Semantic Versioning

Understanding Semantic Versioning and Its Importance in Git Branching Models

Introduction

In our previous post, we discussed Git branching models and touched on how tags are used to mark specific points in a repository’s history, often to denote version releases. This time, we’re diving deeper into the concept of versioning - specifically, Semantic Versioning - and how it fits into the Git branching model.

What is Semantic Versioning?

Semantic Versioning, or SemVer, is a versioning scheme for software that aims to convey meaning about the underlying changes in a release. It provides a universal standard of structuring version numbers.

A SemVer-compatible version number is composed of three parts: MAJOR.MINOR.PATCH.

• MAJOR: This number is incremented when you make incompatible API changes. This indicates that the new version might break the existing code that uses this API, and manual intervention might be needed to update the code.

• MINOR: This number is incremented when you add functionality in a backward-compatible manner. The users of your API can benefit from the new features without making any changes to their existing code.

• PATCH: This number is incremented when you make backward-compatible bug fixes. This is generally safe to update without worrying about breaking anything.

Additional labels for pre-release and build metadata are also available as extensions to the MAJOR.MINOR.PATCH format, like 1.0.0-alpha or 1.0.0+20130313144700.

One of the essential principles of Semantic Versioning is that a version, once released, should be immutable. This means that no changes should be made to the version after it has been released. If you need to make changes, then it’s important to release a new version. This principle guarantees that every version is a consistent and reliable snapshot of the software at a specific point in time.

Why is Semantic Versioning Important?

Semantic Versioning gives users of your software more insight into what is happening with each new release. It allows them to understand the potential impact of updating to a new version and plan accordingly.

Semantic versioning is particularly useful in a collaborative coding environment as it helps to communicate the risk and the size of changes between different versions of a software or a library.

Semantic Versioning in the Context of Git Branching Models

Semantic Versioning and Git branching models are closely related. As discussed in our previous post, the Git branching model enables parallel lines of development and helps streamline the software release process. When integrated with Semantic Versioning, it makes the process more informative and efficient.

When a new feature, bug fix, or breaking change is introduced into the codebase, it typically goes through the development -> staging -> master workflow. At the point when changes are merged into the master branch and are ready to be released, a new tag is created.

This tag is where Semantic Versioning comes into play. By adhering to the MAJOR.MINOR.PATCH format, the tag conveys important information about what the release encompasses. If the code changes include a new feature that doesn’t break any existing functionality, for instance, the MINOR version would be incremented. If a bug was fixed, the PATCH version would be incremented. And if there were changes that broke backward compatibility, the MAJOR version would be incremented.

For example, if the current version of the application is at 2.3.4 and a new backward-compatible feature is added and ready to be released, the new tag would be 2.4.0.

Conclusion

Understanding Semantic Versioning is essential for managing software versions effectively. It not only provides a standard way of versioning but also communicates the nature of updates to the users. When combined with Git branching models, Semantic Versioning enhances the software development and release process, making it more robust, predictable, and efficient. Remember, effective version management can be as crucial as the code itself in a software project’s success.