diff options
Diffstat (limited to 'mox3/stubout.py')
| -rw-r--r-- | mox3/stubout.py | 238 |
1 files changed, 119 insertions, 119 deletions
diff --git a/mox3/stubout.py b/mox3/stubout.py index f956c3b..2681e5d 100644 --- a/mox3/stubout.py +++ b/mox3/stubout.py @@ -20,126 +20,126 @@ import inspect class StubOutForTesting(object): - """Sample Usage: - You want os.path.exists() to always return true during testing. - - stubs = StubOutForTesting() - stubs.Set(os.path, 'exists', lambda x: 1) - ... - stubs.UnsetAll() - - The above changes os.path.exists into a lambda that returns 1. Once - the ... part of the code finishes, the UnsetAll() looks up the old value - of os.path.exists and restores it. - - """ - def __init__(self): - self.cache = [] - self.stubs = [] - - def __del__(self): - self.SmartUnsetAll() - self.UnsetAll() - - def SmartSet(self, obj, attr_name, new_attr): - """Replace obj.attr_name with new_attr. This method is smart and works - at the module, class, and instance level while preserving proper - inheritance. It will not stub out C types however unless that has been - explicitly allowed by the type. - - This method supports the case where attr_name is a staticmethod or a - classmethod of obj. - - Notes: - - If obj is an instance, then it is its class that will actually be - stubbed. Note that the method Set() does not do that: if obj is - an instance, it (and not its class) will be stubbed. - - The stubbing is using the builtin getattr and setattr. So, the __get__ - and __set__ will be called when stubbing (TODO: A better idea would - probably be to manipulate obj.__dict__ instead of getattr() and - setattr()). - - Raises AttributeError if the attribute cannot be found. - """ - if (inspect.ismodule(obj) or - (not inspect.isclass(obj) and attr_name in obj.__dict__)): - orig_obj = obj - orig_attr = getattr(obj, attr_name) - - else: - if not inspect.isclass(obj): - mro = list(inspect.getmro(obj.__class__)) - else: - mro = list(inspect.getmro(obj)) - - mro.reverse() - - orig_attr = None - - for cls in mro: - try: - orig_obj = cls - orig_attr = getattr(obj, attr_name) - except AttributeError: - continue - - if orig_attr is None: - raise AttributeError("Attribute not found.") - - # Calling getattr() on a staticmethod transforms it to a 'normal' function. - # We need to ensure that we put it back as a staticmethod. - old_attribute = obj.__dict__.get(attr_name) - if old_attribute is not None and isinstance(old_attribute, staticmethod): - orig_attr = staticmethod(orig_attr) - - self.stubs.append((orig_obj, attr_name, orig_attr)) - setattr(orig_obj, attr_name, new_attr) - - def SmartUnsetAll(self): - """Reverses all the SmartSet() calls, restoring things to their original - definition. Its okay to call SmartUnsetAll() repeatedly, as later calls - have no effect if no SmartSet() calls have been made. + """Sample Usage: + You want os.path.exists() to always return true during testing. - """ - self.stubs.reverse() - - for args in self.stubs: - setattr(*args) - - self.stubs = [] + stubs = StubOutForTesting() + stubs.Set(os.path, 'exists', lambda x: 1) + ... + stubs.UnsetAll() - def Set(self, parent, child_name, new_child): - """Replace child_name's old definition with new_child, in the context - of the given parent. The parent could be a module when the child is a - function at module scope. Or the parent could be a class when a class' - method is being replaced. The named child is set to new_child, while - the prior definition is saved away for later, when UnsetAll() is called. + The above changes os.path.exists into a lambda that returns 1. Once + the ... part of the code finishes, the UnsetAll() looks up the old value + of os.path.exists and restores it. - This method supports the case where child_name is a staticmethod or a - classmethod of parent. """ - old_child = getattr(parent, child_name) - - old_attribute = parent.__dict__.get(child_name) - if old_attribute is not None: - if isinstance(old_attribute, staticmethod): - old_child = staticmethod(old_child) - elif isinstance(old_attribute, classmethod): - old_child = classmethod(old_child.__func__) - - self.cache.append((parent, old_child, child_name)) - setattr(parent, child_name, new_child) - - def UnsetAll(self): - """Reverses all the Set() calls, restoring things to their original - definition. Its okay to call UnsetAll() repeatedly, as later calls have - no effect if no Set() calls have been made. - - """ - # Undo calls to Set() in reverse order, in case Set() was called on the - # same arguments repeatedly (want the original call to be last one undone) - self.cache.reverse() - - for (parent, old_child, child_name) in self.cache: - setattr(parent, child_name, old_child) - self.cache = [] + def __init__(self): + self.cache = [] + self.stubs = [] + + def __del__(self): + self.SmartUnsetAll() + self.UnsetAll() + + def SmartSet(self, obj, attr_name, new_attr): + """Replace obj.attr_name with new_attr. This method is smart and works + at the module, class, and instance level while preserving proper + inheritance. It will not stub out C types however unless that has been + explicitly allowed by the type. + + This method supports the case where attr_name is a staticmethod or a + classmethod of obj. + + Notes: + - If obj is an instance, then it is its class that will actually be + stubbed. Note that the method Set() does not do that: if obj is + an instance, it (and not its class) will be stubbed. + - The stubbing is using the builtin getattr and setattr. So, the __get__ + and __set__ will be called when stubbing (TODO: A better idea would + probably be to manipulate obj.__dict__ instead of getattr() and + setattr()). + + Raises AttributeError if the attribute cannot be found. + """ + if (inspect.ismodule(obj) or + (not inspect.isclass(obj) and attr_name in obj.__dict__)): + orig_obj = obj + orig_attr = getattr(obj, attr_name) + + else: + if not inspect.isclass(obj): + mro = list(inspect.getmro(obj.__class__)) + else: + mro = list(inspect.getmro(obj)) + + mro.reverse() + + orig_attr = None + + for cls in mro: + try: + orig_obj = cls + orig_attr = getattr(obj, attr_name) + except AttributeError: + continue + + if orig_attr is None: + raise AttributeError("Attribute not found.") + + # Calling getattr() on a staticmethod transforms it to a 'normal' function. + # We need to ensure that we put it back as a staticmethod. + old_attribute = obj.__dict__.get(attr_name) + if old_attribute is not None and isinstance(old_attribute, staticmethod): + orig_attr = staticmethod(orig_attr) + + self.stubs.append((orig_obj, attr_name, orig_attr)) + setattr(orig_obj, attr_name, new_attr) + + def SmartUnsetAll(self): + """Reverses all the SmartSet() calls, restoring things to their original + definition. Its okay to call SmartUnsetAll() repeatedly, as later calls + have no effect if no SmartSet() calls have been made. + + """ + self.stubs.reverse() + + for args in self.stubs: + setattr(*args) + + self.stubs = [] + + def Set(self, parent, child_name, new_child): + """Replace child_name's old definition with new_child, in the context + of the given parent. The parent could be a module when the child is a + function at module scope. Or the parent could be a class when a class' + method is being replaced. The named child is set to new_child, while + the prior definition is saved away for later, when UnsetAll() is called. + + This method supports the case where child_name is a staticmethod or a + classmethod of parent. + """ + old_child = getattr(parent, child_name) + + old_attribute = parent.__dict__.get(child_name) + if old_attribute is not None: + if isinstance(old_attribute, staticmethod): + old_child = staticmethod(old_child) + elif isinstance(old_attribute, classmethod): + old_child = classmethod(old_child.__func__) + + self.cache.append((parent, old_child, child_name)) + setattr(parent, child_name, new_child) + + def UnsetAll(self): + """Reverses all the Set() calls, restoring things to their original + definition. Its okay to call UnsetAll() repeatedly, as later calls have + no effect if no Set() calls have been made. + + """ + # Undo calls to Set() in reverse order, in case Set() was called on the + # same arguments repeatedly (want the original call to be last one undone) + self.cache.reverse() + + for (parent, old_child, child_name) in self.cache: + setattr(parent, child_name, old_child) + self.cache = [] |