Platform for test doubles in Python (mocks, stubs, and dummies)
Ludibrio is registered with PyPi. If you have pip, setuptools or Distribute you can install mock with:
$ sudo easy_install ludibrio
The latest official version is 3.0.2. Here’s how to get it:
See the http://ludibriar.appspot.com/ for the current documentation.
Ludibrio’s development may be viewed and followed on github:
Retrieve the source code using ‘git’:
$ git clone git://github.com/nsigustavo/ludibrio.git
Install package in ‘development mode’ and run tests with doctestcommand:
$ sudo easy_install doctestcommand $ git clone git://github.com/nsigustavo/ludibrio.git $ cd ludibrio $ sudo python setup.py develop $ cd ludibrio $ doctest
Test doubles are fake objects that simulate the behavior of a real object for testing purposes.
Mocks are objects pre-programmed with expectations which form a specification of the calls they are expected to receive:
>>> from ludibrio import Mock >>> with Mock() as MySQLdb: ... con = MySQLdb.connect('server', 'user', 'XXXX') ... con.select_db('DB') >> None ... cursor = con.cursor() ... cursor.execute('select * from numbers') >> None ... cursor.fetchall() >> [1,2,3,4,5]
>>> con = MySQLdb.connect('server', 'user', 'XXXX') >>> con.select_db('DB') >>> cursor = con.cursor() >>> cursor.execute('select * from numbers') >>> cursor.fetchall() [1, 2, 3, 4, 5] >>> MySQLdb.validate() #passed
Stubs provide pre-defined answers to method calls made during a test:
>>> from ludibrio import Stub >>> with Stub() as x: ... x.anything() >> 'response'
>>> x.anything() 'response'
Ludibrio also offers a replace mode, which basically means if a “from … import …” statement is defined into a ‘with’ scope, the replay mechanism will return a mock object to replace the original object in namespace of the whole Python interpreter (including any modules, etc). There’s a simple example below to illustrate how use it:
>>> from ludibrio import Stub >>> with Stub() as time: ... from time import time ... time() >> 171
>>> from time import time >>> time() 171
Two Ludibrio’s powerful features that aren’t found in other mocking systems is the ability of proxying existing objects, or patching a real instance or class.
When an object is proxied, Ludibrio create a Test Double object holding a reference to the real object, allowing expressions passthrough to it(mocked or not, and by default or on request):
>>> from os.path import splitext >>> with Stub(proxy=splitext) as splitext: ... splitext('ludibrio/stubed.py') >> ('/temp/temp','.temp')
>>> splitext('mock.py') ('mock', '.py') >>> splitext('ludibrio/stubed.py') ('/temp/temp', '.temp')