feat: hide .jj directories by default

Changelog.org

@@ -6,6 +6,7 @@
 *** Added ~treemacs-buffer-name-function~
 *** Added ~treemacs-file-follow-ignore-functions~
 *** Added ~treemacs-buffer-name-prefix~
+*** Added ~treemacs-hide-dot-jj-directory~
 ** v3.1
 - Deprecated ~treemacs-window-background-color~ in favour of ~treemacs-window-background-face~ and
   ~treemacs-hl-line-face~

README.org

@@ -471,6 +471,7 @@ discoverability.
             treemacs-goto-tag-strategy               'refetch-index
             treemacs-header-scroll-indicators        '(nil . "^^^^^^")
             treemacs-hide-dot-git-directory          t
+            treemacs-hide-dot-jj-directory           t
             treemacs-indentation                     2
             treemacs-indentation-string              " "
             treemacs-is-never-other-window           nil
@@ -641,6 +642,7 @@ Treemacs offers the following configuration options (~describe-variable~ will us
 | treemacs-find-workspace-method           | 'find-for-file-or-pick-first                     | Determines how treemacs selects the workspace when it first starts.                                                                                                                                                                  |
 | treemacs-header-scroll-indicators        | '(nil . "^^^^^^")                                | Indicators used for ~treemacs-indicate-top-scroll-mode~.                                                                                                                                                                             |
 | treemacs-hide-dot-git-directory          | t                                                | Indicates whether ~.git~ directories should always be hidden.                                                                                                                                                                        |
+| treemacs-hide-dot-jj-directory           | t                                                | Indicates whether ~.jj~ directories should always be hidden.                                                                                                                                                                         |
 | treemacs-project-follow-into-home        | nil                                              | Indicates whether ~treemacs-project-follow-mode~ can follow into the $HOME directory.                                                                                                                                                |
 | treemacs-move-files-by-mouse-dragging    | t                                                | When non-nil treemacs will move files by dragging with your mouse inside treemacs.                                                                                                                                                   |
 | treemacs-buffer-name-function            | #'treemacs-default-buffer-name                   | Determines the names of treemacs buffers.                                                                                                                                                                                            |

src/elisp/treemacs-core-utils.el

@@ -1034,7 +1034,8 @@ Will return t when FILE
 3) ends with \"~\" (backup files)
 4) is surrounded with \"#\" (auto save files)
 5) is \".git\" (see also `treemacs-hide-dot-git-directory')
-6) is \".\" or \"..\" (default dirs)"
+6) is \".jj\" (see also `treemacs-hide-dot-jj-directory')
+7) is \".\" or \"..\" (default dirs)"
   (declare (side-effect-free t) (pure t))
   (inline-letevals (file)
     (inline-quote
@@ -1046,6 +1047,8 @@ Will return t when FILE
            (string-equal ,file "..")
            (and treemacs-hide-dot-git-directory
                 (string-equal ,file ".git"))
+           (and treemacs-hide-dot-jj-directory
+                (string-equal ,file ".jj"))
            (string-prefix-p "flycheck_" ,file))))))
 
 (define-inline treemacs--mac-ignore-file-predicate (file _)

src/elisp/treemacs-customization.el

@@ -328,6 +328,13 @@ of `treemacs-toggle-show-dotfiles'."
   :type 'boolean
   :group 'treemacs)
 
+(defcustom treemacs-hide-dot-jj-directory t
+  "Indicates whether the .jj directory should be hidden.
+When this is non-nil the .jj dir will be hidden regardless of current setting
+of `treemacs-toggle-show-dotfiles'."
+  :type 'boolean
+  :group 'treemacs)
+
 (defcustom treemacs-sorting 'alphabetic-asc
   "Indicates how treemacs will sort its files and directories.
 Files will still always be shown after directories.

test/treemacs-test.el

@@ -160,7 +160,11 @@
 
       (it "Accepts .git when it is not hidden"
         (-let [treemacs-hide-dot-git-directory nil]
-          (expect (treemacs--reject-ignored-files "~/A/B/C/.git") :to-be t))))
+          (expect (treemacs--reject-ignored-files "~/A/B/C/.git") :to-be t)))
+
+      (it "Accepts .jj when it is not hidden"
+        (-let [treemacs-hide-dot-jj-directory nil]
+          (expect (treemacs--reject-ignored-files "~/A/B/C/.jj") :to-be t))))
 
     (describe "Rejecting"
 
@@ -229,6 +233,9 @@
       (it "Rejects .git"
         (expect (treemacs--reject-ignored-and-dotfiles "~/A/B/C/.git") :to-be nil))
 
+      (it "Rejects .jj"
+        (expect (treemacs--reject-ignored-and-dotfiles "~/A/B/C/.jj") :to-be nil))
+
       (it "Rejects dot"
         (expect (treemacs--reject-ignored-and-dotfiles ".") :to-be nil))