How to Undo git add / git commit / git push

Goal:

Be able to undo git add.
Be able to undo git commit.
Be able to undo git push.
Be able to delete untracked files.
Be able to restore modified files back to their original state before changes.

Undo git add (Unstage Files)

When you accidentally add files to the staging area that you didn’t intend to include:
You can remove files from the staging area without deleting your actual changes.

# First, check the file status
$ git status

# To unstage a specific file
$ git reset HEAD <file_name>

# To unstage all files from the staging area
$ git reset HEAD

Undo git commit

When you accidentally committed files you didn’t intend to:
If you forgot to include certain files and committed too early.

# Check commit history
$ git log

# 1. Undo the commit but keep the changes staged (as if `git add` was done)
$ git reset --soft HEAD^

# 2. Undo the commit and unstage the changes (files remain in the working directory)
$ git reset --mixed HEAD^  # --mixed is the default, so you can omit it

# 3. Undo the commit and discard all changes (files will be deleted)
$ git reset --hard HEAD^

# If you want to reset your working directory to the latest commit from the remote (not recommended)
$ git reset --hard HEAD

Undo git push

If you're not working on a shared repository, it's usually fine. But if you're collaborating with others, always discuss with your teammates before undoing a push.

Reason:
Commits made after the one you're reverting will be lost.

Personally, I try to avoid canceling a push.
Instead, I prefer modifying the files and committing the changes again.
That way, the edit history is preserved and it's easier for teammates to track what was fixed.

# 1. Undo the latest commit
$ git reset HEAD^

# 2. Check the commit history
$ git log

# 3. Reset the working directory to a specific commit
$ git reset <commit_id>

# 4. After making necessary changes, force push to the remote repository (force push will overwrite remote history)
$ git push -f origin <branch_name>

Appendix 1: Deleting Untracked Files

For some reason, untracked files tend to pile up while working... Since I can't stand messy workspaces, I clean them up pretty often

# Delete untracked files
$ git clean -f

# Delete untracked files and directories
$ git clean -f -d

# Delete untracked files, directories, and ignored files
$ git clean -f -d -x

Appendix 2: Changing Commit Messages