Coverage at a Crossroads

Coverage.py is undergoing changes to reduce execution-time overhead by leveraging new Python features. The current method involves a trace function for each line of Python execution, leading to inefficiencies for statement coverage. SlipCover offers a low-overhead alternative by directly tracking code execution without a trace function. Python 3.12 introduced sys.monitoring for event-based line execution tracking, reducing overhead for line coverage but posing challenges for branch coverage due to event handling limitations. SlipCover's approach of using line events for branch coverage presents a promising solution, although it requires adjustments in data collection and analysis. Coverage.py is exploring ways to adapt SlipCover's techniques while addressing issues like multi-arc branches and static code analysis complexities. Collaboration and feedback are sought to enhance coverage.py's performance and efficiency.