Branches & merging

A branch is just a movable pointer to a commit. Creating one costs nothing, so the normal way to work is: one branch per feature or bug fix, main always in a working state.

The everyday loop

git switch -c feature/login     # create the branch and move onto it
# ...edit & commit...
git switch main
git merge feature/login
git branch -d feature/login     # delete once merged

git switch (Git 2.23+) is the modern command for moving between branches; git checkout still does the same job but also does several unrelated things, which is why it was split.

git branch                 # list local branches, * marks the current one
git branch -a              # include remote-tracking branches
git switch main            # move to an existing branch
git branch -m old new      # rename a branch

Two kinds of merge

Situation	Result	History
main has not moved since you branched	Fast-forward: the pointer simply slides ahead	Perfectly linear
main gained commits while you worked	Merge commit with two parents	Shows the branch

Force a merge commit even when a fast-forward is possible with git merge --no-ff feature/login. Many teams prefer this so the history shows that a group of commits belonged to one feature.

Keeping a long-running branch fresh

If your branch lives for days, pull main into it regularly so the final merge is small:

git switch feature/login
git fetch origin
git merge origin/main

Small, frequent merges mean small, easy conflicts.

Conflicts

A conflict occurs only when both branches changed the same lines of the same file. Git pauses and writes markers into the file:

<<<<<<< HEAD
TAX_RATE = 0.18
=======
TAX_RATE = 0.12
>>>>>>> feature/login

Fix it in four steps: edit the file into the correct final version, delete every marker line, git add the file, then git commit. git merge --abort puts you back exactly where you started if you want to rethink.

Naming branches

feature/invoice-pdf      new work
fix/gst-rounding         bug fix
chore/upgrade-django     maintenance
hotfix/payment-timeout   urgent production fix

A consistent prefix makes a busy repository readable at a glance, and most tools group branches by it.

Common mistakes

• Committing directly to main "just this once", then being unable to release without the half-done work.
• Letting a branch run for three weeks; the merge becomes a day of conflict resolution.
• Deleting a branch with -D (force) before it is merged, losing the commits.
• Forgetting which branch you are on. Add the branch name to your shell prompt.