Git Crash Course

Commands reference

git clone https://github.com/varbanandreev/git-crash-course.git
git config --local user.name "Git Workshop"
git config --local user.email "[email protected]"
git add .gitignore
git commit -m "Add aws_credentials to gitignore"
git add new_file.txt
git add .gitignore
git commit -m "Add new file"

git revert --no-commit <commit-hash>
git reset HEAD .gitignore
git revert --continue
git checkout -- .gitignore

git add file.txt
git commit -m "Add empty file"
git add file.txt
git stash save "Update file.txt"
git stash pop
git add file.txt
git commit --amend
git reset --soft <commit-hash>

Challenge 1

• Clone the repository locally.
• Change your local user name for this repository to "Git Workshop".
• Change the local user email address for this repository to "[email protected]".
• Create a new empty text file in the repo and name it "new_file.txt".
• Create another text file and name it "aws_credentials.txt". This file will contain sensitive information - write the text below in this file:

[default]
aws_access_key_id=AKIAIOSFODNN7EXAMPLE
aws_secret_access_key=wJalrXUtnFEMI/K7MDENG/bPxRfiCYEXAMPLEKEY

The git status should show the newly created files as untracked files.

• Add "aws_credentials.txt" to the .gitignore.
• Commit the changes made to the .gitignore file only. Name the commit "Add aws_credentials to gitignore".
  Now git status should only show the "new_file.txt".
• Create a new empty text file and name it "ignore_file.txt".
• Add "ignore_file.txt" to the .gitignore.
• Open your "new_file.txt" and write something in it. Save and close the file.
• Stage your changes to both files and commit them with the message "Add new file".
  Now git status shouldn't show anything.
  Your log should have "Git Workshop" as the commit author.

Challenge 2

• Let's imagine that we've made a mistake in our last commit - we shouldn't have committed the new_file.txt changes and we need to revert them.
• But we need to keep the changes to the .gitignore file.
• This can be done with the git revert command, using the --no-commit option and passing the commit hash of the last commit.
• Once you execute the command with this option, git will not directly commit the reverted changes, but will only stage them.
• Now you must un-stage the .gitignore changes and continue with the revert by executing git revert --continue.
• Name your commit "Revert new_file.txt only".
  Now your git log should display your new commit as the most recent one.
• As a final step, undo the changes to the .gitignore that you just un-staged.
  Now your git status shouldn't show anything.

Challenge 3

• Create a new empty text file and name it "file.txt". Stage and commit the file with a commit message "Add empty file".
• Now, let's experiment with the stash functionality. Open "file.txt" and write something in it. Save and close the file. Stage your changes and stash them.
• You can include a message for your stashed changes by using git stash save "<name>". Write "Update file.txt" for your stash message.
• Executing git stash list should show something like: stash@{0}: On master: Update file.txt
• Apply your stashed changes using the git stash pop command. You can use git stash list again to confirm that your stash is now empty.
• Now, let's include the unstashed changes by adding them to the last commit, using the amend option. You must first stage your changes before proceeding with the amend.
• Change the commit message to "Add file".
  Your log should now show the "Add file" commit at the top, and the "Add empty file" commit should be gone.
• The last thing you will do is to reset your last commit, but keeping the changes staged. This can be done by using git reset --soft <commit-hash>.
• Remember, reset affects all commits from the tip to the passed commit. If you want to reset the last commit, you must pass the hash of the commit before it.
• Your log after resetting the commit should no longer contain the "Add file" commit.
• Your status should show a staged file.txt.

Bonus Challenge

• Use the reflog to rewind your repo's state to the point right after Challenge 2 and before Challenge 3. From this state, create a new branch named bonus-challenge. Verify that the branch history looks something like:
  • (HEAD -> bonus-challenge) Revert new_file.txt only
  • Add new file
  • Add aws_credentials to gitignore
  • Initial commit