Mock - Mocking and Testing Library

Author:Michael Foord Version:Mock 0.6.0 Date:2009/08/22 Homepage:Mock Homepage Documentation:PDF Documentation License:BSD License Support:Testing in Python Email List Contact:fuzzyman@voidspace.org.uk

Introduction

mock provides a core mock.Mock class that is intended to reduce the need to create a host of trivial stubs throughout your test suite. After performing an action, you can make assertions about which methods / attributes were used and arguments they were called with. You can also specify return values and set specific attributes in the normal way.

It also provides a mock.patch() decorator that handles patching module and class level attributes within the scope of a test, along with mock.sentinel for creating unique objects.

Most mocking libraries follow the ‘record -> replay’ pattern of mocking. Mock uses the ‘action -> assertion’ pattern, which is more readable and intuitive; particularly when working with the Python unittest module. For a discussion of the merits of the two approaches, see Mocking, Patching, Stubbing: all that Stuff.

Downloading

The current version is 0.6.0, dated 23rd August 2009. Mock is still experimental; the API may change. If you find bugs or have suggestions for improvements / extensions then please email me.

• mock.py (module only)
• mock-0.6.0.zip (module, tests and documentation)
• mock documentation as PDF
• Google Code Home & Subversion Repository

You can checkout the latest development version from the Google Code Subversion repository with the following command:

svn checkout http://mock.googlecode.com/svn/trunk/ mock-read-only

Mock is registered with PyPi (Mock on PyPi). If you have pip, setuptools or Distribute you can install mock with:

easy_install mock

pip mock

API Documentation

• The Mock Class
  • Methods
  • Calling
  • Attributes
• Patch Decorators
  • patch
  • patch_object
  • Nesting Patch Decorators
  • Patching Descriptors
• Sentinel
  • Sentinel Example

User Guide

• Getting Started with Mock
  • Using Mock
  • Sentinel
  • Patch Decorators
• Examples
  • Mock Examples
  • Patch Decorator Examples
• TODO and Limitations
• CHANGELOG
  • 2009/08/22 Version 0.6.0
  • 2009/04/17 Version 0.5.0
  • 2008/10/12 Version 0.4.0
  • 2007/12/03 Version 0.3.1
  • 2007/11/30 Version 0.3.0
  • 2007/11/21 Version 0.2.1
  • 2007/11/20 Version 0.2.0
  • 2007/11/19 Version 0.1.0

References

Articles and blog entries on testing with Mock:

• Python mock testing techniques and tools
• How To Test Django Template Tags
• A presentation on Unit Testing with Mock
• Mocking with Django and Google AppEngine

Tests

Mock uses the discover module to collect and run its tests. discover.py is included in the subversion repository so from a fresh checkout you can execute the following to run all the tests:

python discover.py

On Python 2.4 you will see one failure - testwith.py will fail to import as it uses the with statement which is invalid syntax under Python 2.4.