Git Version Control

Projected Time

About 2.5 hours

20 minutes for video walkthrough of slides
20 minutes for Guided Practice
30 minutes for Independent Practice
30 min for Group Practice
30 minutes for Challenge
15 minutes for Check for Understanding

Prerequisites

Learning styles represented

See (videos and demonstration)
Hear (videos and demonstration)
Do (Independent & Group Practice)

Motivation

Imagine you are coloring on a flower coloring book. You colored in green for all leaves and now it’s time for the best part, the petal. You know you enjoy red the best but it looked horrible after you finished it. With Git, you can revert your choice of red in a heartbeat and you are free to reapply the red if you change your mind. A work doesn’t have to be permanent; every action is recorded and reversible. (Source: https://dev.to/maestromac/comment/him)

Git is a tool that allows software engineers to keep track of changes they make to code files. They can see the changes they’ve made, changes other people on their team have made to the same file, and even look at line-by-line differences between two files. It’s an integral part of almost every software engineer’s workflow.
Git enables software developers to have access to different versions of their code even when offline.
If you accidentally change your code and break something, git can revert it.
Git lets you backup your code easily to a remote server such as GitHub, just incase your computer gets bad.

Which companies use Git?

Mostly large enterprise companies like Google, Amazon, Mozilla, and Facebook.
Here is the GitHub page of a Mozilla project. Note how:
- It shows different versions of the code at different times(2 years ago, 4 months ago, etc).
- It shows the project contributors(24 contributors).
- It also shows who contributed last (“Latest Commit”).

Objectives

Participants will be able to:

Explain what Git is and why it’s useful
Define basic vocabulary used when talking about Git
Show how to add a file to Git’s tracking system and commit changes made to that file
Show how to work with online repository

Specific Things to Learn

What Git is
Basic Git vocabulary
How a file works it way through Git’s inner system
Workflow for adding and committing a file in Git

Materials

Please watch the video the first time without working along with the demonstration. Just absorb the concepts. Then you can watch the demonstration a second time and code with the instructor if you like.

Git and Version Control (slides)

You can try hands on commands followed in the slides and get an idea of how git works

Common Mistakes / Misconceptions

“Typing commands into the Terminal is scary so I’ll just skip this Git stuff.” There’s really no getting around needing to use Git. It’s OK if typing into the Terminal feels scary at the beginning. As you grow in your skills, using the Terminal will actually become faster than using your mouse and the Finder window!
“I don’t think I’ll ever use this, so I’ll just skip this Git stuff.” You may not be able to see a use for Git now, but once you start working on multi-file projects you’ll hopefully understand why it’s an integral part of almost every software engineering workflow.

Demonstration

Instructor will demonstrate:

Initializing a Git repo
Creating a new file to track with Git
Checking the status of a repo
Adding a file for Git to track
Committing changes to a git repo

Guided Practice

Techtonica staff will assign pairs. Go through the following steps on one pair partner’s computer first, then go through all the steps again the other pair partner’s computer. The repetition of doing this twice will help solidify the new concepts.

Launch your Terminal and run git --version. If a version number appears, you already have git installed. If a version number does not appear:
- Install git via Homebrew: brew install git > If Homebrew isn’t install, check out Command Line Advanced lesson.
- Or run git and follow the prompts to install Git.
Using the Terminal, navigate to the Desktop.
Create a new folder called git_example. Navigate to this folder.
Run the git status command. What happens? Run the git init command to make git_example start keeping track of changes that happen within the folder.
Run git status. What do you see?
Create a new file in git_example called my-favorite-animals.txt.
Run git status. What do you see?
Add some text to my-favorite-animals.txt. Save the file.
Run git status. What do you see?
Run git add my-favorite-animals.txt.
Run git status. What do you see?
Run git commit -m "Create new file..
Run git status. What do you see?

Independent Practice

Spend just 30 minutes working through Git Immersion: A guided tour that walks through the fundamentals of Git, then stop wherever you are. If the first page takes more than a minute to figure out, you can skip it for now.

Group Practice

With computers closed, participants as a group will guide the instructor through creating, adding and committing file changes using Git.

Challenge

Using only the command line:

Create a new directory and initialize a git repo
Create a few files in the directory, and add some dummy text
Add the new files to the stage
Commit with a message, then check the git log to verify that it worked
Change one of the files, then check on the changes with git status and git diff
Add and commit those changes.

Play through githug, a command-line game for learning git. After installing it, type githug in your command-line prompt to play. When you think you’ve solved a level, type githug again to check your work. You’ll get feedback and hints. Please complete at least up to #32: checkout and return to the game throughout the program to practice things like merge and rebase.

Check for Understanding

Form small groups and discuss:

Why do we use Git, and why is it important?
How can you initialize a git repository?
What does the command git status do?
How will you add a file to Git’s tracking system and commit changes made to that file?
How can you check the difference between versions of a file?

Extensions

If you have time, continue the Git Immersion and githug tutorials if you aren’t finished. Also try looking through the supplemental materials. be)