Compreendendo programas por meio de Design by Contract: um estudo com desenvolvedores.

Abstract

Program comprehension is generally a difficult task, since each part of code meets specific requirements. In some cases, factors - such as comprehend programs that were written by others, limited scope of existing tools, and lack of documentation - add complexity. There fore, developers need an effective program comprehension approach that reduces maintenance costs and the risk of errors whether the program comprehension is incomplete. In order to mitigate that problem, systematic approaches are used, supported by tools, to verify comprehension using static (source code analysis) or dynamic (data on execution). Dynamic approaches are used because of their effectiveness, since they simply run a test to see the result, however, they fail to use high-level behavioral information that can be verified. Still, this information can be captured while defining contracts, for example in the Design by Contract methodology. Nevertheless, for the best of our knowledge, there is no systematic approach to program comprehension that uses contracts. In this work, we propose a study to program comprehension supported by a systematized approach, in order to prioritize the writing of contracts in C# programs using the principles of Design by Contract through the Code Contracts library. It can still be used in any programming language that supports Design by Contract. We evaluated it in software development environments with 12 developers of a research and development center in computer science, considering the approach application to three methods (routines) of an open-source project. The results of our study indicate better comprehension of methods using contracts, and, on the other hand, favoring the writing of contracts in methods, initially unknown to developers.