Tuning GitHub for SPL development: branching models & repository operations for product engineers

Abstract

SPLs distinguish between domain engineering (DE) and application engineering (AE). Though each realm has its own lifecycle, they might need to be regularly synchronized to avoid SPL erosion during evolution. This introduces two sync paths: update propagation (from DE to AE) and feedback propagation (from AE to DE). This work looks at how to support sync paths in Version Control Systems (VCSs) using traditional VCS constructs (i.e. merge, branch, fork and pull). In this way, synchronization mismatches can be resolved à la VCS, i.e. highlighting difference between distinct versions of the same artifact. However, this results in a conceptual gap between how propagations are conceived (i.e. update, feedback) and how propagation are realized (i.e. merge, branch, etc). To close this gap, we propose to enhance existing VCSs with SPL sync paths as first-class operations. As a proof-of-concept, we use Web Augmentation techniques to extend GitHub's Web pages with this extra functionality. Through a single click, product engineers can now (1) generate product repositories, (2) update propagating newer feature versions, or (3), feedback propagating product customizations amenable to be upgraded as core assets.