Continuous Integration

Continuous Integration (CI) is the practice of frequently merging code changes from multiple developers into a shared main branch in a version control repository like Git. The goal is to detect bugs and integration issues as early as possible. CI relies on developers committing their changes to the repo multiple times per day. After each commit, an automated build process kicks off to compile the code and run tests. If any test fails, the team is notified immediately so the culprit commit can be identified and fixed.

For CI to work well, teams need a robust test suite with unit, integration, and regression tests. Tests should run quickly so developers get feedback within 10-20 minutes after committing changes. Common CI tools include Jenkins, CircleCI, TravisCI, and GitHub Actions. These tools automate the repetitive parts of CI like running builds, tests, and notifications. Overall, CI improves software quality and developer productivity by catching issues early and encouraging collaboration. Teams can ship updates more frequently and confidently with CI.