Core Workflow Lab¶

Practise the everyday loop end to end: initialise a repository, set an identity, stage in whole and in part, commit and amend, inspect history, ignore files, and undo changes at each level. Run every task in a throwaway repository.

Setup¶

Create a fresh sandbox. This lab starts from an empty directory, so there is no first commit yet.

mkdir -p /tmp/git-lab && cd /tmp/git-lab
rm -rf core && mkdir core && cd core

Use example identities only; never paste a real email, token or private remote URL into a lab.

Foundations¶

1. Initialise and Configure¶

Turn the directory into a Git repository, then set the identity and default branch for this repository only.

Solution

git init
git config user.name "Amina Yusuf"
git config user.email "amina@example.com"
git config --show-scope --get user.email   # expect: local  amina@example.com

2. Confirm the Empty State¶

Show that the repository has no commits and the working tree is clean.

Solution

git status          # "No commits yet"
git log 2>&1 || true # fails: no commits to show

Staging and Committing¶

3. First Commit¶

Create service.yml with any content, stage it, and commit it. Confirm the commit shows as the root commit.

Solution

printf 'name: shop\n' > service.yml
git add service.yml
git commit -m "Add service manifest"   # (root-commit) in the summary

4. Stage Part of a File¶

Add two unrelated lines far apart in service.yml, then stage only the first with an interactive add.

Solution

printf 'name: shop\nport: 80\nreplicas: 1\nregion: eu\ntier: free\n' > service.yml
git add -p        # answer y to the first hunk, n to the rest
git status -s     # expect: MM service.yml
git diff --cached # shows only the staged hunk

5. Amend a Commit¶

Commit the staged hunk, then realise you forgot to add a README.md. Add it to the same commit without creating a new one.

Solution

git commit -m "Set service port"
printf '# Shop\n' > README.md
git add README.md
git commit --amend --no-edit
git show --stat HEAD    # both files under the original message

Inspecting History¶

6. Read the Log¶

Make one more commit, then view the history as a compact graph and as a custom one-line format.

Solution

printf 'name: shop\nport: 443\n' > service.yml
git commit -am "Serve on 443"
git log --oneline --graph
git log --pretty=format:'%h %ad %s' --date=short

7. Blame a Line¶

Find which commit last changed the port line in service.yml.

Solution

git blame service.yml    # the port line points at "Serve on 443"
git show $(git blame -s -L /port/,+1 service.yml | awk '{print $1}')

Ignoring Files¶

8. Ignore Generated and Secret Files¶

Create a build/ directory, a .log file and a .env, then ignore all three and confirm they no longer show as untracked.

Solution

mkdir build && printf 'x\n' > build/out.o
printf 'log\n' > app.log
printf 'secret\n' > .env
printf 'build/\n*.log\n.env\n' > .gitignore
git status -s              # only .gitignore is untracked
git check-ignore -v .env   # names the rule that matched

9. Untrack an Already-Committed File¶

Commit a config.env, then decide it should have been ignored. Stop tracking it but keep it on disk.

Solution

printf 'name=shop\n' > config.env
git add -f config.env && git commit -m "Add config"
echo 'config.env' >> .gitignore
git rm --cached config.env      # D staged, file stays on disk
git commit -am "Stop tracking config.env"

Undoing Changes¶

10. Discard an Unstaged Edit¶

Make a bad edit to service.yml, then throw it away and confirm the file is back to the committed version.

Solution

printf 'name: shop\nport: 0\n' > service.yml
git restore service.yml
git status -s     # clean

11. Undo the Last Commit, Keep the Work¶

Make a commit you decide is premature, then undo the commit while keeping its changes staged.

Solution

printf 'name: shop\nport: 443\ndraft: true\n' > service.yml
git commit -am "Draft change"
git reset --soft HEAD~1
git status -sb    # change is staged, commit is gone

12. Revert a Commit Safely¶

Recommit the change from task 11, then back it out with a new commit rather than rewriting history.

Solution

git commit -m "Draft change"
git revert --no-edit HEAD
git log --oneline -2   # original commit plus a Revert commit

13. Clean Untracked Files¶

Create a couple of untracked scratch files, preview what a clean would remove, then remove them.

Solution

printf 'x\n' > scratch.txt && mkdir junk && printf 'y\n' > junk/y.txt
git clean -nd     # dry run: lists what would go
git clean -fd     # removes them
git status        # clean

Cleanup¶

cd /tmp && rm -rf /tmp/git-lab