  Software testing is a critical activity to ensure that software complies with
its specification. However, current software testing activities tend not to be
completely effective when applied in specific software domains in Virtual
Reality (VR) that has several new types of features such as images, sounds,
videos, and differentiated interaction, which can become sources of new kinds
of faults. This paper presents an overview of the main VR characteristics that
can have an impact on verification, validation, and testing (VV&T).
Furthermore, it analyzes some of the most successful VR open-source projects to
draw a picture concerning the danger of the lack of software testing
activities. We compared the current state of software testing practice in
open-source VR projects and evaluate how the lack of testing can be damaging to
the development of a product. We assessed the incidence of code smells and
verified how such projects behave concerning the tendency to present faults.
The results showed that the practice of software testing is not yet widespread
in the development of VR applications. It was also found that there is a high
incidence of code smells in VR projects. Regarding fault-proneness the results
showed that about 12.2% of the classes analyzed in VR projects are fault-prone.
Regarding the application of software testing techniques on VR projects, it was
observed that only a small number of projects are concerned about developing
test cases for VR projects, perhaps because we still do not have the necessary
tools to help in this direction. Concerning smells, we concluded that there is
a high incidence in VR projects, especially regarding implementing smells and
this high incidence can have a significant influence on faults. Finally, the
study related to fault proneness pointed out that the lack of software testing
activity is a significant risk to the success of the projects.
