CHANGELOG

2012/02/13 Version 0.8.0

The only changes since 0.8rc2 are:

  • Improved repr of sentinel objects
  • ANY can be used for comparisons against call objects
  • The return value of the MagicMock __iter__ method can be set to any iterable and isn’t required to be an iterator

Full List of changes since 0.7:

mock 0.8.0 is the last version that will support Python 2.4.

  • Addition of mock_calls list for all calls (including magic methods and chained calls)
  • patch() and patch.object() now create a MagicMock instead of a Mock by default
  • The patchers (patch, patch.object and patch.dict), plus Mock and MagicMock, take arbitrary keyword arguments for configuration
  • New mock method configure_mock() for setting attributes and return values / side effects on the mock and its attributes
  • New mock assert methods assert_any_call() and assert_has_calls()
  • Implemented Autospeccing (recursive, lazy speccing of mocks with mocked signatures for functions/methods), as the autospec argument to patch
  • Added the create_autospec() function for manually creating ‘auto-specced’ mocks
  • patch.multiple() for doing multiple patches in a single call, using keyword arguments
  • Setting side_effect to an iterable will cause calls to the mock to return the next value from the iterable
  • New new_callable argument to patch and patch.object allowing you to pass in a class or callable object (instead of MagicMock) that will be called to replace the object being patched
  • Addition of NonCallableMock and NonCallableMagicMock, mocks without a __call__ method
  • Addition of mock_add_spec() method for adding (or changing) a spec on an existing mock
  • Protocol methods on MagicMock are magic mocks, and are created lazily on first lookup. This means the result of calling a protocol method is a MagicMock instead of a Mock as it was previously
  • Addition of attach_mock() method
  • Added ANY for ignoring arguments in assert_called_with() calls
  • Addition of call helper object
  • Improved repr for mocks
  • Improved repr for Mock.call_args and entries in Mock.call_args_list, Mock.method_calls and Mock.mock_calls
  • Improved repr for sentinel objects
  • patch lookup is done at use time not at decoration time
  • In Python 2.6 or more recent, dir on a mock will report all the dynamically created attributes (or the full list of attributes if there is a spec) as well as all the mock methods and attributes.
  • Module level FILTER_DIR added to control whether dir(mock) filters private attributes. True by default.
  • patch.TEST_PREFIX for controlling how patchers recognise test methods when used to decorate a class
  • Support for using Java exceptions as a side_effect on Jython
  • Mock call lists (call_args_list, method_calls & mock_calls) are now custom list objects that allow membership tests for “sub lists” and have a nicer representation if you str or print them
  • Mocks attached as attributes or return values to other mocks have calls recorded in method_calls and mock_calls of the parent (unless a name is already set on the child)
  • Improved failure messages for assert_called_with and assert_called_once_with
  • The return value of the MagicMock __iter__ method can be set to any iterable and isn’t required to be an iterator
  • Added the Mock API (assert_called_with etc) to functions created by mocksignature()
  • Tuples as well as lists can be used to specify allowed methods for spec & spec_set arguments
  • Calling stop on an unstarted patcher fails with a more meaningful error message
  • Renamed the internal classes Sentinel and SentinelObject to prevent abuse
  • BUGFIX: an error creating a patch, with nested patch decorators, won’t leave patches in place
  • BUGFIX: __truediv__ and __rtruediv__ not available as magic methods on mocks in Python 3
  • BUGFIX: assert_called_with / assert_called_once_with can be used with self as a keyword argument
  • BUGFIX: when patching a class with an explicit spec / spec_set (not a boolean) it applies “spec inheritance” to the return value of the created mock (the “instance”)
  • BUGFIX: remove the __unittest marker causing traceback truncation
  • Removal of deprecated patch_object
  • Private attributes _name, _methods, ‘_children’, _wraps and _parent (etc) renamed to reduce likelihood of clash with user attributes.
  • Added license file to the distribution

2012/01/10 Version 0.8.0 release candidate 2

  • Removed the configure keyword argument to create_autospec and allow arbitrary keyword arguments (for the Mock constructor) instead
  • Fixed ANY equality with some types in assert_called_with calls
  • Switched to a standard Sphinx theme (compatible with readthedocs.org)

2011/12/29 Version 0.8.0 release candidate 1

  • create_autospec on the return value of a mocked class will use __call__ for the signature rather than __init__
  • Performance improvement instantiating Mock and MagicMock
  • Mocks used as magic methods have the same type as their parent instead of being hardcoded to MagicMock

Special thanks to Julian Berman for his help with diagnosing and improving performance in this release.

2011/10/09 Version 0.8.0 beta 4

  • patch lookup is done at use time not at decoration time
  • When attaching a Mock to another Mock as a magic method, calls are recorded in mock_calls
  • Addition of attach_mock method
  • Renamed the internal classes Sentinel and SentinelObject to prevent abuse
  • BUGFIX: various issues around circular references with mocks (setting a mock return value to be itself etc)

2011/08/15 Version 0.8.0 beta 3

  • Mocks attached as attributes or return values to other mocks have calls recorded in method_calls and mock_calls of the parent (unless a name is already set on the child)
  • Addition of mock_add_spec method for adding (or changing) a spec on an existing mock
  • Improved repr for Mock.call_args and entries in Mock.call_args_list, Mock.method_calls and Mock.mock_calls
  • Improved repr for mocks
  • BUGFIX: minor fixes in the way mock_calls is worked out, especially for “intermediate” mocks in a call chain

2011/08/05 Version 0.8.0 beta 2

  • Setting side_effect to an iterable will cause calls to the mock to return the next value from the iterable
  • Added assert_any_call method
  • Moved assert_has_calls from call lists onto mocks
  • BUGFIX: call_args and all members of call_args_list are two tuples of (args, kwargs) again instead of three tuples of (name, args, kwargs)

2011/07/25 Version 0.8.0 beta 1

  • patch.TEST_PREFIX for controlling how patchers recognise test methods when used to decorate a class
  • Mock call lists (call_args_list, method_calls & mock_calls) are now custom list objects that allow membership tests for “sub lists” and have an assert_has_calls method for unordered call checks
  • callargs changed to always be a three-tuple of (name, args, kwargs)
  • Addition of mock_calls list for all calls (including magic methods and chained calls)
  • Extension of call object to support chained calls and callargs for better comparisons with or without names. call object has a call_list method for chained calls
  • Added the public instance argument to create_autospec
  • Support for using Java exceptions as a side_effect on Jython
  • Improved failure messages for assert_called_with and assert_called_once_with
  • Tuples as well as lists can be used to specify allowed methods for spec & spec_set arguments
  • BUGFIX: Fixed bug in patch.multiple for argument passing when creating mocks
  • Added license file to the distribution

2011/07/16 Version 0.8.0 alpha 2

  • patch.multiple for doing multiple patches in a single call, using keyword arguments
  • New new_callable argument to patch and patch.object allowing you to pass in a class or callable object (instead of MagicMock) that will be called to replace the object being patched
  • Addition of NonCallableMock and NonCallableMagicMock, mocks without a __call__ method
  • Mocks created by patch have a MagicMock as the return_value where a class is being patched
  • create_autospec can create non-callable mocks for non-callable objects. return_value mocks of classes will be non-callable unless the class has a __call__ method
  • autospec creates a MagicMock without a spec for properties and slot descriptors, because we don’t know the type of object they return
  • Removed the “inherit” argument from create_autospec
  • Calling stop on an unstarted patcher fails with a more meaningful error message
  • BUGFIX: an error creating a patch, with nested patch decorators, won’t leave patches in place
  • BUGFIX: __truediv__ and __rtruediv__ not available as magic methods on mocks in Python 3
  • BUGFIX: assert_called_with / assert_called_once_with can be used with self as a keyword argument
  • BUGFIX: autospec for functions / methods with an argument named self that isn’t the first argument no longer broken
  • BUGFIX: when patching a class with an explicit spec / spec_set (not a boolean) it applies “spec inheritance” to the return value of the created mock (the “instance”)
  • BUGFIX: remove the __unittest marker causing traceback truncation

2011/06/14 Version 0.8.0 alpha 1

mock 0.8.0 is the last version that will support Python 2.4.

  • The patchers (patch, patch.object and patch.dict), plus Mock and MagicMock, take arbitrary keyword arguments for configuration

  • New mock method configure_mock for setting attributes and return values / side effects on the mock and its attributes

  • In Python 2.6 or more recent, dir on a mock will report all the dynamically created attributes (or the full list of attributes if there is a spec) as well as all the mock methods and attributes.

  • Module level FILTER_DIR added to control whether dir(mock) filters private attributes. True by default. Note that vars(Mock()) can still be used to get all instance attributes and dir(type(Mock()) will still return all the other attributes (irrespective of FILTER_DIR)

  • patch and patch.object now create a MagicMock instead of a Mock by default

  • Added ANY for ignoring arguments in assert_called_with calls

  • Addition of call helper object

  • Protocol methods on MagicMock are magic mocks, and are created lazily on first lookup. This means the result of calling a protocol method is a MagicMock instead of a Mock as it was previously

  • Added the Mock API (assert_called_with etc) to functions created by mocksignature

  • Private attributes _name, _methods, ‘_children’, _wraps and _parent (etc) renamed to reduce likelihood of clash with user attributes.

  • Implemented auto-speccing (recursive, lazy speccing of mocks with mocked signatures for functions/methods)

    Limitations:

    • Doesn’t mock magic methods or attributes (it creates MagicMocks, so the magic methods are there, they just don’t have the signature mocked nor are attributes followed)
    • Doesn’t mock function / method attributes
    • Uses object traversal on the objects being mocked to determine types - so properties etc may be triggered
    • The return value of mocked classes (the ‘instance’) has the same call signature as the class __init__ (as they share the same spec)

    You create auto-specced mocks by passing autospec=True to patch.

    Note that attributes that are None are special cased and mocked without a spec (so any attribute / method can be used). This is because None is typically used as a default value for attributes that may be of some other type, and as we don’t know what type that may be we allow all access.

    Note that the autospec option to patch obsoletes the mocksignature option.

  • Added the create_autospec function for manually creating ‘auto-specced’ mocks

  • Removal of deprecated patch_object

2011/05/30 Version 0.7.2

  • BUGFIX: instances of list subclasses can now be used as mock specs
  • BUGFIX: MagicMock equality / inequality protocol methods changed to use the default equality / inequality. This is done through a side_effect on the mocks used for __eq__ / __ne__

2011/05/06 Version 0.7.1

Package fixes contributed by Michael Fladischer. No code changes.

  • Include template in package
  • Use isolated binaries for the tox tests
  • Unset executable bit on docs
  • Fix DOS line endings in getting-started.txt

2011/03/05 Version 0.7.0

No API changes since 0.7.0 rc1. Many documentation changes including a stylish new Sphinx theme.

The full set of changes since 0.6.0 are:

  • Python 3 compatibility
  • Ability to mock magic methods with Mock and addition of MagicMock with pre-created magic methods
  • Addition of mocksignature and mocksignature argument to patch and patch.object
  • Addition of patch.dict for changing dictionaries during a test
  • Ability to use patch, patch.object and patch.dict as class decorators
  • Renamed patch_object to patch.object (patch_object is deprecated)
  • Addition of soft comparisons: call_args, call_args_list and method_calls now return tuple-like objects which compare equal even when empty args or kwargs are skipped
  • patchers (patch, patch.object and patch.dict) have start and stop methods
  • Addition of assert_called_once_with method
  • Mocks can now be named (name argument to constructor) and the name is used in the repr
  • repr of a mock with a spec includes the class name of the spec
  • assert_called_with works with python -OO
  • New spec_set keyword argument to Mock and patch. If used, attempting to set an attribute on a mock not on the spec will raise an AttributeError
  • Mocks created with a spec can now pass isinstance tests (__class__ returns the type of the spec)
  • Added docstrings to all objects
  • Improved failure message for Mock.assert_called_with when the mock has not been called at all
  • Decorated functions / methods have their docstring and __module__ preserved on Python 2.4.
  • BUGFIX: mock.patch now works correctly with certain types of objects that proxy attribute access, like the django settings object
  • BUGFIX: mocks are now copyable (thanks to Ned Batchelder for reporting and diagnosing this)
  • BUGFIX: spec=True works with old style classes
  • BUGFIX: help(mock) works now (on the module). Can no longer use __bases__ as a valid sentinel name (thanks to Stephen Emslie for reporting and diagnosing this)
  • BUGFIX: side_effect now works with BaseException exceptions like KeyboardInterrupt
  • BUGFIX: reset_mock caused infinite recursion when a mock is set as its own return value
  • BUGFIX: patching the same object twice now restores the patches correctly
  • with statement tests now skipped on Python 2.4
  • Tests require unittest2 (or unittest2-py3k) to run
  • Tested with tox on Python 2.4 - 3.2, jython and pypy (excluding 3.0)
  • Added ‘build_sphinx’ command to setup.py (requires setuptools or distribute) Thanks to Florian Bauer
  • Switched from subversion to mercurial for source code control
  • Konrad Delong added as co-maintainer

2011/02/16 Version 0.7.0 RC 1

Changes since beta 4:

  • Tested with jython, pypy and Python 3.2 and 3.1
  • Decorated functions / methods have their docstring and __module__ preserved on Python 2.4
  • BUGFIX: mock.patch now works correctly with certain types of objects that proxy attribute access, like the django settings object
  • BUGFIX: reset_mock caused infinite recursion when a mock is set as its own return value

2010/11/12 Version 0.7.0 beta 4

  • patchers (patch, patch.object and patch.dict) have start and stop methods
  • Addition of assert_called_once_with method
  • repr of a mock with a spec includes the class name of the spec
  • assert_called_with works with python -OO
  • New spec_set keyword argument to Mock and patch. If used, attempting to set an attribute on a mock not on the spec will raise an AttributeError
  • Attributes and return value of a MagicMock are MagicMock objects
  • Attempting to set an unsupported magic method now raises an AttributeError
  • patch.dict works as a class decorator
  • Switched from subversion to mercurial for source code control
  • BUGFIX: mocks are now copyable (thanks to Ned Batchelder for reporting and diagnosing this)
  • BUGFIX: spec=True works with old style classes
  • BUGFIX: mocksignature=True can now patch instance methods via patch.object

2010/09/18 Version 0.7.0 beta 3

  • Using spec with MagicMock only pre-creates magic methods in the spec
  • Setting a magic method on a mock with a spec can only be done if the spec has that method
  • Mocks can now be named (name argument to constructor) and the name is used in the repr
  • mocksignature can now be used with classes (signature based on __init__) and callable objects (signature based on __call__)
  • Mocks created with a spec can now pass isinstance tests (__class__ returns the type of the spec)
  • Default numeric value for MagicMock is 1 rather than zero (because the MagicMock bool defaults to True and 0 is False)
  • Improved failure message for assert_called_with() when the mock has not been called at all
  • Adding the following to the set of supported magic methods:
    • __getformat__ and __setformat__
    • pickle methods
    • __trunc__, __ceil__ and __floor__
    • __sizeof__
  • Added ‘build_sphinx’ command to setup.py (requires setuptools or distribute) Thanks to Florian Bauer
  • with statement tests now skipped on Python 2.4
  • Tests require unittest2 to run on Python 2.7
  • Improved several docstrings and documentation

2010/06/23 Version 0.7.0 beta 2

  • patch.dict() works as a context manager as well as a decorator
  • patch.dict takes a string to specify dictionary as well as a dictionary object. If a string is supplied the name specified is imported
  • BUGFIX: patch.dict restores dictionary even when an exception is raised

2010/06/22 Version 0.7.0 beta 1

  • Addition of mocksignature()
  • Ability to mock magic methods
  • Ability to use patch and patch.object as class decorators
  • Renamed patch_object to patch.object() (patch_object is deprecated)
  • Addition of MagicMock class with all magic methods pre-created for you
  • Python 3 compatibility (tested with 3.2 but should work with 3.0 & 3.1 as well)
  • Addition of patch.dict() for changing dictionaries during a test
  • Addition of mocksignature argument to patch and patch.object
  • help(mock) works now (on the module). Can no longer use __bases__ as a valid sentinel name (thanks to Stephen Emslie for reporting and diagnosing this)
  • Addition of soft comparisons: call_args, call_args_list and method_calls now return tuple-like objects which compare equal even when empty args or kwargs are skipped
  • Added docstrings.
  • BUGFIX: side_effect now works with BaseException exceptions like KeyboardInterrupt
  • BUGFIX: patching the same object twice now restores the patches correctly
  • The tests now require unittest2 to run
  • Konrad Delong added as co-maintainer

2009/08/22 Version 0.6.0

  • New test layout compatible with test discovery
  • Descriptors (static methods / class methods etc) can now be patched and restored correctly
  • Mocks can raise exceptions when called by setting side_effect to an exception class or instance
  • Mocks that wrap objects will not pass on calls to the underlying object if an explicit return_value is set

2009/04/17 Version 0.5.0

  • Made DEFAULT part of the public api.
  • Documentation built with Sphinx.
  • side_effect is now called with the same arguments as the mock is called with and if returns a non-DEFAULT value that is automatically set as the mock.return_value.
  • wraps keyword argument used for wrapping objects (and passing calls through to the wrapped object).
  • Mock.reset renamed to Mock.reset_mock, as reset is a common API name.
  • patch / patch_object are now context managers and can be used with with.
  • A new ‘create’ keyword argument to patch and patch_object that allows them to patch (and unpatch) attributes that don’t exist. (Potentially unsafe to use - it can allow you to have tests that pass when they are testing an API that doesn’t exist - use at your own risk!)
  • The methods keyword argument to Mock has been removed and merged with spec. The spec argument can now be a list of methods or an object to take the spec from.
  • Nested patches may now be applied in a different order (created mocks passed in the opposite order). This is actually a bugfix.
  • patch and patch_object now take a spec keyword argument. If spec is passed in as ‘True’ then the Mock created will take the object it is replacing as its spec object. If the object being replaced is a class, then the return value for the mock will also use the class as a spec.
  • A Mock created without a spec will not attempt to mock any magic methods / attributes (they will raise an AttributeError instead).

2008/10/12 Version 0.4.0

  • Default return value is now a new mock rather than None

  • return_value added as a keyword argument to the constructor

  • New method ‘assert_called_with’

  • Added ‘side_effect’ attribute / keyword argument called when mock is called

  • patch decorator split into two decorators:

    • patch_object which takes an object and an attribute name to patch (plus optionally a value to patch with which defaults to a mock object)
    • patch which takes a string specifying a target to patch; in the form ‘package.module.Class.attribute’. (plus optionally a value to patch with which defaults to a mock object)
  • Can now patch objects with None

  • Change to patch for nose compatibility with error reporting in wrapped functions

  • Reset no longer clears children / return value etc - it just resets call count and call args. It also calls reset on all children (and the return value if it is a mock).

Thanks to Konrad Delong, Kevin Dangoor and others for patches and suggestions.

2007/12/03 Version 0.3.1

patch maintains the name of decorated functions for compatibility with nose test autodiscovery.

Tests decorated with patch that use the two argument form (implicit mock creation) will receive the mock(s) passed in as extra arguments.

Thanks to Kevin Dangoor for these changes.

2007/11/30 Version 0.3.0

Removed patch_module. patch can now take a string as the first argument for patching modules.

The third argument to patch is optional - a mock will be created by default if it is not passed in.

2007/11/21 Version 0.2.1

Bug fix, allows reuse of functions decorated with patch and patch_module.

2007/11/20 Version 0.2.0

Added spec keyword argument for creating Mock objects from a specification object.

Added patch and patch_module monkey patching decorators.

Added sentinel for convenient access to unique objects.

Distribution includes unit tests.

2007/11/19 Version 0.1.0

Initial release.

TODO and Limitations

Contributions, bug reports and comments welcomed!

Feature requests and bug reports are handled on the issue tracker:

wraps is not integrated with magic methods.

patch could auto-do the patching in the constructor and unpatch in the destructor. This would be useful in itself, but violates TOOWTDI and would be unsafe for IronPython & PyPy (non-deterministic calling of destructors). Destructors aren’t called in CPython where there are cycles, but a weak reference with a callback can be used to get round this.

Mock has several attributes. This makes it unsuitable for mocking objects that use these attribute names. A way round this would be to provide methods that hide these attributes when needed. In 0.8 many, but not all, of these attributes are renamed to gain a _mock prefix, making it less likely that they will clash. Any outstanding attributes that haven’t been modified with the prefix should be changed.

If a patch is started using patch.start and then not stopped correctly then the unpatching is not done. Using weak references it would be possible to detect and fix this when the patch object itself is garbage collected. This would be tricky to get right though.

When a Mock is created by patch, arbitrary keywords can be used to set attributes. If patch is created with a spec, and is replacing a class, then a return_value mock is created. The keyword arguments are not applied to the child mock, but could be.

When mocking a class with patch, passing in spec=True or autospec=True, the mock class has an instance created from the same spec. Should this be the default behaviour for mocks anyway (mock return values inheriting the spec from their parent), or should it be controlled by an additional keyword argument (inherit) to the Mock constructor? create_autospec does this, so an additional keyword argument to Mock is probably unnecessary.

The mocksignature argument to patch with a non Mock passed into new_callable will probably cause an error. Should it just be invalid?

Note that NonCallableMock and NonCallableMagicMock still have the unused (and unusable) attributes: return_value, side_effect, call_count, call_args and call_args_list. These could be removed or raise errors on getting / setting. They also have the assert_called_with and assert_called_once_with methods. Removing these would be pointless as fetching them would create a mock (attribute) that could be called without error.

Some outstanding technical debt. The way autospeccing mocks function signatures was copied and modified from mocksignature. This could all be refactored into one set of functions instead of two. The way we tell if patchers are started and if a patcher is being used for a patch.multiple call are both horrible. There are now a host of helper functions that should be rationalised. (Probably time to split mock into a package instead of a module.)

Passing arbitrary keyword arguments to create_autospec, or patch with autospec, when mocking a function works fine. However, the arbitrary attributes are set on the created mock - but create_autospec returns a real function (which doesn’t have those attributes). However, what is the use case for using autospec to create functions with attributes that don’t exist on the original?

mocksignature, plus the call_args_list and method_calls attributes of Mock could all be deprecated.