Test suite prioritization by interaction coverage

Event-driven software (EDS) is a widely used class of software that takes sequences of events as input, changes state, and outputs new event sequences. Managing the size of tests suites for EDS is difficult as the number of event combinations and sequences grow exponentially with the number of events. We propose a new testing technique that extends software interaction testing. Traditional software interaction testing systematically examines all t-way interactions of parameters for a program. This paper extends the notion to t-way interactions over sequences of events. The technique applies to many classes of software; we focus on that of EDS. As a proof-of-concept, we prioritize existing test suites for four GUI-based programs by t-way interaction coverage. We compare the rate of fault detection with that of several other prioritization criteria. Results show that prioritization by interaction coverage has the fastest rate of fault detection in half of our experiments, making the most impact when tests have high interaction coverage.