Trunk-based development is a software development approach where all developers work on a single branch (often called the “trunk” or “mainline”) of a version control system, such as Git. In trunk-based development, developers commit their changes directly to this mainline branch without creating long-lived feature branches.
Key characteristics of trunk-based development include:
- Single Branch: There is only one mainline branch, which serves as the primary development branch. All changes, including bug fixes and new features, are committed directly to this branch.
- Frequent Commits: Developers commit their changes to the mainline branch frequently, often multiple times a day. This ensures that changes are integrated and tested continuously.
- Continuous Integration (CI): Continuous Integration practices are typically used to automatically build, test, and validate changes as they are committed to the mainline branch. This helps identify issues early and ensures the mainline branch remains stable.
- Feature Flags: Feature flags or toggles are often used to hide incomplete or experimental features from end-users until they are ready for release. This allows developers to merge changes to the mainline branch without affecting the user experience.
- Rolling Deployments: Changes are continuously deployed to production or staging environments as they are merged into the mainline branch. This enables rapid feedback and allows teams to respond quickly to issues.
Trunk-based development promotes collaboration, reduces integration overhead, and fosters a culture of continuous delivery. However, it requires strong discipline, automated testing, and effective use of feature flags to ensure that changes are always deployable and that the mainline branch remains stable.