Proposal: eglot-base-workspace-configuration

[Ninjananas]

Motivation / Problem

I would like to define a default system-wide eglot-workspace-configuration and override some of it using a .dir-locals.el on a per-project basis.
Unfortunately, setting eglot-workspace-configuration overwrites the whole plist instead of merging the new value with it.

Example:
Let's say that I want to enable globally jedi completion in pylsp
'(:pylsp (:plugins (:jedi_completion (:enabled t))))

And only for a specific project I would like to enable the fuzzy option
'(:pylsp (:plugins (:jedi_completion (:fuzzy t))))

The merged settings would be
'(:pylsp (:plugins (:jedi_completion (:enabled t :fuzzy t))))

Quick solution

I have the following in my init.el:

  (defun custom/merge (a b)
    (if (and (plistp a) (plistp b))
        (map-merge-with 'plist 'custom/merge a b)
      (if b b a)))

  (defvar custom/eglot-base-configuration nil)
  (defvar custom/eglot-workspace-configuration nil)

  (setq-default eglot-workspace-configuration
                (lambda (_server)
                  (custom/merge
                   custom/eglot-base-configuration
                   custom/eglot-workspace-configuration)))

Instead of setting eglot-workspace-configuration in my .dir-locals.el, I set my own custom/eglot-workspace-configuration

Proposal

I think it would be nice to add a new eglot-base-workspace-configuration variable that will be merged by eglot with the existing eglot-workspace-configuration. This does not break existing functionality and makes easier to do what I achieve in my init.el.

I think the "merge" function I'm using works fine for that case, but maybe I'm missing edge cases?

I can try to come out with a pull request if you think that it's a good idea, but I'm not an experienced (e)lisp developer.

Thanks for your time and for the wonderful eglot project !