APPLYING CONVENTIONAL UNIT TESTING TECHNIQUES TO ABSTRACT DATA TYPE OPERATIONS

Abstract

Abstract data types (ADTs) represent the fundamental building blocks of object-oriented software development. There have been a variety of techniques in the literature for testing ADT modules. Virtually all of the proposed techniques have involved testing sequences of ADT operations (e.g., for a stack ADT, test the sequence PUSH; PUSH; POP) to discover defects in their interactions. However, the operations inside an ADT module are really nothing more than conventional procedures and functions. Consequently, it is conceivable that conventional subprogram unit testing techniques can be adapted to test ADT operations. To support such testing techniques, test cases are best designed and expressed in terms of data values. When test cases are integers, for example, expressing a test case is trivial (e.g., ‘253’). However, when test cases are data abstractions (such as stacks), this problem is much more difficult due to the variety of different formats in which a single data abstraction can be legitimately viewed. In this paper, we provide a conceptual framework for applying classical white-box and black-box unit testing techniques to ADT operations. We then use this framework to develop a collection of guidelines for determining the best format for test case design, given different module characteristics and testing techniques.