Git Branches

What is Git Branch?

Branch is an independent line of development work. As an example, if you are working on a large project and you want to add a new feature, you can't commit all your changes straight away and push them to the default branch, since that would make the commit history pretty messy and it would be hard to tell which changes were made.

Regardless of how big or small your changes are, always create a branch and work on it to encapsulate your changes.

All new commits you make to that branch will be recorded in that branch as well.

Git branch commands

Create branch

git branch <branch-name>

Checkout/Switch branch

Once we have created the branch, we have to switch or checkout to that branch.

• the default branch can still proceed with the commits even though we have checkout to develop branch

git checkout <branch-name>
# if the branch name is not exists, it will auto create and checkout to that branch
git checkout -b <branch-name>

Watch animation

Merge branch (Fast-forward)

The git merge command will combine two branches, so it will consolidate multiple commit sequences into a single history.

Here is the scenario, since develop branch came directly from main and no other changes had been made to main, so it can fast-forward.

git merge <branch>
 
# example, if you want to merge develop branch to main
git checkout main
git merge develop

Watch animation

Merge conflicts

A merge conflict will arise when two developers have changed the same lines in a file. Because of that, Git does not know which one is correct.

To resolve merge conflict, you have to open the file to make necessary changes. Then, use git add command to stage the new merged commit and the final step is to merge your latest commits into it.

git add <file-that-has-conflicts>
git commit -m "merged with <branch> after fixing conflicts"

List branches

git branch
git branch -a # list all local and remote branches

Delete branch

git branch -d <branch-name> # delete branch with safe operation
git branch -D <branch-name> # force delete branch

Rename branch

git branch -m <branch-name> <new-branch-name>
git branch -M <branch-name> <new-branch-name> # force rename branch

Create remote branches and push

Before we want to push our local branches to our remote repository. The remote repository needs to be added to our local project if it hasn't already been. Normally the remote name is origin, but you can change it.

git remote add <remote-name> <remote-repo-url>
# example
git remote add origin https://github.com/KarChunT/git-training

Once you initialize, you have access to this remote repository. So you can push your local branch to the remote at remote name.

• The reason why we need to set-upstream from local to remote is because it makes our jobs easier when we want to perform push and pull operation. With an upstream branch set, you can simply git pull or git push instead of git push origin <branch>

# set-upstream, push the local branch to the remote at remote name
git push -u <remote-name> <local-branch-name>
git push <branch-name> # after you set up-stream, branch-name is optional
git push --force # force push, will overwrite the things in remote
 
# example
git push -u origin develop

You can use the following command:

• if the remote branch already exists or
• you want to change upstream branch

git branch -u origin/<branch-name>