g02_git_merge_vs_rebase.txt

Git merge vs rebase

Merging creates a new commit that combines changes from two branches. 
It preserves the complete chronological history 
but can make the history more complex with many merge commits. 

Rebasing replays your branch's commits on top of another branch, 
creating a linear history (rewriting chronology of commit history)

# Merging starting from feature branch
git checkout main
git merge feature

# rebasing starting from feature branch
git rebase main

Merge is safer for public/shared branches since it doesn't change history

Rebase is better for local branches to maintain clean history before sharing

Warning: never rebase branches that others are working on
When in doubt, merge is the safer option

If there are multiple commits on a feature branch,
you can squash them all together into one commit when merging like this:

# While on main branch
git merge --squash feature
git commit -m "Combined all feature commits"

# -----------------------------------------------------------------
If I am on a feature branch where I have some uncommitted changes 
and I do "git checkout main", what will happen? 
Will I lose uncommitted changes?

If your uncommitted changes don't conflict with files in the main branch,
then Git will carry over your uncommitted changes to the main branch
You won't lose any work

This is called "carrying over" or "bringing changes along"

If your uncommitted changes would conflict with files in main,
Git will block the checkout and show an error message

Your changes will be preserved on your current branch
You'll see a message like "error: Your local changes would 
be overwritten by checkout"

To safely handle uncommitted changes, you can :

# -----------------------------------------------------
# Option 1: Stash your changes
git stash
git checkout main

# Later, to get changes back:
git stash pop

# -----------------------------------------------------
# Option 2: Commit your changes before switching the branch
git commit -m "WIP: temporary commit"
git checkout main

# -----------------------------------------------------
# Option 3: Create a temporary commit and then amend it later
git commit -m "WIP"
git checkout main
# Later, to continue working:
git checkout feature
git add .
git commit --amend

The safest approach is usually to either commit your changes 
or stash them before switching branches. 
This way, you have a clear record of your work and can easily recover it.