Co-Occurrence of Design Patterns and Bad Smells in Software Systems: An Exploratory Study

Abstract

A design pattern is a general reusable solution to a recurring problem in software design. Bad smells are symptoms that may indicate something wrong in the system design or code. Therefore, design patterns and bad smells represent antagonistic structures. They are subject of recurring research and typically appear in software systems. Although design patterns represent good design, their use is often inadequate because their implementation is not always trivial or they may be unnecessarily employed. The inadequate use of design patterns may lead to a bad smell. Therefore, this paper performs an exploratory study in order to identify instances of co-occurrences of design patterns and bad smells. This study is performed over five systems and discovers some co-occurrences between design patterns and bad smells. For instance, we observed the co-occurrences of Command with God Class and Template Method with Duplicated Code. The results of this study make it possible to understand in which situations design patterns are misused or overused and establish guidelines for their better use.

An exploratory study on cooccurrence of design patterns and bad smells using software metrics

“…We chose them because they are problematic for software maintenance and they are related to data problems, a large amount of information, complexity, and coupling. Moreover, previous studies [10][11][12][13] have used them to investigate their impact on the emergence of software faults and have analyzed the static relationships between them and design patterns. One way to detect bad smells is done by using detection strategies.…”

“…We based our analysis on the conviction metric because it measures how important and accurate one given rule is in a data set. Moreover, this metric has been used by previous studies 11,13 to evaluate cooccurrences between design patterns and bad smells.…”

“…[5][6][7][8][9] However, design patterns may also introduce complex structures in the source code, such as the bad smells occurrences, when they are not correctly applied. [10][11][12][13][14] Previously, we carried out systematic literature mapping, and we concluded that these two structures have been studied under three aspects: impact on software quality, refactoring, and cooccurrences. 15 Moreover, we also found that, although there are papers associating design pattern with bad smells, [10][11][12][13] this topic is still little explored and there are some gaps not covered by the studies done, such as situations that culminate in the cooccurrence between design patterns and bad smells and situations in which design patterns are more likely to cooccur with bad smells.…”

“…[10][11][12][13][14] Previously, we carried out systematic literature mapping, and we concluded that these two structures have been studied under three aspects: impact on software quality, refactoring, and cooccurrences. 15 Moreover, we also found that, although there are papers associating design pattern with bad smells, [10][11][12][13] this topic is still little explored and there are some gaps not covered by the studies done, such as situations that culminate in the cooccurrence between design patterns and bad smells and situations in which design patterns are more likely to cooccur with bad smells. Therefore, an investigation about these subjects may serve to alert researchers and developers that the application of design patterns may result in problematic structures that increase the complexity, readability, and comprehension of a software system.…”

Evaluating Co-Occurrence of GOF Design Patterns with God Class and Long Method Bad Smells

“…Design patterns may be used to remove bad smells. On the other hand, there are studies that identify co-occurrence of design patterns and bad smells [3,10,11,18]. Although design patterns are intended to improve software quality, they do not necessarily avoid bad smells.…”