Lambda expressions have been introduced in Java 8 to support functional programming and enable behavior parameterization by passing functions as parameters to methods. The majority of software clones (duplicated code) are known to have behavioral differences (i.e., Type-2 and Type-3 clones). However, to the best of our knowledge, there is no previous work to investigate the utility of Lambda expressions for parameterizing such behavioral differences in clones. In this paper, we propose a technique that examines the applicability of Lambda expressions for the refactoring of clones with behavioral differences. Moreover, we empirically investigate the applicability and characteristics of the Lambda expressions introduced to refactor a large dataset of clones. Our findings show that Lambda expressions enable the refactoring of a significant portion of clones that could not be refactored by any other means.

Prior to the recent updates of the JavaScript language specifications, developers had to use custom solutions to emulate constructs such as classes, modules, and namespaces in JavaScript programs. This paper introduces JSDEODORANT, an automatic approach for detecting function constructors declared locally, under a namespace, or even in other modules. The comparison with the state-of-the-art tool, JSClassFinder, shows that while the precision of the tools is very similar (97% and 98%), the recall of JSDEODORANT (98%) is much higher than JSClassFinder (61%).