[nongnu] elpa/eldoc-diffstat e954a705f1 2/6: Address review comments (on emacs-devel)

[ELPA Syncer]

branch: elpa/eldoc-diffstat
commit e954a705f1e34fbb42c62fe5a067c2413b685c30
Author: Johann Klähn <johann@jklaehn.de>
Commit: Johann Klähn <johann@jklaehn.de>

    Address review comments (on emacs-devel)
    
    Cf. https://lists.gnu.org/archive/html/emacs-devel/2024-12/msg00369.html
    
    Suggested-by: Philip Kaludercic <philipk@posteo.net>
    Suggested-by: Tassilo Horn <tsdh@gnu.org>
---
 .elpaignore       |  2 ++
 README.md         | 11 +++++++++-
 eldoc-diffstat.el | 63 +++++++++++++++++++++++++++++++------------------------
 3 files changed, 48 insertions(+), 28 deletions(-)

diff --git a/.elpaignore b/.elpaignore
new file mode 100644
index 0000000000..daa22c07ac
--- /dev/null
+++ b/.elpaignore
@@ -0,0 +1,2 @@
+.gitignore
+screenshot.webp
diff --git a/README.md b/README.md
index 5279e15a8a..732407ac2b 100644
--- a/README.md
+++ b/README.md
@@ -5,7 +5,16 @@ It supports Git and Mercurial repositories.
 
 ![A screenshot showing diffstat information in the echo area of a magit-log 
buffer.](screenshot.webp "diffstat information is available in the echo area.")
 
-To use, call `eldoc-diffstat-setup` in the desired buffer or mode hook.
+To use, call `eldoc-diffstat-setup` in the desired buffer or mode hook, e.g.:
+
+```elisp
+(add-hook 'git-rebase-mode-hook #'eldoc-diffstat-setup)
+(add-hook 'log-view-mode-hook #'eldoc-diffstat-setup)
+(add-hook 'magit-log-mode-hook #'eldoc-diffstat-setup)
+(add-hook 'magit-status-mode-hook #'eldoc-diffstat-setup)
+(add-hook 'vc-annotate-mode-hook #'eldoc-diffstat-setup)
+```
+
 You might also want to add the following to your config:
 
 ```elisp
diff --git a/eldoc-diffstat.el b/eldoc-diffstat.el
index a9dcc41854..04636a906c 100644
--- a/eldoc-diffstat.el
+++ b/eldoc-diffstat.el
@@ -61,6 +61,23 @@ a property to the process object.")
         "--stat" "--rev"))
   "Alist mapping VCS backend to the command to use for computing the 
diffstat.")
 
+(defconst eldoc-diffstat--output-regex
+  (rx buffer-start
+      ;; 1: commit author and date
+      ;; 2: newline between author info and subject (will be removed)
+      (group-n 1 (+ not-newline)) (group-n 2 ?\n)
+      ;; subject / first line of commit message
+      (+ not-newline) ?\n
+      ;; 3: point after subject / before diffstat (shortstat will be moved 
here)
+      (group-n 3)
+      ;; diffstat for individual files
+      (+? anything)
+      ;; 4: shortstat, i.e., total # of modified files + added/deleted lines
+      (group-n 4 (+ not-newline) ?\n)
+      (* space) buffer-end)
+  "Regular expression used to rewrite and apply faces to diffstat output.
+Has to match `eldoc-diffstat--commands'.")
+
 ;;;###autoload
 (defun eldoc-diffstat-setup ()
   "Configure eldoc buffer-locally to display diffstat for revision at point."
@@ -77,7 +94,7 @@ Intended for `eldoc-documentation-functions'."
               (backend (car info))
               (revision (cdr info))
               (command (alist-get backend eldoc-diffstat--commands)))
-    (if-let ((result (eldoc-diffstat--get-cache info)))
+    (if-let* ((result (eldoc-diffstat--get-cache info)))
         (funcall callback result)
       (eldoc-diffstat--docstring-1 (append command (list revision)) callback 
info))))
 
@@ -87,11 +104,11 @@ The returned record should be a cons cell of the form 
(BACKEND . REVISION) where
 BACKEND is a symbol representing the version control system and REVISION is
 a string identifying the specific revision."
   (cond
-   ((when-let (((fboundp 'magit-stash-at-point))
-               (revision (magit-stash-at-point)))
+   ((when-let* (((fboundp 'magit-stash-at-point))
+                (revision (magit-stash-at-point)))
       (cons 'Git revision)))
-   ((when-let (((fboundp 'magit-commit-at-point))
-               (revision (magit-commit-at-point)))
+   ((when-let* (((fboundp 'magit-commit-at-point))
+                (revision (magit-commit-at-point)))
       (cons 'Git revision)))
    ((and (derived-mode-p 'git-rebase-mode)
          (fboundp 'git-rebase-current-line)
@@ -154,35 +171,27 @@ caching the result, see `eldoc-diffstat--get-cache' for 
details."
         (funcall callback result)))))
 
 (defun eldoc-diffstat--format-output-buffer ()
-  "Format the diffstat output."
+  "Format the diffstat output in the current buffer."
   ;; Translate color control sequences into text properties.
   (let ((ansi-color-apply-face-function
          (lambda (beg end face)
            (put-text-property beg end 'face face))))
     (ansi-color-apply-on-region (point-min) (point-max)))
 
-  ;; Delete trailing blank lines.
-  (goto-char (point-max))
-  (delete-blank-lines)
-
-  ;; Make first line bold.
   (goto-char (point-min))
-  (put-text-property (point)
-                     (line-end-position)
-                     'face 'bold)
-
-  ;; Join second line.
-  (forward-line)
-  (join-line)
-
-  ;; Move summary to the top and make it italic.
-  (forward-line)
-  (reverse-region (point) (point-max))
-  (put-text-property (point)
-                     (line-end-position)
-                     'face 'italic)
-  (forward-line)
-  (reverse-region (point) (point-max)))
+  (when (looking-at eldoc-diffstat--output-regex)
+    ;; Make commit author and date bold.
+    (put-text-property
+     (match-beginning 1) (match-end 1) 'face 'bold)
+
+    ;; Join the first two lines.
+    (replace-match " " nil nil nil 2)
+
+    ;; Move summary to the second line and make it italic.
+    (let ((summary (delete-and-extract-region
+                    (match-beginning 4) (match-end 4))))
+      (replace-match
+       (propertize summary 'face 'italic) nil nil nil 3))))
 
 (provide 'eldoc-diffstat)
 ;;; eldoc-diffstat.el ends here