Insert and expand snippet when committing with Magit

Question

I use a template with Git for keeping my commits messages neat and professional, as explained here.

However, since I use Magit, I would like to insert and expand a snippet with Yasnippets because Yasnippet is more dynamic than a static template.

I would like to know how to trigger the insertion and expansion of a snippet when the buffer for writing the commit message opens in Magit.

Answer 1

Magit comes with the minor mode git-commit-mode, enabled via the entry-point global-git-commit-mode, which runs the hook and user option git-commit-setup-hook as its last step. You can add your git-commit-mode-specific setup code to this as you would any other hook variable:

(add-hook 'git-commit-setup-hook #'my-git-commit-setup-yasnippet)

or

(add-hook 'git-commit-setup-hook
          (lambda ()
            (do-something-with-yasnippet)))

You could also use the Customize interface to achieve this via M-x customize-option RET git-commit-setup-hook RET. Either way I recommend you look at the documentation and suggested and already enabled hook functions reported by Customize for this hook.

The setup code for git-commit-mode also enables an arbitrary major mode which controls the overall editing behaviour for commit messages. This mode is determined by the user option git-commit-major-mode. Thus the hook for whichever major mode you specify could offer another means of running custom setup code.