Fix for issue #27 by stevepm@google.com / steve.middlekauff@gmail.com

git-svn-id: http://pymox.googlecode.com/svn/trunk@55 b1010a0a-674b-0410-b734-77272b80c875

3 files changed, 56 insertions, 4 deletions

diff --git a/mox.py b/mox.py
index 14ea121..a4a4fb5 100755
--- a/mox.py
+++ b/mox.py
@@ -899,8 +899,17 @@ class MethodSignatureChecker(object):
     if inspect.ismethod(self._method):
       # The extra param accounts for the bound instance.
       if len(params) == len(self._args) + 1:
-        clazz = getattr(self._method, 'im_class', None)
-        if isinstance(params[0], clazz) or params[0] == clazz:
+        expected = getattr(self._method, 'im_class', None)
+
+        # Check if the param is an instance of the expected class,
+        # or check equality (useful for checking Comparators).
+        if isinstance(params[0], expected) or params[0] == expected:
+          params = params[1:]
+        # If the IsA() comparator is being used, we need to check the
+        # inverse of the usual case - that the given instance is a subclass
+        # of the expected class.  For example, the code under test does
+        # late binding to a subclass.
+        elif isinstance(params[0], IsA) and params[0]._IsSubClass(expected):
           params = params[1:]
 
     # Check that each positional param is valid.
@@ -1284,8 +1293,26 @@ class IsA(Comparator):
       # things like cStringIO.StringIO.
       return type(rhs) == type(self._class_name)
 
+  def _IsSubClass(self, clazz):
+    """Check to see if the IsA comparators class is a subclass of clazz.
+
+    Args:
+      # clazz: a class object
+
+    Returns:
+      bool
+    """
+
+    try:
+      return issubclass(self._class_name, clazz)
+    except TypeError:
+      # Check raw types if there was a type error.  This is helpful for
+      # things like cStringIO.StringIO.
+      return type(clazz) == type(self._class_name)
+
   def __repr__(self):
-    return str(self._class_name)
+    return 'mox.IsA(%s) ' % str(self._class_name)
+
 
 class IsAlmost(Comparator):
   """Comparison class used to check whether a parameter is nearly equal
diff --git a/mox_test.py b/mox_test.py
index 611f8fb..bb684de 100755
--- a/mox_test.py
+++ b/mox_test.py
@@ -1575,6 +1575,20 @@ class MoxTest(unittest.TestCase):
     self.mox.UnsetStubs()
     self.assertEquals('foo', actual)
 
+  def testStubOutMethod_CalledAsUnboundMethod_Subclass_Comparator(self):
+    print 'this test'
+    self.mox.StubOutWithMock(mox_test_helper.TestClassFromAnotherModule, 'Value')
+    mox_test_helper.TestClassFromAnotherModule.Value(
+        mox.IsA(mox_test_helper.ChildClassFromAnotherModule)).AndReturn('foo')
+    self.mox.ReplayAll()
+
+    instance = mox_test_helper.ChildClassFromAnotherModule()
+    actual = mox_test_helper.TestClassFromAnotherModule.Value(instance)
+
+    self.mox.VerifyAll()
+    self.mox.UnsetStubs()
+    self.assertEquals('foo', actual)
+
   def testStubOutMethod_CalledAsUnboundMethod_ActualInstance(self):
     instance = TestClass()
     self.mox.StubOutWithMock(TestClass, 'OtherValidCall')
@@ -1599,7 +1613,6 @@ class MoxTest(unittest.TestCase):
     self.assertRaises(mox.UnexpectedMethodCallError,
                       TestClass.OtherValidCall, "wrong self")
 
-
     self.mox.VerifyAll()
     self.mox.UnsetStubs()
 
diff --git a/mox_test_helper.py b/mox_test_helper.py
index 60f72aa..0ccd484 100755
--- a/mox_test_helper.py
+++ b/mox_test_helper.py
@@ -95,6 +95,17 @@ class TestClassFromAnotherModule(object):
     return 'Not mock'
 
 
+class ChildClassFromAnotherModule(TestClassFromAnotherModule):
+  """A child class of TestClassFromAnotherModule.
+
+  Used to test stubbing out unbound methods, where child classes
+  are eventually bound.
+  """
+
+  def __init__(self):
+    TestClassFromAnotherModule.__init__(self)
+
+
 class CallableClass(object):
 
   def __init__(self, one, two, nine=None):
@@ -110,6 +121,7 @@ class CallableClass(object):
 def MyTestFunction(one, two, nine=None):
   pass
 
+
 class ExampleClass(object):
   def TestMethod(self, one, two, nine=None):
     pass