Derive all other future.types metaclasses from BaseNewObject and modify BaseNewObject __instancecheck__ to attempt to get test_types_isinstance_newobject() working

Author: edschofield

future/tests/test_object.py

@@ -162,7 +162,6 @@ class C(A):
         self.assertFalse(isinstance(b, C))
         self.assertTrue(isinstance(c, C))
 
-    @unittest.expectedFailure
     def test_types_isinstance_newobject(self):
         a = list()
         b = dict()
@@ -191,8 +190,8 @@ class G(F):
         g = G()
         self.assertTrue(isinstance(g, object))
 
-        def h():
-            return
+        class H():
+            pass
         h = H()
         self.assertTrue(isinstance(h, object))
 

future/types/newbytes.py

@@ -11,7 +11,7 @@
 
 from future.utils import istext, isbytes, PY3, with_metaclass
 from future.types import no, issubset
-from future.types.newobject import newobject
+from future.types.newobject import newobject, BaseNewObject
 
 
 _builtin_bytes = bytes
@@ -21,7 +21,7 @@
     unicode = str
 
 
-class BaseNewBytes(type):
+class BaseNewBytes(BaseNewObject):
     def __instancecheck__(cls, instance):
         if cls == newbytes:
             return isinstance(instance, _builtin_bytes)

future/types/newdict.py

@@ -19,14 +19,14 @@
 import sys
 
 from future.utils import with_metaclass
-from future.types.newobject import newobject
+from future.types.newobject import newobject, BaseNewObject
 
 
 _builtin_dict = dict
 ver = sys.version_info[:2]
 
 
-class BaseNewDict(type):
+class BaseNewDict(BaseNewObject):
     def __instancecheck__(cls, instance):
         if cls == newdict:
             return isinstance(instance, _builtin_dict)

future/types/newint.py

@@ -11,15 +11,15 @@
 import collections
 
 from future.types.newbytes import newbytes
-from future.types.newobject import newobject
+from future.types.newobject import newobject, BaseNewObject
 from future.utils import PY3, isint, istext, isbytes, with_metaclass, native
 
 
 if PY3:
     long = int
 
 
-class BaseNewInt(type):
+class BaseNewInt(BaseNewObject):
     def __instancecheck__(cls, instance):
         if cls == newint:
             # Special case for Py2 short or long int

future/types/newlist.py

@@ -16,14 +16,14 @@
 import copy
 
 from future.utils import with_metaclass
-from future.types.newobject import newobject
+from future.types.newobject import newobject, BaseNewObject
 
 
 _builtin_list = list
 ver = sys.version_info[:2]
 
 
-class BaseNewList(type):
+class BaseNewList(BaseNewObject):
     def __instancecheck__(cls, instance):
         if cls == newlist:
             return isinstance(instance, _builtin_list)

future/types/newobject.py

@@ -46,13 +46,15 @@ def __iter__(self):
 ver = sys.version_info[:2]
 
 
-# Dodgy: this messes up isinstance checks with subclasses of newobject
-# class BaseNewObject(type):
-#     def __instancecheck__(cls, instance):
-#         return isinstance(instance, _builtin_object)
+class BaseNewObject(type):
+    def __instancecheck__(cls, instance):
+        if cls == newobject:
+            return isinstance(instance, _builtin_object)
+        else:
+            return issubclass(instance.__class__, cls)
 
 
-class newobject(_builtin_object):
+class newobject(with_metaclass(BaseNewObject, _builtin_object)):
     """
     A magical object class that provides Python 2 compatibility methods::
         next

future/types/newstr.py

@@ -45,15 +45,15 @@
 
 from future.utils import PY3, istext, with_metaclass, isnewbytes
 from future.types import no, issubset
-from future.types.newobject import newobject
+from future.types.newobject import newobject, BaseNewObject
 
 
 if PY3:
     # We'll probably never use newstr on Py3 anyway...
     unicode = str
 
 
-class BaseNewStr(type):
+class BaseNewStr(BaseNewObject):
     def __instancecheck__(cls, instance):
         if cls == newstr:
             return isinstance(instance, unicode)