git revert to undo a commit safely - Practice Problems & Coding Challenges

Challenge - 5 Problems

💻 Command Output

intermediate

What is the output of git revert HEAD?

You run git revert HEAD in a repository where the last commit added a file named notes.txt. What will happen?

A The last commit is deleted from the history permanently.

B A new commit is created that removes <code>notes.txt</code> from the project.

C The repository resets to the commit before the last one, discarding changes.

D Git shows an error saying revert cannot be done on the HEAD commit.

💡 Hint

Think about how git revert works compared to git reset.

git revert HEAD creates a new commit that undoes the changes made in the last commit. It does not delete history but safely reverses changes.

🧠 Conceptual

intermediate

Why is git revert safer than git reset for undoing commits in shared repositories?

Choose the best reason why git revert is preferred over git reset when working with others.

A <code>git revert</code> creates a new commit that undoes changes, preserving history and avoiding conflicts.

B <code>git revert</code> deletes the commit from history, making the repository cleaner.

C <code>git revert</code> automatically merges branches after undoing commits.

D <code>git revert</code> rewrites all commit messages to keep them consistent.

💡 Hint

Think about what happens to commit history and collaboration.

git revert safely undoes changes by adding a new commit, so others' work is not disrupted. git reset rewrites history, which can cause problems if others have based work on those commits.

🔀 Workflow

advanced

Which command sequence correctly reverts a specific commit safely?

You want to undo the commit with hash abc1234 without affecting other commits. Which command sequence is correct?

A git reset --hard abc1234

B git checkout abc1234 && git commit --amend

C git revert abc1234

D git revert HEAD~3

💡 Hint

Focus on reverting a specific commit by its hash.

git revert abc1234 creates a new commit that undoes changes from that commit only. Other options either reset history or target wrong commits.

❓ Troubleshoot

advanced

What error occurs if you try to revert a merge commit without special options?

You run git revert on a merge commit without any extra flags. What error message will Git show?

A warning: merge conflicts detected but revert completed.

B fatal: You are not currently on a branch.

C error: cannot revert because working directory is dirty.

D error: commit <hash> is a merge but no -m option was given.

💡 Hint

Think about what Git needs to know when reverting merges.

Reverting a merge commit requires specifying the parent with -m option. Without it, Git cannot decide which side to revert.

✅ Best Practice

expert

What is the recommended way to undo a commit that has already been pushed to a shared repository?

You accidentally pushed a commit with sensitive data. What is the safest way to undo it without disrupting others?

A Use <code>git revert</code> to create a new commit that removes the sensitive data.

B Use <code>git reset --hard</code> to remove the commit and force push to overwrite history.

C Use <code>git rebase -i</code> to remove the commit and then push normally.

D Delete the remote branch and push a new one without the commit.

💡 Hint

Consider the impact on collaborators and history rewriting.

Using git revert safely undoes changes by adding a new commit. Resetting or rebasing and force pushing rewrites history and can break others' work.