Merging

Merging Branches

Branch merging allows the changes from one branch to be added to another, essentially combining the changes.A common scenario in industry is to use branches to work of specific issues, features, or perform code maintainence. Once the edits are complete, the branch's edits are merged back into a master or main branch which contains the code used in production.

Let's demonstrate how to merge branches alongside a bit of review!

Let's create a new branch called copyright-fix from the master branch which we will use to add a copyright message to the footer of our html page:

[user@localhost] $ git checkout -b copyright-fix
Switched to a new branch 'copyright-fix'

info

Notice how the use of the -b option to create and change to the new copyright-fix branch in one command.

Now let's edit index.html to add our copyright message by replacing our previously added "new line" paragraph block:

<!DOCTYPE html>
<html>
    <head>
        <title>Hello World!</title>
        <link rel="stylesheet" href="styles.css">
    </head>

    <body>
        <h1>Hello world!</h1>
        <div>
            <img src="git.png" alt="Git Logo" style="width:100%;max-width:960px">
        </div>
        <p>This is the first file in my new Git Repo.</p>
        <p>Copyright UML Cloud Computing Club &copy;</p>    
    </body>
</html>

tip

Feel free to edit the copyright message to your liking! After all, it's your work!

Let's check the status of the branch to make sure our edits are recorded:

[user@localhost] $ git status 
On branch copyright-fix
Changes not staged for commit:
    (use "git add <file>..." to update what will be committed)
    (use "git restore <file>..." to discard changes in working directory)
        modified:   index.html

no changes added to commit (use "git add" and/or "git commit -a")

Great! Now since our modifications are unstaged, let's go ahead and stage them and then commit them:

[user@localhost] $ git commit -a -m "chore: Added copyright to index.html"
[copyright-fix a618dec] chore: added copyright to footer
 1 file changed, 3 insertions(+)

note

The command above used the -a option to stage and commit all changes in one-step.

Finally, now let's merge our changes back into the master branch!
First we need to checkout to to the master branch.

[user@localhost] $ git checkout master
Switched to branch 'master'

Second, we can now merge master with copyright-fix to combine the changes:

[user@localhost] $ git merge copyright-fix
Updating 0f7809c..a618dec
Fast-forward
 index.html | 3 +++
 1 file changed, 3 insertions(+)

Since we're done working on the copyright-fix branch and it's no longer needed, let's go ahead and delete it using the -d option on the git branch command:

[user@localhost] $ git branch -d copyright-fix
Deleted branch copyright-fix (was 5be7c4a).

Amazing! We successfully managed to add a new piece to our project using branches and sucessfully merged the changes back to the master branch.

Merging Branches​

Merging Branches