We all love refactoring, but? How and why do developers apply refactorings in practice? Istvan introduces a dataset with refactorings, for everyone to use, yeah!
The data has 37 releases of 7 open source Java systems, refactorings, source code metrics and maintainability information on class and method level. The dataset is available.
He uses it to answer the following questions.
R1 Maintainability of refactored classes.
Result: Classes with poor maintainability are subject to more refactorings.
R2 The effect of refactorings on source code metrics
Result: Refactorings decreased: coupling, size complexity, clones, total lines of code.