Month: 2025-12 | Repository: jenkinsci/jenkins Overview: In December 2025, I focused on stabilizing the ReverseBuildTrigger workflow by addressing a null threshold issue that could crash builds, and by strengthening test coverage to prevent regressions. This work reduces CI downtime and improves the reliability of automated build triggers critical to downstream pipelines. Key features delivered: - Bug fix: ReverseBuildTrigger Null Threshold Handling Bug Fix to prevent NPE when the upstream threshold is null. Implemented robust handling and ensured the fix aligns with the intended trigger behavior. Major bugs fixed: - Fixed Null Pointer Exception (NPE) in ReverseBuildTrigger caused by a null upstream threshold, which previously could crash build triggers. - Ensured config round-trip does not inadvertently reintroduce null thresholds. - Migrated usage to a non-deprecated ReverseTrigger constructor to reduce future maintenance risk. Overall impact and accomplishments: - Increased stability of CI pipelines by eliminating a class of triggers-related crashes, lowering incident rates and downtime. - Improved test coverage around build triggers (JENKINS-39044) to guard against regressions. - Demonstrated end-to-end fix: code change plus automated tests validated against the associated issue. Technologies/skills demonstrated: - Java, Jenkins core architecture, and build trigger internals - Test-driven development and automated testing for regression coverage - API migration and deprecation handling (non-deprecated constructor usage) - Issue-tracking linkage (JENKINS-39044) and code quality improvements