Question

I am looking to automatically generate unit tests in MonoDevelop/.Net.

I’ve tried NUnit, but it doesn’t generate the tests. In eclipse, the plug-in randoop does this, however it targets Java and JUnit.

How can I automatically generate unit tests in MonoDevelop and/or for .Net? Or perhaps there is an existing tool out there I am unaware of…

Answer 1

Calling methods with different (random) input is just one part of the process. You also need to define the correct result for each input, and I don’t think a tool can do that for you.

randoop only seems to check very few very basic properties of equal, which is not of great use imo and also might lead to a false impression of correctness (“Hey look, all tests pass, my software is ok” …)

Also just randomly generating code (and input) has the risk of undetermined test results. You might or might not get tests that really find flaws in your code.

That said, a quick googling gave the following starting points for approaches you might want to take:

• You might be interested in using test case generators (this CodeProject article describes a very simple one). They support you in generating the “boilerplate” code and can make sure, you dont miss any classes/methods you want to test. Of course, the generated tests need to be adapted by defining proper (i.e. meaningful) input and (correct) output values. Googling for “NUnit Test generators” will give you other links, also for commercial software, which i don’t want to repeat here …
• NUnit (and other testing frameworks) support parameterized tests: These can be used to test a whole class of input scenarios. For NUnit, i found the Random attribute which lets you generate random input (in a certain range) for your methods. Remember what I wrote above about random test inputs: the results of these tests will not be reproducable which renders them useless for automatic or regression testing.

That said, also look at this question (and certainly others on SO), which may support my argument against automatic unit test generation.