A Taxonomy of Testable HTML5 Canvas Issues

The HTML5 < canvas > is widely used to display high quality graphics in web applications. However, the combination of web, GUI, and visual techniques that are required to build < canvas > applications, together with the lack of testing and debugging tools, makes developing such applications very challenging. To help direct future research on testing < canvas > applications, in this paper we present a taxonomy of testable < canvas > issues. First, we extracted 2,403 < canvas >-related issue reports from 123 open-source GitHub projects that use the HTML5 < canvas >. Second, we constructed our taxonomy by manually classifying a random sample of 332 issue reports. Our manual classification identified five broad categories of testable < canvas > issues, such as Visual and Performance issues. We found that Visual issues are the most frequent (35%), while Performance issues are relatively infrequent (5%). We also found that many testable < canvas > issues that present themselves visually on the < canvas > are actually caused by other components of the web application. Our taxonomy of testable < canvas > issues can be used to steer future research into < canvas > issues and testing.