Rebase Feature Branches Before Merging
If you want to avoid merge commits, you need to ensure all commits are fast-forwards. You do this by making sure your feature branch rebases cleanly onto your line of development before a merge like so:
git checkout master git checkout -b feature/foo # make some commits git rebase master git checkout master git merge --ff-only feature/foo
Rebase also has a lot of flags, including interactive rebasing with the
-i flag, but you may not need that if you're keeping things as simple as possible and want to preserve all of your branch history on a merge.
Aside from rebasing, the use of the
--ff-only flag will ensure that only fast-forward commits are allowed. A commit will not be made if it would be a merge commit instead. The git-merge(1) manual page says:
Refuse to merge and exit with a non-zero status unless the current HEAD is already up-to-date or the merge can be resolved as a fast-forward.