Code Smells in Elixir: Early Results from a Grey Literature Review

TL;DR

This study explores code smells in Elixir through a grey literature review, identifying traditional and new Elixir-specific smells, and highlights the need to enhance static analysis tools for better quality assurance.

Contribution

It provides the first catalog of Elixir-specific code smells and evaluates Credo’s detection capabilities, suggesting improvements for static analysis tools.

Findings

11 of 22 traditional code smells are discussed by Elixir developers

Only 2 traditional and 1 Elixir-specific smell are detected by Credo

Proposes 18 new Elixir-specific code smells

Abstract

Elixir is a new functional programming language whose popularity is rising in the industry. However, there are few works in the literature focused on studying the internal quality of systems implemented in this language. Particularly, to the best of our knowledge, there is currently no catalog of code smells for Elixir. Therefore, in this paper, through a grey literature review, we investigate whether Elixir developers discuss code smells. Our preliminary results indicate that 11 of the 22 traditional code smells cataloged by Fowler and Beck are discussed by Elixir developers. We also propose a list of 18 new smells specific for Elixir systems and investigate whether these smells are currently identified by Credo, a well-known static code analysis tool for Elixir. We conclude that only two traditional code smells and one Elixir-specific code smell are automatically detected by this tool. Thus, these early results represent an opportunity for extending tools such as Credo to detect code smells and then contribute to improving the internal quality of Elixir systems.