In dynamic typing languages such as JavaScript, object types can be mutated easily such as by adding a field to an object. However, compiler optimizations rely on a fixed set of types, unintentional type mutations can invalidate the speculative code generated by the type-feedback JIT and deteriorate the quality of compiler optimizations. Since type mutations are invisible, finding and understan...

Nowadays, modern applications are developed using components written in different programming languages and technologies. The cost benefits of reuse the advantages each language two main incentives behind proliferation such systems. However, as number increases, so do challenges related to development maintenance these In situations, developers may introduce design smells (i.e., anti-patterns c...

It is a widely held belief that Free/Open Source Software (FOSS) development leads to the creation of software with the same, if not higher quality compared to that created using proprietary software development models. However there is little research on evaluating the quality of FOSS code, and the impact of project characteristics such as age, number of core developers, code-base size, etc. I...

The ubiquity of smartphones, and their very broad capabilities and usage, make the security of these devices tremendously important. Unfortunately, despite all progress in security and privacy mechanisms, vulnerabilities continue to proliferate. Research has shown that many vulnerabilities are due to insecure programming practices. However, each study has often dealt with a specific issue, maki...

Code critics are a recommendation facility of the Pharo Smalltalk IDE. They signal controversial implementation choices such as code smells at class and method level. They aim to promote the use of good and standard coding idioms for increased performance or a better use of object-oriented constructs. This paper studies relations among code critics by analyzing co-occurrences of code critics de...

In this paper, we argue that current research in aspect-oriented refactoring can benefit from specific efforts to develop a new coding style appropriate for aspect-orientation. This notion can be captured through catalogues of refactorings and code smells, after which it can provide a basis for tool developers. We successfully derived useful insights from the study of toy examples and think the...

A procedure’s client must satisfy its precondition— that is, reach a state in which the procedure may be called. Preconditions describe the state that needs to be reached, but not how to reach it. We use static analysis to infer the sequence of operations a variable goes through before being used as a parameter: “In parseProperties(String xml), the parameter xml normally stems from getPropertie...