--

cool-RR · cool-RR · commit b6e317f0b209 · 2015-12-27T20:08:47.000+02:00
diff --git a/source_py3/python_toolbox/context_management/__init__.py b/source_py3/python_toolbox/context_management/__init__.py
@@ -123,6 +123,7 @@ def do_stuff():
 # that will cause it to be pickled by reference to the decorated function
 
 
+from .abstract_context_manager import AbstractContextManager
 from .context_manager_type_type import ContextManagerTypeType
 from .context_manager_type import ContextManagerType
 from .context_manager import ContextManager
diff --git a/source_py3/python_toolbox/context_management/abstract_context_manager.py b/source_py3/python_toolbox/context_management/abstract_context_manager.py
@@ -0,0 +1,41 @@
+# Copyright 2009-2015 Ram Rachum.
+# This program is distributed under the MIT license.
+
+import sys
+import types
+import abc
+
+from python_toolbox import decorator_tools
+
+from .base_classes.decorating_context_manager import DecoratingContextManager
+from .context_manager_type import ContextManagerType
+from .self_hook import SelfHook
+
+
+class AbstractContextManager(metaclass=abc.ABCMeta):
+    '''
+    blocktodo: add tests
+    '''
+    @abc.abstractmethod
+    def __enter__(self):
+        '''Prepare for suite execution.'''
+
+    
+    @abc.abstractmethod
+    def __exit__(self, exc_type, exc_value, exc_traceback):
+        '''Cleanup after suite execution.'''
+    
+    @classmethod
+    def __subclasshook__(cls, candidate_class):
+        if cls is AbstractContextManager:
+            return (
+                hasattr(candidate_class, '__enter__') and
+                candidate_class.__enter__ is not none and 
+                hasattr(candidate_class, '__exit__') and
+                candidate_class.__exit__ is not none 
+            )
+        else:
+            return NotImplemented
+
+
+        
diff --git a/source_py3/python_toolbox/context_management/context_manager.py b/source_py3/python_toolbox/context_management/context_manager.py
@@ -7,12 +7,14 @@
 
 from python_toolbox import decorator_tools
 
+from .abstract_context_manager import AbstractContextManager
 from .base_classes.decorating_context_manager import DecoratingContextManager
 from .context_manager_type import ContextManagerType
 from .self_hook import SelfHook
 
 
-class ContextManager(DecoratingContextManager, metaclass=ContextManagerType):
+class ContextManager(AbstractContextManager, DecoratingContextManager,
+                     metaclass=ContextManagerType):
     '''
     Allows running preparation code before a given suite and cleanup after.
     
diff --git a/source_py3/python_toolbox/context_management/functions.py b/source_py3/python_toolbox/context_management/functions.py
@@ -106,11 +106,11 @@ def __init__(self, wrapped_context_manager):
             
     @classmethod
     def _wrap_context_manager_or_class(cls, thing):
-        if hasattr(type(thing), '__enter__'):
-            # It's a context manager.
+        from .abstract_context_manager import AbstractContextManager
+        if isinstance(thing, AbstractContextManager):
             return cls(thing)
         else:
-            assert issubclass(thing, ContextManager)
+            assert issubclass(thing, AbstractContextManager)
             # It's a context manager class.
             property_name = '__%s_context_manager_%s' % (
                 thing.__name__,
