Git branching and merging

What are branches?

Copy of your project
Copy is usually created from the “main” branch
Used to work on a new feature, solve a bug or refine an existing feature
Advantage: your main branch stays in a working state, while you work on new code in the copy or “feature branch”

What are branches?

Rule of thumb for branches:
- One branch –> one purpose
- Need at least one version of the code to “work” (to compile, to give expected results, …) –-> “Main” or “Master”
- At the same time we work on a new feature, or maybe several features concurrently –> feature branches
- We need to be able to separate different lines of work really well.

Your turn: experiment with branches

To experiment with branches we will create a “fork” from our recipe GitHub repository:

Go to https://tinyurl.com/uu-recipes
Click on the Dropdown menu “Fork” and “Create new fork”
Make sure the box “Copy the main branch only” is checked

Create a new branch from “main”:

Click on “branches”
Click on “New branch” and give the new branch a name e.g. “cakes”
Create a new file called “cakes/chocolate_cake.md” and “commit”
Merge the branch “cake” into “main” to update the content there

Working with branches on your laptop

Clone the recipe repository to your laptop:

git clone git@github.com:<user>/recipe-book.git
cd recipe-book

Create a new branch “cheesecake” in the webinterface
“Pull” the changes to your computer:
```
git pull
```

Exercise: Create and commit to the new branch

Add a cheesecake recipe to your local repository on the “cheesecake” branch
Commit the changes and push them
Verify in the web browser that the files in “main” and the “cheesecake” branch differ.
Merge the two branches in the web interface through creating a “Pull request”

Summary

In this part of the tutorial we saw:

How to create branches in the remote repository through the web interface
How we can update the content of branches
How we can merge changes from one branch into another branch

Creating branches on your laptop

We will now create a new branch in your local repository on your laptop.
The branch will be merged into “main” in your local repository.
Finally we will update the “main” branch on GitHub.

Please follow along on your git bash or terminal.

Summary

In this part of the tutorial we showed:

How to create a branch only in your local repository and how to update its contents
How to merge the changes from the branch in your local repository into the main branch in your local repository

Issues

In GitHub users of your code or you yourself can create “issues”.
An issue can be a feature request, a bug or simply a “Todo” for your project.
You can create a branch for an issue to track how far the issue is solved. GitHub will link them for you.

Merge conflicts

Let us create a merge conflict and see how we can resolve it!