Command for jumping to marker file?

[shouya]

It's quite an often need to jump to the project file of the current project. By project file I mean the file type like Cargo.toml for Rust project, Gemfile for Ruby, mix.exs for Elixir, etc. Incidentally, this kinds of files are usually what's used as marker by projectile.

In general, I wish there is a way to quickly jump to a marker file with one key stroke. The jump need not to be entirely accurate, but hey, projectile-find-test-file isn't accurate all the time either, so I can bare with that.

It's weird I never see any one mention about this feature from the issue list. I myself certainly needed this feature every 10-20 minutes or so when writing any code.

So, currently I simply hacked this command out from scratch. I'm sharing it because I suppose others may also have the same need:

(defun shou/projectile-find-marker-file ()
  "Find the marker file (Cargo.toml, mix.exs, etc) for the current project."
  (interactive)
  (if-let* ((this-file (buffer-file-name))
            (marker-files (projectile-project-type-attribute
                           (projectile-project-type)
                           'marker-files))
            (get-target-marker-file
             (lambda (f)
               (when-let* ((dir (locate-dominating-file default-directory f))
                           (full-path (concat dir f))
                           (_ (not (f-same-p this-file full-path))))
                 full-path)))
            (marker-file (seq-find get-target-marker-file marker-files))
            (target-marker-file (funcall get-target-marker-file marker-file)))
      (find-file target-marker-file)
    (if-let* ((default-directory (f-dirname default-directory))
              (parent-marker-file (seq-find get-target-marker-file marker-files))
              (target-parent-marker-file (funcall get-target-marker-file parent-marker-file)))
        (find-file target-parent-marker-file)
      (message "No marker file found"))))

(with-eval-after-load 'projectile
  (bind-key "m" 'shou/projectile-find-marker-file projectile-command-map))

I could file a PR to add this command to projectile if @bbatsov deems this feature worthful.