Trunk Based Development (TBD) is a software development approach where all developers work on a single branch, often called the "trunk" or "mainline" branch. Here's a more specific breakdown of how TBD works:
Single Branch Development: In TBD, there's only one primary branch where all development work takes place. This means there are no long-lived feature branches or separate branches for different developers. Instead, all changes are made directly to this main branch.
Frequent Commits: Developers commit their changes to the main branch frequently, sometimes multiple times a day. This ensures that changes are integrated into the mainline as soon as they're ready, promoting continuous integration and reducing the likelihood of merge conflicts.
Small, Incremental Changes: TBD encourages developers to make small, incremental changes to the codebase. This helps in keeping the codebase stable and allows for easier integration of changes into the mainline. It also enables faster feedback loops and makes it easier to identify and fix issues.
Continuous Integration (CI): TBD relies heavily on continuous integration practices. Automated tests are run on the main branch whenever new code is committed to ensure that it doesn't break existing functionality. This helps maintain the overall quality of the codebase and prevents the introduction of bugs.
Feature Flags: Feature flags or toggles are often used in TBD to control the rollout of new features. This allows developers to merge their changes into the mainline without exposing them to end-users immediately. Features can then be gradually enabled in production once they've been thoroughly tested.
Code Reviews and Quality Checks: Code reviews are an integral part of TBD to maintain code quality and ensure consistency across the codebase. Additionally, automated code quality checks and static analysis tools may be used to enforce coding standards and catch potential issues early in the development process.
Rollback Strategy: TBD teams must have a robust rollback strategy in place in case a change introduced into the mainline causes problems in production. This could involve quickly reverting to a previous stable version of the codebase or using feature flags to disable problematic features while a fix is implemented.