feat(ai-term): step into detached sessions too, attaching them

The next-agent step (C-; a n / M-SPC) cycled only live agent buffers, so a detached session (alive in tmux, no Emacs buffer) was reachable only through the picker. Now the queue is every active agent, live buffer or live session, keyed on the project dir and ordered by buffer name. Stepping onto a detached one attaches it: show-or-create recreates the terminal, which reattaches the tmux session. The live-buffer swap path is unchanged. I replaced the buffer-rotation helper with a dir-based one and added an active-agent enumerator, with 10 tests.

1 files changed, 50 insertions, 0 deletions

diff --git a/tests/test-ai-term--active-agent-dirs.el b/tests/test-ai-term--active-agent-dirs.el
new file mode 100644
index 000000000..86e557b42
--- /dev/null
+++ b/tests/test-ai-term--active-agent-dirs.el
@@ -0,0 +1,50 @@
+;;; test-ai-term--active-agent-dirs.el --- Tests for cj/--ai-term-active-agent-dirs -*- lexical-binding: t; -*-
+
+;;; Commentary:
+;; The queue `cj/ai-term-next' steps through: project dirs with an active
+;; agent, which is either a live agent buffer (attached) or a live tmux session
+;; with no Emacs buffer (detached).  Folding detached sessions in is what lets
+;; the step key reach and attach a session that isn't currently on screen.
+;; Candidates / buffers / sessions are mocked so the enumeration logic is
+;; exercised without a real tmux server.
+
+;;; Code:
+
+(require 'ert)
+(require 'cl-lib)
+
+(add-to-list 'load-path (expand-file-name "modules" user-emacs-directory))
+(require 'ai-term)
+
+(ert-deftest test-ai-term--active-agent-dirs-includes-attached-and-detached ()
+  "Normal: dirs with a live buffer OR a live session are active and sorted by
+name; dirs with neither are excluded."
+  (let ((buf (get-buffer-create (cj/--ai-term-buffer-name "/p/alpha"))))
+    (unwind-protect
+        (cl-letf (((symbol-function 'cj/--ai-term-candidates)
+                   (lambda (&rest _) '("/p/alpha" "/p/beta" "/p/gamma" "/p/delta")))
+                  ((symbol-function 'cj/--ai-term-agent-buffers)
+                   (lambda (&rest _) (list buf)))
+                  ((symbol-function 'cj/--ai-term-live-tmux-sessions)
+                   (lambda (&rest _) (list (cj/--ai-term-tmux-session-name "/p/gamma")))))
+          ;; alpha attached (buffer), gamma detached (session); beta/delta neither.
+          (should (equal '("/p/alpha" "/p/gamma") (cj/--ai-term-active-agent-dirs))))
+      (kill-buffer buf))))
+
+(ert-deftest test-ai-term--active-agent-dirs-detached-only ()
+  "Normal: a dir with only a live session (no buffer) is included -- the detached case."
+  (cl-letf (((symbol-function 'cj/--ai-term-candidates) (lambda (&rest _) '("/p/solo")))
+            ((symbol-function 'cj/--ai-term-agent-buffers) (lambda (&rest _) nil))
+            ((symbol-function 'cj/--ai-term-live-tmux-sessions)
+             (lambda (&rest _) (list (cj/--ai-term-tmux-session-name "/p/solo")))))
+    (should (equal '("/p/solo") (cj/--ai-term-active-agent-dirs)))))
+
+(ert-deftest test-ai-term--active-agent-dirs-empty-when-none-active ()
+  "Boundary: no live buffers and no sessions -> an empty queue."
+  (cl-letf (((symbol-function 'cj/--ai-term-candidates) (lambda (&rest _) '("/p/a" "/p/b")))
+            ((symbol-function 'cj/--ai-term-agent-buffers) (lambda (&rest _) nil))
+            ((symbol-function 'cj/--ai-term-live-tmux-sessions) (lambda (&rest _) nil)))
+    (should (null (cj/--ai-term-active-agent-dirs)))))
+
+(provide 'test-ai-term--active-agent-dirs)
+;;; test-ai-term--active-agent-dirs.el ends here