Hello Roberto and Thierry,
as I promised, I am sending you a proof-of-concept code that demonstrates, how
we can mock DS in unit tests for library function (see attachment). You can run
tests just by executing py.test in tests directory.
Only 3 files are of interest here:
lib389/dsmodules/repl.py - this is a Python module with functions - they expect
DS instance as the first argument. Since they are functions, not methods, I can
just mock DS and pass that fake one as the first argument to them in unit tests.
tests/test_dsmodules/conftest.py - this file contains definition of mock DS
class along with py.test fixture, that returns it.
tests/test_dsmodules/test_repl.py - this contains unit tests for functions from
What I do is quite simple - I override ldapadd, ldapdelete .. methods of mock DS
class, so that instead of sending command to real DS instance, they just store
the data in 'dit' dictionary (which represents content stored in DS). This way,
I can check that when I call e.g. function enable_changelog(..), in the end DS
will have correct changelog entry.
To put it very bluntly - enable_changelog(..) function just adds correct
changelog entry to whatever is passed to it as the first argument. In unit
tests, it is mock DS, otherwise it would be real DS class that sends real ldap
commands to real DS instance behind.
Now I can successfully test that enable_changelog really works, without going
into trouble defining DSInstance or ldap calls at all. Also, I believe this
approach would work for 95% of all functions in lib389. Another benefit is that
unit tests are much faster, than on real DS instance.
Sidenote: even though everything is defined in separate namespace of 'repl'
module as function, in runtime they can be used as normal methods of class
DSInstance. That is handled by DSModuleProxy. We already went through this, but
not with Roberto.
Hopefully, now with some code in our hands, we will be able to understand each
other on this 'mocking' issue and come to conclusions more quickly.
Let me know what you think.