How to redo the last commit removed with hard reset?

git reflog
git reset --hard HEAD@{1}

To redo a commit removed with hard reset, first find its reference with git reflog. Once you have the reference, restore it with git reset --hard REF.

In the example below we have a repository with 3 commits. The first commit adds articles_controller. The second commit adds the articles_controller.new method and the third commit adds the articles_controller.index method. Git log shows these commits in reversed chronological order.

The last commit is then removed with git reset --hard HEAD~1.

If it turns out that the removed commit is still needed, we can find it's reference with git reflog. In our case the commit is referenced with da3c693 HEAD@{1}: commit: Add articles_controller.index.

The commit is redone with git reset referencing it in git reset --hard HEAD@{1}.

git log --oneline

da3c693 (HEAD -> main) Add articles_controller.index

d09a1a6 Add articles_controller.new

509b108 Add articles_controller

git reset --hard HEAD~1

HEAD is now at d09a1a6 Add articles_controller.new

git reflog

d09a1a6 (HEAD -> main) HEAD@{0}: reset: moving to HEAD~1

da3c693 HEAD@{1}: commit: Add articles_controller.index

d09a1a6 (HEAD -> main) HEAD@{2}: commit: Add articles_controller.new

509b108 HEAD@{3}: commit: Add articles_controller

git reset --hard HEAD@{1}

HEAD is now at da3c693 Add articles_controller.index

See git reflog and git reset to learn more about them.