Lab 12: Git branching and merging

As an exception for this lab only, you may work with a partner on this assignment. However, the logfile you turn in must be of your own git repo.

Setup

Use git, as discussed in Lab 0, to create a repo called gitusername-lab12.

Create the following four new files, with filenames exactly as shown, in this repo after you have cloned it to your computer:

• README
• test.rb
• LICENSE
• index.html

Add some contents to these files – this can be anything.

Using official documentation and tutorials

Git is an industry-standard version control tool that is most useful when working with groups of developers. In this lab, we’re going to walk through a tutorial from git itself to understand how branching and merging work.

While these same topics are covered in numerous videos and websites, it’s hard to know, especially if you are totally new to what you’re doing, what’s a high-quality video/resource versus one that is misleading, incorrect, or inefficient. Videos in particular can be a huge time sink and/or waste of time because it’s difficult to skim them and/or see a summary.

Creating and using branches in git

Branches are used in version control systems like git to help developers organize and limit changes they are making to a (shared) codebase when fixing a bug or making other small, incremental updates. They are a way for these folks to isolate the updates they are working on to a specific branch of the repo, that is, a branch that they create specifically for this purpose. Once they fix their bug, for example, the goal is then to merge this branch back to the main branch of the repository so that other developers can see those updates with git pull.

Next, read and complete the tutorial at the following link: https://git-scm.com/book/en/v2/Git-Branching-Branches-in-a-Nutshell

Note: github has changed the name of the default branch from master to main. When you come to this step in the tutorial instructions, remember to replace master with main. (github is just a hosting service for git; github is not the same thing as git)

Merging branches in git

Now that you understand why and how to creates branches in git, we can learn about how to merge them. For example, when you’ve made a bug fix on some part of your code, reran the test suite to make sure the bug is fixed (and no other tests are broken), you’ll want to merge your changes back with the main git repository so that other people can see these changes.

One issue that might pop up is what happens when two people are updating the same part of their code in their respective branches? Well, first, this is fine and kind of the point of everyone using branches anyway! But sometimes developers will end up with conflicts between different branches for the same piece of code that they might have both updated. Merging branches in git allows us to identify and resolve these conflicts.

Next, read and complete the tutorial at the following link: https://git-scm.com/book/en/v2/Git-Branching-Basic-Branching-and-Merging

Grading rubric and submission

Type the following command to generate a logfile in your repo, which you will submit to BB:
git log --decorate --graph --all >logfile.txt

Item	Points
Your logfile shows all the commands in the two tutorials above working and completed in order	100