Sniffing Through Millions of Blocks for Bad Smells

Abstract

Code smells codify poor coding patterns known to degrade software quality. Block-based languages have proven to be a viable educational and end-user programming paradigm with increasing adoption across a broad spectrum of users and domains. This rising popularity of this programming paradigm calls for a serious look at the program quality written in block-based languages. While code smells in the context of text-based languages have been studied extensively, the research community lacks a comprehensive understanding of code smells in block-based software. To address this problem, we present the results of a largescale study of code smells prevalent in programs written in the highly popular Scratch programming language. We analyzed programs submitted to the public Scratch repository in 2016, considering a million programs altogether. We discovered interesting relationships between the prevalence of certain smells and the levels of proficiency of the programmers commonly introducing them. Our findings not only can help block-based programmers improve the quality of their software, but also establish the requirements for refactoring support in this programming domain.

Analysing Students’ Scratch Programs and Addressing Issues using Elementary Patterns

“…For example, only 7.48% of projects used 5 or more variables; 78% of projects had a cyclomatic complexity of 1 (which means no control or decision points), and 13.08% of projects had a cyclomatic complexity of 2 (exactly 1 decision point). Techapalokul [5] analyzed a million projects submitted to the Scratch public repository and came up with a number of bad smells in the code. Moreno and Robles [6] developed two plugins to automatically detect two bad programming habits they found to be regular with high school student' code.…”

“…Scratch should be used in the same way as other programming languages to teach good programming habits infused by solid teaching [7] Extremely Fine-Grained Programming This is when a program is constructed starting from a high level description and broken down to the primitives of the programming language. Novices also take the top-down approach to the extreme [5], [7]. Novices tend to break the problem into small pieces devoid of any logical coherency.…”

“…cat1, button2, etc. ), which makes the code unreadable and difficult to debug, makes objects in large programs extremely difficult to identify, and slows down the overall programming process [5], [6] Scratch doesn't enforce the deliberate naming of a new variable, and a name is assigned automatically. A change in this feature could improve the situation [5], [6] Code Repetition/ Duplicated Code…”

“…There is a large percentage of code cloning and duplicated code in the Scratch projects repository [4]- [6] Code repetition could be reduced by teaching abstraction and modularization [6] Unreachable Code/Dead Code A significant percentage of scripts contain dead code (uninvoked procedures, unmatched broadcast-receive messages, uninvoked code, empty event scripts, unused variables) [4], [5] Scratch programmers could benefit from: a separate workspace to store unused blocks, sharing projects, and sharing functionality (in the form of a library). This would help novices a great deal to get started [4].…”

Mensurando o desenvolvimento do Pensamento Computacional por meio de mapas auto-organizáveis: um estudo preliminar em uma Oficina de Jogos Digitais

“…A rubrica foi implementada em um sistema web denominado Dr. Scratch que se baseia em uma extensão do funcionamento do Hairball. A partir da análise automatizada de código tem sido possível obter resultados relacionados às boas e más práticas de programação utilizando Scratch (AIVALOGLOU; HERMANS, 2016;TECHAPALOKUL, 2017). No entanto, ainda não tem sido explorada em detalhes a evolução do código produzido por alunos e sua relação com a aquisição de competências do Pensamento Computacional.…”