Git command to checkout any branch and overwrite local changes

Is there a Git command (or a short sequence of commands) that will safely and surely do the following?

• Get rid of any local changes.
• Fetch the given branch from origin if necessary
• Checkout the given branch?

Currently I'm stuck with:

git fetch -p
git stash
git stash drop
git checkout $branch
git pull

but it's bothering me because I'm asked for password two times (by fetch and pull). Generally I would be happy with any solution as long as the password is needed only once.

A couple of notes:

• It's a part of homebrewed deployment script for an application (the code is hosted on GitHub).
• There should be no difference if the branch was already fetched from origin or not (i.e. the first deployment of a new branch shouldn't ideally require any additional steps).
• The script is located on a remote machine that can be accessed by several people, hence no credentials are stored and user/password must be entered (but only once if possible).
• I don't care about any local changes; I always want a pristine copy of the given branch (the further part of deployment script produces local changes).
• I can't clone or export a fresh repository each time; it takes too much time.

Solution 1:

You could follow a solution similar to "How do I force “git pull” to overwrite local files?":

git fetch --all
git reset --hard origin/abranch
git checkout abranch 

That would involve only one fetch.

With Git 2.23+, git checkout is replaced here with git switch (presented here) (still experimental).

git switch -f $branch

(with -f being an alias for --discard-changes, as noted in Jan's answer)

Proceed even if the index or the working tree differs from HEAD.
Both the index and working tree are restored to match the switching target.

If you do not want to switch branch, but only restore a folder from another branch, then git restore is the other command which replaces the old obsolete and confusing git checkout.
I presented git restore here.

git restore --source=anotherBranch --staged] [--worktree -- aFolder
# or, shorter:
git restore -s anotherBranch -SW -- aFolder

Solution 2:

Couple of points:

• I believe git stash + git stash drop could be replaced with git reset --hard

• ... or, even shorter, add -f to checkout command:

  git checkout -f -b $branch
  

  That will discard any local changes, just as if git reset --hard was used prior to checkout.

As for the main question: instead of pulling in the last step, you could just merge the appropriate branch from the remote into your local branch: git merge $branch origin/$branch, I believe it does not hit the remote. If that is the case, it removes the need for credensials and hence, addresses your biggest concern.

Solution 3:

git reset and git clean can be overkill in some situations (and be a huge waste of time).

If you simply have a message like "The following untracked files would be overwritten..." and you want the remote/origin/upstream to overwrite those conflicting untracked files, then git checkout -f <branch> is the best option.

If you're like me, your other option was to clean and perform a --hard reset then recompile your project.

Solution 4:

The new git-switch command (starting in GIT 2.23) also has a flag --discard-changes which should help you. git pull might be necessary afterwards.

Warning: it's still considered to be experimental.