DOM-based test adequacy criteria for web applications

To assess the quality of web application test cases, web developers currently measure code coverage. Although code coverage has traditionally been a popular test adequacy criterion, we believe it alone is not adequate for assessing the quality of web application test cases. We propose a set of novel DOM-based test adequacy criteria for web applications. These criteria aim at measuring coverage at two granularity levels, (1) the percentage of DOM states and transitions covered in the total state space of the web application under test, and (2) the percentage of elements covered in each particular DOM state. We present a technique and tool, called DomCovery, which automatically extracts and measures the proposed adequacy criteria and generates a visual DOM coverage report. Our evaluation shows that there is no correlation between code coverage and DOM coverage. A controlled experiment illustrates that participants using DomCovery completed coverage related tasks 22% more accurately and 66% faster.