The PhD thesis "Code Smells and Refactorings for Elixir" is now publicly available

With great satisfaction, I announce that my PhD thesis, titled “Code Smells and Refactorings for Elixir,” is now publicly available! All the results and methodological details used in our research over the past three years can be openly accessed at:

Abstract:

Elixir is a modern functional programming language, created in 2012, whose popularity has been growing in the industry. Despite this fact, and to the best of our knowledge, there are few studies in the literature addressing the internal quality of systems implemented with this language. In particular, no study to date has investigated specific code smells or refactorings for Elixir. Therefore, to fill these research gaps, we take inspiration from Fowler’s well-known book on code smells and refactorings to prospect, study, document, and evaluate code smells and refactoring strategies specifically tailored to Elixir. In the first study, we employed a mixed-method approach to catalog 35 code smells, 23 of which are new and specific to Elixir, while 12 are traditional code smells cataloged by Fowler and Beck that also affect code implemented in this language. We validated this catalog by surveying 181 experienced Elixir developers from 37 countries across all continents. In a second study, we also adopted a mixed-method approach, including a systematic literature review, to catalog 82 refactoring strategies compatible with Elixir, 14 of which are novel and specific to this language. All these refactorings were validated through another survey answered by 151 developers from 42 countries. To document the cataloged code smells and refactorings, in addition to structured textual descriptions, we produced code examples representing them. Finally, we conducted a third study where the code smells and refactorings for Elixir were correlated, allowing the definition of practical guidelines on how each code smell can be removed systematically with the help of refactoring strategies. In this final study, we also cataloged five new composite refactorings for Elixir. Overall, the results of this thesis have practical implications for the prevention and removal of code smells in Elixir, as well as the prioritization of understanding and using refactoring strategies for this language.

Enjoy!