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Git Notes

Table of Contents​

Cool Git Commands​

Merge Main into your branch​

# checkout main and pull latest code
git checkout main
git pull

# checkout your branch
git checkout my-branch

# merge the main branch into your branch
git merge main

Squash Commits​

  • I don't typically do this because I like seeing incremental changes but if the git history gets too messy, here is a good way to squash some commits:

Let's say that you want to adjust the last 5 commits:

git rebase -i HEAD~5
  • And then when the interactive git editor shows up in VS Code, you can select which commit messages to keep by choosing pick and which ones to toss by selecting squash.
  • You then pick the messages you want to keep. You can write a new message OR just comment out the old ones with # next to it and just leave one message.

Reset to Origin Branch​

Sometimes I just want to pull whatever is on a particular branch, regardless of what I have locally. Here is an example of hard pulling the staging branch:

# resets to whatever is on origin/staging
git reset --hard origin/staging

Reset to the last commit​

# reset to the last commit; gets rid of all local changes
git reset --hard

Reverting a commit​

# to see a list of the commits
git log --oneline

# find the commit you want to revert to and copy the hash
75e7912 My awesome commit message

# revert to that commit
git revert 75e7912
git push

Reverting a merge commit​

Merge commits are a special case. If you're trying to revert a merge commit, this is what you need to do:

git revert git_sha -m 1

The first part, git revert git_sha, makes sense. It's the second part, -m 1, that is tricky. The -m flag is only used when reverting a merge commit. -m stands for "mainline", and the number (usually 1 or 2) tells Git which parent to treat as the base.

Here is how you can visualize it - merge commits have two parents:

Merge commit
│
├── Parent 1 (usually the base branch)
└── Parent 2 (usually the feature branch)

-m 1 treats Parent 1 as the main line. And this command git revert git_sha -m 1 keeps everything from main before the merge, but undoes the changes introduced by the PR.

List the commits in the current branch vs. another branch​

I found this trying to understand why there were so many commits in my branch (more than usual). The command has a number of different parts to it (that I don't entirely understand). Here's the command and some notable parts:

git log main..HEAD --pretty=oneline
  • git log: just a list of commits
  • main..HEAD: the commits in the main branch that are not in the HEAD branch
  • --pretty=oneline: format the output to be more readable

Remove pnpm-lock.yaml file from a commit​

  • I had a situation where I needed to remove changes to the pnpm-lock.yaml file. Simply re-running pnpm i wouldn't fix it because there were particular issues with one of our submodules so the best thing to do was to just remove the changes. After squashing my old commits into one commit, I ran these commands:
# Unstages the pnpm-lock.yaml from the last commit and restores it to the state before that commit.
git reset HEAD^ -- pnpm-lock.yaml

# Amends the last commit without changing its message, keeping the current staged changes.
git commit --amend --no-edit

# Force-pushes the rewritten commit history to the remote branch.
git push --force

Use pnpm-lock.yaml file from main​

git checkout feature-branch
git checkout origin/main -- pnpm-lock.yaml
git add .
git commit -m "Update pnpm-lock"
git push

You can also do a rebase if you want to clean-up the code

Git Worktree​

Adding an Empty Commit​

Sometimes you might want to create an empty commit, which is a commit that doesn't change any files but can be useful for triggering CI/CD pipelines or marking a point in history.

git commit --allow-empty -m "This is an empty commit"

This command creates a commit with the specified message but without any changes to the files.