Git pull from/push to a specific branch with magit commands in elisp

Question

When I run magit commands through the magit interface it runs those commands relative to the branch/repository I am currently visiting. However, I am trying to write some code in my config file that will automatically push to or pull from a specific repo, and am not sure how to format magit commands in elisp.

For example, the documentation for magit-pull-from-upstream says:

Pull from the upstream of the current branch.

But what determines the current branch, and how can I specify it? magit-push-current-to-upstream similarly mentions the "current branch".

What I am looking for is a way to call these commands from my config file in elisp code (or similar commands, if these are not the appropriate ones) while specifying which branch of which repo to pull from/push to. Thank you!

Answer 1

Like many Magit commands, the push commands are not really intended to be used non-interactively.

Currently no warning is shown if you use them non-interactively, but that might change. The commands are not considered part of any application programming interface, and I don't make any promises about their "interfaces" staying the same.

Anyway, assuming you know elisp and are also somewhat familiar with Emacs programming concepts (in particular how commands work), then I would assume it to be fairly obvious what you have to do, after looking at the various push commands:

(let ((default-directory "/path/to/local/repo/"))
  (magit-git-push (magit-get-current-branch)
                  (magit-get-upstream-branch)
                  (magit-push-arguments)))

Of course you should also handle the cases when there is no current branch or when it has no upstream. Again, look at magit-push-current-to-upstream for one way of doing that. And since you don't actually want to push to the upstream (I believe), you'll have to adjust that part too.

But what determines the current branch, and how can I specify it?

Look at the code, specifically inside the interactive form; there magit-get-current-branch is being called. That then becomes the value of the BRANCH argument, but only when the command is being called interactively. When it is being called non-interactively as in (magit-push-current-to-upstream ...), then the interactive form is irrelevant, and you have to provide the arguments yourself, which makes it kind of pointless to use this command/function in the first place.

Better use the low-level function as shown above, or if you want to avoid having to write more code than absolutely necessary, then call the command (pseudo-)interactively:

(call-interactively #'magit-push-current-to-upstream)

Answer 2

Current branch is the one currently checked out.

To use a non-current branch and non-default upstream, use the elsewhere option of push or other of pull, which in turn run magit-push-elsewhere and magit-pull, respectivelly.

(cd "/path/to/the/repo")
(magit-pull "origin" "master")