The Scent of a Smell: A Comparison Between Structural and Textual Code Smells

Code smells are symptoms of poor design and implementation choices. Several studies demonstrate their negative
effects on maintenance cost. Despite this, developers tend
to not refactor code smells. Almost all the current code smell
detectors and refactoring tools are based on structural information. In this paper, we conjecture that textual information, as opposed to structural information, is better aligned
with developers’ perception of code smells. In this paper,
we systematically investigate how textually or structurally
detected code smells are treated and perceived by developers. To this aim, we first conduct a mining study to obtain a
quantitative perspective. Secondly, we conduct an industrial
user study with 5 quality experts in order to qualitatively
analyze how developers perceive code smells identified using
different sources of information and whether textually or
structurally detected code smells are easier to refactor. Results clearly indicate that textually detected smells are easier
to perceive and subject to more refactoring operations.