Evaluating Maintainability Prejudices with a Large-Scale Study of Open-Source Projects

Exaggeration or context changes can render maintainability experience into prejudice. For example, JavaScript is often seen as least elegant language and hence of lowest maintainability. Such prejudice should not guide decisions without prior empirical validation. We formulated 10 hypotheses about maintainability based on prejudices and test them in a large set of open-source projects (6,897 GitHub repositories, 402 million lines, 5 programming languages). We operationalize maintainability with five static analysis metrics. We found that JavaScript code is not worse than other code, Java code shows higher maintainability than C# code and C code has longer methods than other code. The quality of interface documentation is better in Java code than in other code. Code developed by teams is not of higher and large code bases not of lower maintainability. Projects with high maintainability are not more popular or more often forked. Overall, most hypotheses are not supported by open-source data.Comment: 20 page

Using Static Analysis and Static Measurement for Industrial Software Quality Evaluation

Business organizations that outsource software development need to evaluate the quality of the code delivered by suppliers. In this paper, we illustrate an experience in setting up and using a toolset for evaluating code quality for a company that outsources software development. The selected tools perform static code analysis and static measurement, and provide evidence of possible quality issues. To verify whether the issues reported by tools are associated to real problems, code inspections were carried out. The combination of automated analysis and inspections proved effective, in that several types of defects were identified. Based on our findings, the business company was able to learn what are the most frequent and dangerous types of defects that affect the acquired code: this knowledge is now being used on a regular basis to perform focused verification activities