Editing commit messages with rebase in Git - Practice Problems & Coding Challenges

Challenge - 5 Problems

💻 Command Output

intermediate

Output of interactive rebase command

You run the command git rebase -i HEAD~3 to edit the last 3 commits. What will Git open for you?

A A merge conflict resolution tool.

B A list of all branches in the repository.

C A text editor showing the last 3 commits with options to pick, squash, or edit each commit message.

D The commit history graph in the terminal.

💡 Hint

Think about what interactive rebase is used for.

The command git rebase -i HEAD~3 opens an editor with the last 3 commits listed. You can choose to edit commit messages, reorder commits, squash commits, or drop commits.

🔀 Workflow

intermediate

Steps to change a commit message in the middle of history

You want to change the commit message of the second last commit in your branch. Which sequence of commands correctly achieves this?

A git rebase -i HEAD~2, then change 'pick' to 'reword' for the second commit, save and exit, then edit the message when prompted.

B git commit --amend on the second last commit directly.

C git reset --soft HEAD~2, then git commit with new message.

D git checkout second_last_commit, then git commit --amend.

💡 Hint

Amending only works on the latest commit.

To change a commit message in the middle of history, you use interactive rebase and mark the commit with 'reword' to edit its message.

❓ Troubleshoot

advanced

Error during rebase when editing commit message

You run git rebase -i HEAD~4 and change a commit message, but Git stops with the error: error: could not apply . What is the most likely cause?

A Your Git version does not support interactive rebase.

B There is a conflict between the commit being rebased and later commits that must be resolved manually.

C The commit message contains invalid characters.

D You forgot to save the commit message after editing.

💡 Hint

Think about what happens when commits change history.

During rebase, if changes conflict with later commits, Git pauses and asks you to resolve conflicts before continuing.

🧠 Conceptual

advanced

Effect of rebase on commit hashes after editing messages

After editing a commit message using interactive rebase, what happens to the commit hash of that commit and its descendants?

A The commit hash of the edited commit and all its descendants change because commit hashes depend on commit content.

B Only the edited commit's hash changes; descendants keep their original hashes.

C None of the commit hashes change because messages do not affect hashes.

D Only the descendants' hashes change; the edited commit's hash stays the same.

💡 Hint

Commit hashes are based on the commit content including the message.

Changing a commit message changes the commit content, so its hash changes. This causes all descendant commits to get new hashes as well.

✅ Best Practice

expert

Best practice when rewriting commit messages on a shared branch

You need to rewrite commit messages on a branch that others have already pulled. What is the best practice to avoid problems?

A Rebase and force push immediately without informing anyone.

B Avoid rewriting history; instead, add new commits that fix messages.

C Delete the remote branch and push a new branch with the rewritten history.

D Communicate with your team, perform the rebase locally, then force push the branch with <code>git push --force-with-lease</code>.

💡 Hint

Think about collaboration and safety when rewriting history.

Rewriting history on shared branches can cause problems. Informing the team and using --force-with-lease helps avoid overwriting others' work.