On Sat, 23 May 2009 06:00:15 -0700, pigmartian wrote: > Hi, > > I'm working on a unit test framework for a module. The module I'm > testing indirectly calls another module which is expensive to access --- > CDLLs whose functions access a database. ... > The examples I can find of creating and using Mock or Stub objects seem > to all follow a pattern where the fake objects are passed in as > arguments to the code being tested. For example, see the "Example > Usage" section here: http://python-mock.sourceforge.net. But that > doesn't work in my case as the module I'm testing doesn't directly use > the module that I want to replace. > > Can anybody suggest something?
Sounds like a job for monkey-patching! Currently, you have this: # inside test_MyModule: import MyModule test_code() # inside MyModule: import IntermediateModule # inside IntermediateModule: import ExpensiveModule You want to leave MyModule and IntermediateModule as they are, but replace ExpensiveModule with MockExpensiveModule. Try this: # inside test_MyModule: import MyModule import MockExpensiveModule MyModule.IntermediateModule.ExpensiveModule = MockExpensiveModule test_code() That should work, unless IntermediateModule uses "from ExpensiveModule import functions" instead of "import ExpensiveModule". In that case, you will have to monkey-patch each individual object rather than the entire module: MyModule.IntermediateModule.afunc = MockExpensiveModule.afunc MyModule.IntermediateModule.bfunc = MockExpensiveModule.bfunc MyModule.IntermediateModule.cfunc = MockExpensiveModule.cfunc # etc... -- Steven -- http://mail.python.org/mailman/listinfo/python-list
