Undoing Mistakes Safely

Almost every Git mistake is recoverable. The skill is choosing the right tool for the stage the change is in.

Working Directory

To throw away uncommitted changes in a file, restore it from the last commit.

git restore index.html
git restore .

Staged Changes

Unstage a file but keep its changes in the working directory.

git restore --staged index.html

Last Commit

If you have not pushed, amend the message or add a forgotten file. Do not amend a commit others already have.

git add forgotten.css
git commit --amend -m "Add homepage styles"

Shared Commits

git revert creates a new commit that undoes an earlier one. It is safe for shared history because it does not rewrite anything.

git revert a1b2c3d

Practice

1. Make a change, stage it, unstage it and discard it.
2. Amend the message of your most recent unpushed commit.
3. Revert a commit and inspect the new history.

Hands-on exercise

1. Create a commit with a typo in the message.
2. Amend the message.
3. Make a second commit that breaks something.
4. Revert the second commit and confirm the file is back to its previous state.

Recap

Restore for files, restore --staged to unstage, amend before pushing and revert for shared history.