Automatic generation of test sequences form EFSM models using evolutionary algorithms

Automated test data generation through evolutionary testing (ET) is a topic of interest to the software engineering community. While there are many ET-based techniques for automatically generating test data from code, the problem of generating test data from an extended finite state machine (EFSMs) is more complex and has received little attention. In this paper, we introduce a novel approach that addresses the problem of generating input test sequences that trigger given feasible paths in an EFSM model by employing an ET-based technique. The proposed approach expresses the problem as a search for input parameters to be applied to a set of functions to be called sequentially. In order to apply ET-based technique, a new fitness function is introduced to cope with the case when a test target involves calls to a set of transitions sequentially. We evaluate our approach empirically using five sets of randomly generated paths through two EFSM case studies: INRES and class 2 transport protocols. In the experiments, we apply two search techniques: a random and an ET-based which utilizes our new fitness function. Experimental results show that the proposed approach produces input test sequences that trigger all the feasible paths used with a success rate of 100%, however, the random technique failed in most cases with a success rate of 20.8%

A search-based technique for testing from extended finite state machine model

Extended finite state machines (EFSMs), and languages such as state-charts that are similar to EFSMs, are widely used to model state-based systems. When testing from an EFSM M it is common to aim to produce a set of test sequences (input sequences) that satisfies a test criterion that relates to the transition paths (TPs) of M that are executed by the test sequences. For example, we might require that the set of TPs triggered includes all of the transitions of M. One approach to generating such a set of test sequences is to split the problem into two stages: choosing a set of TPs that achieves the test criterion and then producing test sequences to trigger these TPs. However, the EFSM may contain infeasible TPs and the problem of generating a test sequence to trigger a given feasible TP (FTP) is generally uncomputable. In this paper we present a search-based approach that uses two techniques: (1) A TP fitness metric based on our previous work that estimates the feasibility of a given transition path; and (2) A fitness function to guide the search for a test sequence to trigger a given FTP. We evaluated our approach on five EFSMs: A simple in-flight safety system; a class II transport protocol; a lift system; an ATM; and the Inres initiator. In the experiments the proposed approach successfully tested approximately 96.75 % of the transitions and the proposed test sequence generation technique triggered all of the generated FTPs

Testing in context: Efficiency and executability

Testing each software component in isolation is not always feasible. We consider testing a deterministic Implementation Under Test (IUT) together with some other correctly implemented components as its context. One of the essential issues of testing in context is test executability problem, i.e., tests generated solely from the specification of the IUT may not be executable due to the uncontrollable interaction between the IUT and its context. On the other hand, generating a test sequence from the abstract specifications of a stateful IUT and its context often suffers from the well-known state explosion problem. In this dissertation, we solve the problem of generating a minimal-length test sequence from a given specification of a stateful IUT and its embedded context. By adopting model checking techniques, we avoid the state explosion problem during test generation and avoid the test executability problem during testing in context

Separating sequence overlap for automated test sequence generation

Finite state machines have been used to model a number of classes of system and there has thus been much interest in the automatic generation of test sequences from finite state machines. Many finite state machine based test techniques utilize sequences that check the final states of transitions, the most general such sequence being a separating sequence: an input sequence that distinguishes between two states of an FSM. When using such techniques the test sequence length can be reduced by utilizing overlap. This paper investigates overlap for separating sequences and shows how this can be incorporated into test sequence generation