Program Flow Analysis for Reducing and Estimating the Cost of Test Coverage Criteria

Testing a software system consists of executing it over a suitable sample of input data and then checking if the output produced matches what was expected. Testing is widely used to enhance software quality, and, specifically, to uncover bugs that are inevitably introduced during the software development process. One of the most difficult problems in testing is knowing when to stop the testing process. On the one hand, it is not possible in general to give an answer to whether a test suite guarantees the absence of faults. On the other hand, we need a way to limit the cost of testing. Therefore, it is useful to have criteria to determine when a program has been tested enough. Ideally, the testing process should be planned in advance. However, in practice the tests are incorporated little by little, until some adequacy criterion is satisfied. In particular, different coverages can be used to determine when the program has been tested enough. The idea is to guarantee that each statement, decision or other feature of the program has been executed at least once under some test. A major problem is that testing takes a considerable amount of the time and resources spent on producing software [?]. Therefore, it would be useful to have ways 1. to reduce the cost of testing, and 2. to estimate this cost. In particular, the number of tests to be executed impacts heavily on the cost of testing. In fact, the time and resources needed for testing increase as the number of test cases increases. Hence, to reduce the cost of testing, the number of test cases generated to satisfy a selected test criterion should be as small as possible. Moreover, a bound on the number of tests that have to be performed to satisfy a selected test strategy can be used by managers and testers to estimate the effort needed to carry out the tests.Sociedad Argentina de Informática e Investigación Operativ

Structural Testing of Active DataBases

Active databases (ADBs) are databases that include active components or agents that can execute actions. The rise of active databases in the picture of software development has a great impact on software systems and in the discipline of software engineering. However, we still lack the foundations that are needed to adequately support this new tool. These foundations are needed in order to properly apply known software engineering techniques to ADBs and systems that use them. Among the methods and techniques used to improve quality, we count systematic testing. In this work, we generalize structural testing techniques to ADB systems. We introduce a model of active databases, called dbgraph, suitable for testing. We show that dbgraphs can be used to generalize structural testing techniques for ADBs. Moreover, we introduce several new structural criteria aimed at find errors in a set of rules for an ADB. We also compare the strength of the coverage criteria presented in this work.Supported in part by UBACyT grant EX186.Sociedad Argentina de Informática e Investigación Operativ

Using spanning sets for coverage testing

Abstract—A test coverage criterion defines a set Ec of entities of the program flowgraph and requires that every entity in this set is covered under some test case. Coverage criteria are also used to measure the adequacy of the executed test cases. In this paper, we introduce the notion of spanning sets of entities for coverage testing. A spanning set is a minimum subset of Ec, such that a test suite covering the entities in this subset is guaranteed to cover every entity in Ec. When the coverage of an entity always guarantees the coverage of another entity, the former is said to subsume the latter. Based on the subsumption relation between entities, we provide a generic algorithm to find spanning sets for control flow and data flow-based test coverage criteria. We suggest several useful applications of spanning sets: They help reduce and estimate the number of test cases needed to satisfy coverage criteria. We also empirically investigate how the use of spanning sets affects the fault detection effectiveness. Index Terms—Control flow, coverage criteria, data flow, ddgraph, spanning sets, subsumption.