surrogate is a micro-lib helping people to create stubs
for non-existing modules in sys.modules so that later
those modules can be imported. surrogate does not touch
modules that exist in sys.modules even if you ask it to.
At the moment surrogate offers only decorator interface
but it is planned to add context-manager interface as well.
This library has been forked from Kostia Balytskyi's ikostia/surrogate for packaging and posting to PyPi. The commit history remains intact, but I've broken the GitHub fork link to help make it clear to visitors from PyPi which repo corresponds to the packaged and published version.
Once author needed to write tests for a function that
works only in production (but not in developement env).
Those function imported modules that did not exist in
development environment. Thus, in order to test those
function, mocking of the aforementioned modules was
necessary. Unfortunately, author did not manage to
mock those modules with patch decorator from
mock library. It was necessary to create module stubs
first and then to mock them. This micro-lib does exactly
what author needed (except of the mistakes, of course).
Please, use surrogate as a function decorator
from surrogate import surrogate
@surrogate('sys.my.cool.module.stub1')
@surrogate('sys.my.cool.module.stub2')
def test_something():
from sys.my.cool.module import stub1
from sys.my.cool.module import stub2
import sys.my.cool as cool
import sys # this is a normal sys module
do_something()
Accourding to intention, you can use surrogate
with mock.patch decorators
from surrogate import surrogate
from mock import patch
@surrogate('this.module.doesnt.exist')
@patch('this.module.doesnt.exits', whatever)
def test_something():
from this.module.doesnt import exist
do_something()
This code can be used, distributed and modified in any ways one wants. If one gets any use of it author is already rewarded. On the other hand, do not expect any guaranteed support from author. Use it as is.