feat(modeline): mode icons, status segments, and a repair command

I rebuilt the custom modeline as pure segment helpers with thin :eval wiring:

- The nerd-icons mode icon replaces the mode-name text (cached per buffer, plain name on terminal frames), with the full mode name in the help-echo.
- New left-side segments: modified dot / read-only lock (file buffers only), remote @host tag, Narrow tag that widens on click, point-based percentage, region selection info, and a MACRO tag while a keyboard macro records.
- New right-side segments: mode-line-process (eat and compilation state was invisible) and flycheck per-severity counts with click-through to the error list, replacing the stock status text. Glyphs are nerd-icons private-use codepoints so emojify can't rewrite them, with text fallbacks when icons are unavailable.
- cj/modeline-reset kills a hijacked buffer-local mode-line-format (two-column mode, ediff, calc).
- Optional taller bar via cj/modeline-height-factor, a display height property on the padding space so the theme's mode-line faces stay untouched.
- Housekeeping: the dead user-constants require and stale commentary are gone, cj/modeline-vc-faces left the risky-local-variable list, and the cache-key defun is cj/--modeline-vc-cache-key so it no longer shadows the same-named defvar.

Percent signs from :eval strings go through the mode-line %-construct pass, so the position segment emits %% for a literal percent.

6 files changed, 291 insertions, 8 deletions

diff --git a/tests/test-modeline-config-buffer-status.el b/tests/test-modeline-config-buffer-status.el
new file mode 100644
index 00000000..123f1062
--- /dev/null
+++ b/tests/test-modeline-config-buffer-status.el
@@ -0,0 +1,73 @@
+;;; test-modeline-config-buffer-status.el --- buffer-status segment -*- lexical-binding: t; -*-
+
+;;; Commentary:
+;; Tests for `cj/--modeline-buffer-status': the modified / read-only
+;; indicator.  Read-only wins over modified; the modified dot shows only
+;; for file-visiting buffers (special buffers are perpetually modified
+;; and would be noise); clean file buffers show nothing.
+
+;;; Code:
+
+(require 'ert)
+
+(add-to-list 'load-path (expand-file-name "modules" user-emacs-directory))
+
+(require 'modeline-config)
+
+(ert-deftest test-modeline-config-buffer-status-modified-file-shows-dot ()
+  "Normal: a modified file-visiting buffer returns the warning-faced dot."
+  (let ((file (make-temp-file "modeline-status-" nil ".txt")))
+    (unwind-protect
+        (with-current-buffer (find-file-noselect file)
+          (insert "x")
+          (let ((status (cj/--modeline-buffer-status)))
+            (should (stringp status))
+            (should (string-match-p "●" status))
+            (should (eq (get-text-property
+                         (string-match "●" status) 'face status)
+                        'warning)))
+          (set-buffer-modified-p nil)
+          (kill-buffer))
+      (delete-file file))))
+
+(ert-deftest test-modeline-config-buffer-status-clean-file-nil ()
+  "Normal: an unmodified file-visiting buffer returns nil."
+  (let ((file (make-temp-file "modeline-status-" nil ".txt")))
+    (unwind-protect
+        (with-current-buffer (find-file-noselect file)
+          (should-not (cj/--modeline-buffer-status))
+          (kill-buffer))
+      (delete-file file))))
+
+(ert-deftest test-modeline-config-buffer-status-read-only-shows-lock ()
+  "Normal: a read-only buffer returns the read-only indicator."
+  (with-temp-buffer
+    (setq buffer-read-only t)
+    (let ((status (cj/--modeline-buffer-status)))
+      (should (stringp status))
+      (should (> (length status) 0)))))
+
+(ert-deftest test-modeline-config-buffer-status-read-only-wins-over-modified ()
+  "Boundary: read-only + modified shows the read-only indicator, not the dot."
+  (let ((file (make-temp-file "modeline-status-" nil ".txt")))
+    (unwind-protect
+        (with-current-buffer (find-file-noselect file)
+          (insert "x")
+          (setq buffer-read-only t)
+          (let ((status (cj/--modeline-buffer-status)))
+            (should (stringp status))
+            (should-not (string-match-p "●" status)))
+          (setq buffer-read-only nil)
+          (set-buffer-modified-p nil)
+          (kill-buffer))
+      (delete-file file))))
+
+(ert-deftest test-modeline-config-buffer-status-modified-non-file-nil ()
+  "Boundary: a modified non-file buffer (scratch-like) returns nil."
+  (with-temp-buffer
+    (insert "x")
+    (should (buffer-modified-p))
+    (should-not (cj/--modeline-buffer-status))))
+
+(provide 'test-modeline-config-buffer-status)
+;;; test-modeline-config-buffer-status.el ends here
diff --git a/tests/test-modeline-config-flycheck-render.el b/tests/test-modeline-config-flycheck-render.el
new file mode 100644
index 00000000..46d0cdef
--- /dev/null
+++ b/tests/test-modeline-config-flycheck-render.el
@@ -0,0 +1,51 @@
+;;; test-modeline-config-flycheck-render.el --- flycheck counts rendering -*- lexical-binding: t; -*-
+
+;;; Commentary:
+;; Tests for `cj/--modeline-flycheck-render', the pure formatter that
+;; turns a flycheck counts alist ((error . N) (warning . M) ...) into a
+;; propertized modeline string.  Errors carry the error face, warnings
+;; the warning face; zero-count severities are omitted; an all-clean
+;; alist (or nil) renders nothing.  Glyphs come from nerd-icons when
+;; available (private-use codepoints, safe from emojify) with plain-text
+;; fallbacks in batch mode.
+
+;;; Code:
+
+(require 'ert)
+
+(add-to-list 'load-path (expand-file-name "modules" user-emacs-directory))
+
+(require 'modeline-config)
+
+(ert-deftest test-modeline-config-flycheck-render-errors-and-warnings ()
+  "Normal: both counts render, error face on errors, warning on warnings."
+  (let ((s (cj/--modeline-flycheck-render '((error . 2) (warning . 5)))))
+    (should (stringp s))
+    (should (string-match-p "2" s))
+    (should (string-match-p "5" s))
+    (let ((epos (string-match "2" s))
+          (wpos (string-match "5" s)))
+      (should (eq (get-text-property epos 'face s) 'error))
+      (should (eq (get-text-property wpos 'face s) 'warning)))))
+
+(ert-deftest test-modeline-config-flycheck-render-errors-only ()
+  "Normal: warnings absent when their count is zero or missing."
+  (let ((s (cj/--modeline-flycheck-render '((error . 3)))))
+    (should (stringp s))
+    (should (string-match-p "3" s))
+    (should-not (text-property-any 0 (length s) 'face 'warning s))))
+
+(ert-deftest test-modeline-config-flycheck-render-clean-nil ()
+  "Boundary: zero counts render nothing."
+  (should-not (cj/--modeline-flycheck-render '((error . 0) (warning . 0)))))
+
+(ert-deftest test-modeline-config-flycheck-render-nil-input ()
+  "Boundary: nil counts alist renders nothing."
+  (should-not (cj/--modeline-flycheck-render nil)))
+
+(ert-deftest test-modeline-config-flycheck-render-info-ignored ()
+  "Boundary: info-level counts alone render nothing (errors/warnings only)."
+  (should-not (cj/--modeline-flycheck-render '((info . 4)))))
+
+(provide 'test-modeline-config-flycheck-render)
+;;; test-modeline-config-flycheck-render.el ends here
diff --git a/tests/test-modeline-config-flycheck-segment.el b/tests/test-modeline-config-flycheck-segment.el
index 2ae2f5de..ed4d0601 100644
--- a/tests/test-modeline-config-flycheck-segment.el
+++ b/tests/test-modeline-config-flycheck-segment.el
@@ -2,7 +2,7 @@
 
 ;;; Commentary:
 ;; Smoke test that the custom modeline's `mode-line-format' includes
-;; a guarded reference to `flycheck-mode-line-status-text', and that
+;; a guarded reference to `cj/--modeline-flycheck-status', and that
 ;; the guard requires both `mode-line-window-selected-p' and
 ;; `bound-and-true-p flycheck-mode'.  See
 ;; docs/specs/flycheck-modeline-customization-spec-implemented.org for the design.
@@ -16,9 +16,9 @@
 (require 'modeline-config)
 
 (ert-deftest test-modeline-config-flycheck-segment-present ()
-  "`mode-line-format' contains an :eval form invoking flycheck-mode-line-status-text."
+  "`mode-line-format' contains an :eval form invoking cj/--modeline-flycheck-status."
   (let ((printed (format "%S" (default-value 'mode-line-format))))
-    (should (string-match-p "flycheck-mode-line-status-text" printed))))
+    (should (string-match-p "cj/--modeline-flycheck-status" printed))))
 
 (ert-deftest test-modeline-config-flycheck-segment-guarded-by-active-window ()
   "Flycheck segment gates on `mode-line-window-selected-p'."
diff --git a/tests/test-modeline-config-reset.el b/tests/test-modeline-config-reset.el
new file mode 100644
index 00000000..54b7bb2f
--- /dev/null
+++ b/tests/test-modeline-config-reset.el
@@ -0,0 +1,37 @@
+;;; test-modeline-config-reset.el --- cj/modeline-reset -*- lexical-binding: t; -*-
+
+;;; Commentary:
+;; Tests for `cj/modeline-reset', the repair command for buffers whose
+;; `mode-line-format' was hijacked buffer-locally (two-column mode, ediff,
+;; calc).  It kills the buffer-local value so the default format returns.
+
+;;; Code:
+
+(require 'ert)
+
+(add-to-list 'load-path (expand-file-name "modules" user-emacs-directory))
+
+(require 'modeline-config)
+
+(ert-deftest test-modeline-config-reset-kills-local-format ()
+  "Normal: a hijacked buffer-local mode-line-format is removed."
+  (with-temp-buffer
+    (setq-local mode-line-format '("hijacked"))
+    (should (local-variable-p 'mode-line-format))
+    (cj/modeline-reset)
+    (should-not (local-variable-p 'mode-line-format))
+    (should (eq mode-line-format (default-value 'mode-line-format)))))
+
+(ert-deftest test-modeline-config-reset-noop-without-local ()
+  "Boundary: harmless when the buffer has no local mode-line-format."
+  (with-temp-buffer
+    (should-not (local-variable-p 'mode-line-format))
+    (cj/modeline-reset)
+    (should-not (local-variable-p 'mode-line-format))))
+
+(ert-deftest test-modeline-config-reset-is-a-command ()
+  "Normal: cj/modeline-reset is interactive."
+  (should (commandp #'cj/modeline-reset)))
+
+(provide 'test-modeline-config-reset)
+;;; test-modeline-config-reset.el ends here
diff --git a/tests/test-modeline-config-segments.el b/tests/test-modeline-config-segments.el
new file mode 100644
index 00000000..580a7711
--- /dev/null
+++ b/tests/test-modeline-config-segments.el
@@ -0,0 +1,122 @@
+;;; test-modeline-config-segments.el --- small modeline segments -*- lexical-binding: t; -*-
+
+;;; Commentary:
+;; Tests for the small pure segment helpers added in the 2026-07-01
+;; modeline overhaul: macro indicator, remote-host tag, narrowing
+;; indicator, position/region info, and the padding space.
+
+;;; Code:
+
+(require 'ert)
+
+(add-to-list 'load-path (expand-file-name "modules" user-emacs-directory))
+
+(require 'modeline-config)
+
+;; ---------------------------- Macro Indicator --------------------------------
+
+(ert-deftest test-modeline-config-macro-indicator-shows-when-defining ()
+  "Normal: MACRO text with the error face while a macro is recording."
+  (let ((defining-kbd-macro t))
+    (let ((s (cj/--modeline-macro-indicator)))
+      (should (stringp s))
+      (should (string-match-p "MACRO" s))
+      (should (eq (get-text-property (string-match "MACRO" s) 'face s)
+                  'error)))))
+
+(ert-deftest test-modeline-config-macro-indicator-nil-when-idle ()
+  "Boundary: nil when no macro is being defined."
+  (let ((defining-kbd-macro nil))
+    (should-not (cj/--modeline-macro-indicator))))
+
+;; ---------------------------- Remote Host Tag --------------------------------
+
+(ert-deftest test-modeline-config-remote-host-shows-host ()
+  "Normal: remote default-directory yields an @host tag."
+  (with-temp-buffer
+    (setq default-directory "/ssh:velox:/home/cjennings/")
+    (let ((s (cj/--modeline-remote-host)))
+      (should (stringp s))
+      (should (string-match-p "@velox" s)))))
+
+(ert-deftest test-modeline-config-remote-host-nil-when-local ()
+  "Boundary: nil for a local directory."
+  (with-temp-buffer
+    (setq default-directory "/tmp/")
+    (should-not (cj/--modeline-remote-host))))
+
+;; --------------------------- Narrowing Indicator -----------------------------
+
+(ert-deftest test-modeline-config-narrow-indicator-shows-when-narrowed ()
+  "Normal: narrowed buffer yields the Narrow tag."
+  (with-temp-buffer
+    (insert "line one\nline two\nline three\n")
+    (narrow-to-region 1 9)
+    (let ((s (cj/--modeline-narrow-indicator)))
+      (should (stringp s))
+      (should (string-match-p "Narrow" s)))))
+
+(ert-deftest test-modeline-config-narrow-indicator-nil-when-widened ()
+  "Boundary: nil when the buffer is not narrowed."
+  (with-temp-buffer
+    (insert "text")
+    (should-not (cj/--modeline-narrow-indicator))))
+
+;; --------------------------- Position / Region Info ---------------------------
+
+(ert-deftest test-modeline-config-position-info-line-column-percent ()
+  "Normal: no region yields L: C: plus a percentage-through-buffer."
+  (with-temp-buffer
+    (insert (make-string 200 ?x))
+    (goto-char (point-min))
+    (deactivate-mark)
+    (let ((s (cj/--modeline-position-info)))
+      (should (stringp s))
+      (should (string-match-p "L:" s))
+      (should (string-match-p "C:" s))
+      ;; point-based percent, %%-escaped for the mode-line construct pass
+      (should (string-match-p "%" s)))))
+
+(ert-deftest test-modeline-config-position-info-region-lines-chars ()
+  "Normal: an active region yields selection info instead of position."
+  (with-temp-buffer
+    (insert "one\ntwo\nthree\n")
+    (goto-char (point-min))
+    (push-mark (point) t t)
+    (goto-char 9)                       ; through "one\ntwo\n"
+    (let ((transient-mark-mode t))
+      (let ((s (cj/--modeline-position-info)))
+        (should (stringp s))
+        (should (string-match-p "2 lines" s))
+        (should (string-match-p "8 chars" s))))))
+
+(ert-deftest test-modeline-config-position-info-single-char-region ()
+  "Boundary: a one-char region reports 1 line, 1 char."
+  (with-temp-buffer
+    (insert "abc")
+    (goto-char 1)
+    (push-mark (point) t t)
+    (goto-char 2)
+    (let ((transient-mark-mode t))
+      (let ((s (cj/--modeline-position-info)))
+        (should (string-match-p "1 line" s))
+        (should (string-match-p "1 char" s))))))
+
+;; ------------------------------- Padding --------------------------------------
+
+(ert-deftest test-modeline-config-padding-carries-height-display ()
+  "Normal: padding space carries a display height property."
+  (let ((cj/modeline-height-factor 1.2))
+    (let ((s (cj/--modeline-padding)))
+      (should (stringp s))
+      (should (get-text-property 0 'display s)))))
+
+(ert-deftest test-modeline-config-padding-plain-at-factor-one ()
+  "Boundary: factor 1.0 (or nil) yields a plain space, no display prop."
+  (let ((cj/modeline-height-factor 1.0))
+    (let ((s (cj/--modeline-padding)))
+      (should (stringp s))
+      (should-not (get-text-property 0 'display s)))))
+
+(provide 'test-modeline-config-segments)
+;;; test-modeline-config-segments.el ends here
diff --git a/tests/test-modeline-config-vc-cache-key.el b/tests/test-modeline-config-vc-cache-key.el
index 6ba7985c..38052949 100644
--- a/tests/test-modeline-config-vc-cache-key.el
+++ b/tests/test-modeline-config-vc-cache-key.el
@@ -17,20 +17,20 @@
 (ert-deftest test-modeline-vc-cache-key-is-file-and-show-remote ()
   "Normal: the key is (FILE SHOW-REMOTE), with no per-render file-truename stat."
   (let ((cj/modeline-vc-show-remote nil))
-    (should (equal (cj/modeline-vc-cache-key "/x/y.el") '("/x/y.el" nil)))))
+    (should (equal (cj/--modeline-vc-cache-key "/x/y.el") '("/x/y.el" nil)))))
 
 (ert-deftest test-modeline-vc-cache-key-tracks-show-remote ()
   "Boundary: toggling show-remote yields a different key (separate cache entry)."
   (should-not (equal (let ((cj/modeline-vc-show-remote nil))
-                       (cj/modeline-vc-cache-key "/x/y.el"))
+                       (cj/--modeline-vc-cache-key "/x/y.el"))
                      (let ((cj/modeline-vc-show-remote t))
-                       (cj/modeline-vc-cache-key "/x/y.el")))))
+                       (cj/--modeline-vc-cache-key "/x/y.el")))))
 
 (ert-deftest test-modeline-vc-cache-key-stable-for-same-file ()
   "Boundary: the key is stable across calls for an unchanged file + show-remote."
   (let ((cj/modeline-vc-show-remote nil))
-    (should (equal (cj/modeline-vc-cache-key "/x/y.el")
-                   (cj/modeline-vc-cache-key "/x/y.el")))))
+    (should (equal (cj/--modeline-vc-cache-key "/x/y.el")
+                   (cj/--modeline-vc-cache-key "/x/y.el")))))
 
 (provide 'test-modeline-config-vc-cache-key)
 ;;; test-modeline-config-vc-cache-key.el ends here