editor/format: add org src-block support

Src blocks can now be reformatted. `+format/buffer` will reformat the
whole src block at point. `+format/region` will format only the
selection (even a subset of a src block).

Closes #3484

modules/editor/format/autoload/format.el

@@ -201,10 +201,33 @@ See `+format/buffer' for the interactive version of this function, and
 ;;
 ;;; Commands
 
+(defun +format--org-region (beg end)
+  "Reformat the region within BEG and END.
+If nil, BEG and/or END will default to the boundaries of the src block at point."
+  (let ((element (org-element-at-point)))
+    (save-excursion
+      (let* ((block-beg (save-excursion
+                          (goto-char (org-babel-where-is-src-block-head element))
+                          (line-beginning-position 2)))
+             (block-end (save-excursion
+                          (goto-char (org-element-property :end element))
+                          (skip-chars-backward " \t\n")
+                          (line-beginning-position)))
+             (beg (if beg (max beg block-beg) block-beg))
+             (end (if end (min end block-end) block-end))
+             (lang (org-element-property :language element))
+             (major-mode (org-src-get-lang-mode lang)))
+        (if (eq major-mode 'org-mode)
+            (user-error "Cannot reformat an org src block in org-mode")
+          (+format/region beg end))))))
+
 ;;;###autoload
 (defun +format/buffer ()
   "Reformat the current buffer using LSP or `format-all-buffer'."
   (interactive)
+  (if (and (eq major-mode 'org-mode)
+           (org-in-src-block-p t))
+      (+format--org-region nil nil)
     (call-interactively
      (cond ((and +format-with-lsp
                  (bound-and-true-p lsp-mode)
@@ -214,7 +237,7 @@ See `+format/buffer' for the interactive version of this function, and
                  (bound-and-true-p eglot--managed-mode)
                  (eglot--server-capable :documentFormattingProvider))
             #'eglot-format-buffer)
-         (#'format-all-buffer))))
+           (#'format-all-buffer)))))
 
 ;;;###autoload
 (defun +format/region (beg end)
@@ -224,6 +247,9 @@ WARNING: this may not work everywhere. It will throw errors if the region
 contains a syntax error in isolation. It is mostly useful for formatting
 snippets or single lines."
   (interactive "rP")
+  (if (and (eq major-mode 'org-mode)
+           (org-in-src-block-p t))
+      (+format--org-region beg end)
     (cond ((and +format-with-lsp
                 (bound-and-true-p lsp-mode)
                 (lsp-feature? "textDocument/rangeFormatting"))
@@ -235,7 +261,7 @@ snippets or single lines."
           ((save-restriction
              (narrow-to-region beg end)
              (let ((+format-region-p t))
-             (+format/buffer))))))
+               (+format/buffer)))))))
 
 ;;;###autoload
 (defun +format/region-or-buffer ()