diff options
Diffstat (limited to 'mox3/stubout.py')
| -rw-r--r-- | mox3/stubout.py | 91 |
1 files changed, 49 insertions, 42 deletions
diff --git a/mox3/stubout.py b/mox3/stubout.py index 2681e5d..a02ed40 100644 --- a/mox3/stubout.py +++ b/mox3/stubout.py @@ -12,7 +12,6 @@ # See the License for the specific language governing permissions and # limitations under the License. # -# # This is a fork of the pymox library intended to work with Python 3. # The file was modified by quermit@gmail.com and dawid.fatyga@gmail.com @@ -21,16 +20,17 @@ 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() + You want os.path.exists() to always return true during testing. - 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. + 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): @@ -42,24 +42,25 @@ class StubOutForTesting(object): 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. + """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__)): @@ -86,20 +87,22 @@ class StubOutForTesting(object): 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. + # 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): + 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. + """Reverses all the SmartSet() calls. + Restores 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() @@ -109,11 +112,13 @@ class StubOutForTesting(object): 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. + """Replace child_name's old definition with new_child. + + Replace definiion 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. @@ -131,13 +136,15 @@ class StubOutForTesting(object): 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. + """Reverses all the Set() calls. + Restores 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) + # same arguments repeatedly (want the original call to be last one + # undone) self.cache.reverse() for (parent, old_child, child_name) in self.cache: |