Monday 16 December 2013

Pairwise testing


Problem: Test cases covering multiple variables can be tricky to create
Lately we have been testing workflow rules. This calls for test cases that covers many variables, and as the number of variable goes up, so does complexity. We started the test specification in front of a decision tree, and quickly realized that writing the cases manually was too time-consuming, not to mention risky as the number of combinations was too much for us to cope with.

Solution: Apply all-pairs testing for the test case creation, and a tool to do the pairing.

There are many tools for creating the test cases, and the place to visit is www.pairwise.org Here you will find a tool that does the job, no matter if you prefer command prompt, text driven or GUI driven tools that can create nice graphical models of the test.

I like it simple, so I used PICT, a command prompt driven tool that takes text files as input and delivers text files as out put. Easy-peasy, just put your variables in a file, and transform that into a list of test cases that you can use for your test. For more information on PICT I suggest that you read the help-file found here: http://www.amibugshare.com/pict/help.html

Many of our test cases are parameter driven in MS test manager, meaning that it is possible to copy the result from the result file directly into the parameters into the test case. The only precondition is that you make sure that the columns in the result are in the same order as the parameters in MS test manager.

Consider the technique and tools for input test scenarios.

Happy testing !

/Nicolai

1 comment:

  1. I found this very comprehensive post on the subject on Jeff's blog:
    http://testerstories.com/combination-testing-making-it-manageable/

    Worth a moment of your time if you are studying the subject.

    Happy testing!

    /Nicolai

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