Branching Workflows

This Post is part of a series about Git, Git concepts, commands and usage patterns to remind me and to help me learn. The first post of the series is Git - A New Years Resolution.

There are some common workflows that Git’s lightweight branching makes possible.

Long-Running Branches

As Git uses a simple three-way merge, merging from one branch into another multiple times over a long period is generally easy to do. This means you can have one or several branches that are always open and that you use for different stages of your development cycle; you can merge regularly from some of them into others.

Many Git developers use workflow that embraces this approach, such as having only source code that is entirely stable in the master branch (possibly only code that has been or will be released). Then have another parallel branch named develop or next that they work from or use to test stability  (this branch isn’t necessarily always stable, but whenever it gets to a stable state, it can be merged into master). It’s used to pull in topic branches (short-lived branches, like branch iss53) when they’re ready, to make sure they pass all the tests and don’t introduce bugs.

In reality, this ia all about pointers moving up the line of commits being made. The stable branches are farther down the line in the commit history, and the bleeding-edge branches are farther up the history.

It’s can be easier to think about progressive-stability branching as being a number of work silos, where the sets of commits graduate to a more stable silo when they become fully tested.

You can keep doing this for several levels of stability. Some larger projects also have a proposed or pu (proposed updates) branch that has integrated branches that may not be ready to go into the next or master branch. The idea is that your branches are at various levels of stability; when they reach a more stable level, they’re merged into the branch above them. Again, having multiple long-running branches isn’t necessary, but it’s often helpful, especially when you’re dealing with very large or complex projects. The Linux Kernel Project uses master, topic, next, pu, release and hotfix branches. Only the master branch is long-lived, all the other branches have varying lengths of live spans.

Topic Branches

Topic branches are useful in projects of any size. A topic branch is a short-lived branch that you create and use for a single particular feature or related work. In Git it’s common to create, work on, merge, and delete branches several times a day.

As work is separated into silos where all the changes in that branch have to do with that topic, it’s easier to see what has happened during code review and such. You can keep the changes there for minutes, days, or months, and merge them in when they’re ready, regardless of the order in which they were created or worked on.

It’s important to remember when working with topic branches that they are not necessarily ever shared with the Remote Repository or other developers and as such are local branches. Whenever you’re branching and merging, everything is being done only in your local Git repository and no server communication is happening. It is only when you git push your work (or allow someone to clone from your repository) that these branches have a life beyond your Git repository.

Last modified on 2018-01-13