py
+++ b/apscheduler/util.py
@@ -343,16 +343,17 @@ def check_callable_args(func, args, kwargs):
             return  # getargspec() doesn't work certain callables
 
         argspec_args = argspec.args if not ismethod(func) else argspec.args[1:]
+        arg_defaults = dict(zip(reversed(argspec_args), argspec.defaults or ()))
         has_varargs = bool(argspec.varargs)
         has_var_kwargs = bool(argspec.keywords)
-        for arg, default in six.moves.zip_longest(argspec_args, argspec.defaults or (), fillvalue=undefined):
+        for arg in argspec_args:
             if arg in unmatched_kwargs and unmatched_args:
                 pos_kwargs_conflicts.append(arg)
             elif unmatched_args:
                 del unmatched_args[0]
             elif arg in unmatched_kwargs:
                 unmatched_kwargs.remove(arg)
-            elif default is undefined:
+            elif arg not in arg_defaults:
                 unsatisfied_args.append(arg)
 
     # Make sure there are no conflicts between args and kwargs
diff --git a/docs/versionhistory.rst b/docs/versionhistory.rst
index 5d79ee3..819e329 100644
--- a/docs/versionhistory.rst
+++ b/docs/versionhistory.rst
@@ -5,6 +5,12 @@ To find out how to migrate your application from a previous version of
 APScheduler, see the :doc:`migration section <migration>`.
 
 
+3.0.2
+-----
+
+* Fixed ValueError when the target callable has a default keyword argument that wasn't overridden
+
+
 3.0.1
 -----
 
diff --git a/tests/test_util.py b/tests/test_util.py
index a416297..6908bc3 100644
--- a/tests/test_util.py
+++ b/tests/test_util.py
@@ -257,6 +257,12 @@ class TestCheckCallableArgs(object):
         exc = pytest.raises(ValueError, check_callable_args, lambda x, y, z: None, [1], {'y': 0})
         assert str(exc.value) == 'The following arguments have not been supplied: z'
 
+    def test_default_args(self, use_signature):
+        """Tests that default values for arguments are properly taken into account."""
+
+        exc = pytest.raises(ValueError, check_callable_args, lambda x, y, z=1: None, [1], {})
+        assert str(exc.value) == 'The following arguments have not been supplied: y'
+
     def test_conflicting_callable_args(self, use_signature):
         """
         Tests that attempting to schedule a job where the combination of args and kwargs are in conflict raises an