InfoQ - JUnit https://www.infoq.com InfoQ JUnit feed Uber Migrates 75,000+ Test Classes from Junit 4 to Junit 5 Using Automated Code Transformation https://www.infoq.com/news/2026/04/uber-junit4-junit5-migration/?utm_campaign=infoq_content&utm_source=infoq&utm_medium=feed&utm_term=JUnit <img src="https://res.infoq.com/news/2026/04/uber-junit4-junit5-migration/en/headerimage/generatedHeaderImage-1776546803798.jpg"/><p>Uber engineers migrated over 75,000 test classes from JUnit 4 to JUnit 5 using automated code transformation with OpenRewrite and internal orchestration. By enabling the JUnit Platform for dual execution with Bazel and validating changes through CI, the team modernized testing infrastructure while maintaining correctness at monorepo scale.</p> <i>By Leela Kumili</i> Productivity Large Concept Models Developer Experience AI Development JUnit Test Automation Unit Testing migration AI Coding Orchestration Bazel AI, ML & Data Engineering Development Architecture & Design news Mon, 27 Apr 2026 14:07:00 GMT https://www.infoq.com/news/2026/04/uber-junit4-junit5-migration/?utm_campaign=infoq_content&utm_source=infoq&utm_medium=feed&utm_term=JUnit Leela Kumili 2026-04-27T14:07:00Z /news/2026/04/uber-junit4-junit5-migration/en