PRECOG: Pull Request Prioritization and Visualization

A Pull Request (PR) is a code change proposal submitted by a developer for review by other team members. For a reviewer, prioritizing and selecting a PR to review is not easy: this selection can depend on many factors, including the extent of the change, the time available, their state of mind, etc. Existing tools and platforms like GitHub offer support for visualizing code changes and recommending reviewers to assign a PR to. However, little research has been done on providing support to the reviewer to select a PR to review from a list of (assigned) PRs. In this paper, we propose PRECOG, a Visual Studio Code plugin to help reviewers select the appropriate PR by enabling more informed decisions. PRECOG offers a radar chart visualization of the PR’s difficulty across various dimensions, and ranks PRs according to their difficulty. We evaluated PRECOG with 9 developers in a user experiment on the Java Spring Framework. Our results show that although participants differed in how they assess PRs’ difficulty, all agreed that the synthetic view provided by PRECOG helps them make rapid, informed decisions about which PR to review first.