feat(ai-vterm): order the project picker by most-recently-used

The picker's active group (projects with a live tmux session) used to sort alphabetically. It now leads with projects opened this session, most-recent first, then the rest of the active group alpha, then the no-session group alpha. An in-session list (`cj/--ai-vterm-mru'), pushed to the front by `cj/--ai-vterm-show-or-create' on every open, drives the order. An empty list reproduces the old alphabetical behavior.

I also pulled in a fix: `cj/--ai-vterm-tmux-session-name' now sanitizes `.' and `:' in the basename to `_'. tmux disallows those chars in session names and silently rewrites them, so `.emacs.d' really runs in session `aiv-_emacs_d', not `aiv-.emacs.d'. The computed name never matched, so `.emacs.d' was wrongly treated as having no session and landed in the no-session picker group. (A crash-recovery would also spawn a duplicate instead of reattaching.) Sanitizing the same way tmux does keeps the names in sync.

4 files changed, 94 insertions, 10 deletions

diff --git a/tests/test-ai-vterm--record-mru.el b/tests/test-ai-vterm--record-mru.el
new file mode 100644
index 00000000..16db4eea
--- /dev/null
+++ b/tests/test-ai-vterm--record-mru.el
@@ -0,0 +1,48 @@
+;;; test-ai-vterm--record-mru.el --- Tests for the AI-vterm project MRU list -*- lexical-binding: t; -*-
+
+;;; Commentary:
+;; `cj/--ai-vterm-record-mru' tracks which project dirs have been opened via
+;; the launcher this session, most-recently-opened first, so the picker can
+;; surface recently-used projects at the top of the active-sessions group.
+;; `cj/--ai-vterm-mru-rank' reports a dir's position in that list (or nil).
+
+;;; Code:
+
+(require 'ert)
+
+(add-to-list 'load-path (expand-file-name "modules" user-emacs-directory))
+(require 'ai-vterm)
+
+(ert-deftest test-ai-vterm--record-mru-pushes-to-front ()
+  "Normal: a freshly recorded dir leads the list, newest first."
+  (let ((cj/--ai-vterm-mru nil))
+    (cj/--ai-vterm-record-mru "/c/alpha")
+    (cj/--ai-vterm-record-mru "/c/beta")
+    (should (equal cj/--ai-vterm-mru '("/c/beta" "/c/alpha")))))
+
+(ert-deftest test-ai-vterm--record-mru-dedups-and-moves-to-front ()
+  "Normal: re-recording a dir moves it to the front with no duplicate."
+  (let ((cj/--ai-vterm-mru nil))
+    (cj/--ai-vterm-record-mru "/c/alpha")
+    (cj/--ai-vterm-record-mru "/c/beta")
+    (cj/--ai-vterm-record-mru "/c/alpha")
+    (should (equal cj/--ai-vterm-mru '("/c/alpha" "/c/beta")))))
+
+(ert-deftest test-ai-vterm--record-mru-normalizes-trailing-slash ()
+  "Boundary: `/c/foo' and `/c/foo/' are the same MRU entry."
+  (let ((cj/--ai-vterm-mru nil))
+    (cj/--ai-vterm-record-mru "/c/foo/")
+    (cj/--ai-vterm-record-mru "/c/foo")
+    (should (equal cj/--ai-vterm-mru '("/c/foo")))))
+
+(ert-deftest test-ai-vterm--mru-rank-returns-index-or-nil ()
+  "Normal/Boundary: rank is the list position; nil when the dir isn't there;
+the lookup normalizes a trailing slash the same way `record-mru' does."
+  (let ((cj/--ai-vterm-mru '("/c/beta" "/c/alpha")))
+    (should (= 0 (cj/--ai-vterm-mru-rank "/c/beta")))
+    (should (= 1 (cj/--ai-vterm-mru-rank "/c/alpha")))
+    (should (= 0 (cj/--ai-vterm-mru-rank "/c/beta/")))
+    (should-not (cj/--ai-vterm-mru-rank "/c/gamma"))))
+
+(provide 'test-ai-vterm--record-mru)
+;;; test-ai-vterm--record-mru.el ends here
diff --git a/tests/test-ai-vterm--show-or-create.el b/tests/test-ai-vterm--show-or-create.el
index 0a3dbde5..01083f84 100644
--- a/tests/test-ai-vterm--show-or-create.el
+++ b/tests/test-ai-vterm--show-or-create.el
@@ -57,8 +57,10 @@ VARS is a plist of capture variable names: :calls, :strings, :returns,
     (kill-buffer name)))
 
 (ert-deftest test-ai-vterm--show-or-create-creates-when-buffer-missing ()
-  "Normal: no existing buffer -> vterm called once, launch cmd sent."
-  (let ((name "agent [normal-create-test]"))
+  "Normal: no existing buffer -> vterm called once, launch cmd sent, the
+project recorded at the front of the MRU list."
+  (let ((name "agent [normal-create-test]")
+        (cj/--ai-vterm-mru nil))
     (test-ai-vterm--cleanup name)
     (unwind-protect
         (test-ai-vterm--with-mock-vterm (:calls calls :strings strings
@@ -68,7 +70,8 @@ VARS is a plist of capture variable names: :calls, :strings, :returns,
           (should (equal strings
                          (list (cj/--ai-vterm-launch-command "/tmp/some-project"))))
           (should (= returns 1))
-          (should (equal ddir "/tmp/some-project")))
+          (should (equal ddir "/tmp/some-project"))
+          (should (equal (car cj/--ai-vterm-mru) "/tmp/some-project")))
       (test-ai-vterm--cleanup name))))
 
 (ert-deftest test-ai-vterm--show-or-create-displays-existing-when-process-live ()
diff --git a/tests/test-ai-vterm--sort-candidates.el b/tests/test-ai-vterm--sort-candidates.el
index 5e3d760a..26953604 100644
--- a/tests/test-ai-vterm--sort-candidates.el
+++ b/tests/test-ai-vterm--sort-candidates.el
@@ -3,8 +3,10 @@
 ;;; Commentary:
 ;; The project picker lists candidates with a live tmux session first
 ;; (so an agent that survived an Emacs crash is easy to get back to),
-;; then everything else.  Within each group the order is alphabetical
-;; by abbreviated path.
+;; then everything else.  Within the active group, projects opened this
+;; session (`cj/--ai-vterm-mru') lead, most-recent first; the rest of the
+;; active group, and the whole no-session group, sort alphabetically by
+;; abbreviated path.  With an empty MRU it's just active-first-then-alpha.
 
 ;;; Code:
 
@@ -40,6 +42,27 @@
   "Boundary: no candidates -> nil."
   (should (null (cj/--ai-vterm-sort-candidates nil '("aiv-foo")))))
 
+(ert-deftest test-ai-vterm--sort-candidates-active-group-mru-first ()
+  "Normal: within the active group, recently-opened projects lead in MRU
+order; active dirs not opened this session fall after them alpha; the
+no-session group trails, alpha."
+  (let ((cj/ai-vterm-tmux-session-prefix "aiv-")
+        (cj/--ai-vterm-mru '("/c/baz" "/c/foo")))
+    (should (equal (cj/--ai-vterm-sort-candidates
+                    '("/c/foo" "/c/bar" "/c/baz" "/c/qux")
+                    '("aiv-foo" "aiv-bar" "aiv-baz"))
+                   '("/c/baz" "/c/foo" "/c/bar" "/c/qux")))))
+
+(ert-deftest test-ai-vterm--sort-candidates-mru-does-not-bump-inactive ()
+  "Boundary: an MRU dir whose tmux session has died sorts alpha in the
+no-session group, not at the top."
+  (let ((cj/ai-vterm-tmux-session-prefix "aiv-")
+        (cj/--ai-vterm-mru '("/c/zed")))
+    (should (equal (cj/--ai-vterm-sort-candidates
+                    '("/c/foo" "/c/zed" "/c/bar")
+                    '("aiv-foo"))
+                   '("/c/foo" "/c/bar" "/c/zed")))))
+
 (ert-deftest test-ai-vterm--session-active-p-matches-by-derived-name ()
   "Normal: a dir is active when its derived session name is in the set."
   (let ((cj/ai-vterm-tmux-session-prefix "aiv-"))
diff --git a/tests/test-ai-vterm--tmux-session-name.el b/tests/test-ai-vterm--tmux-session-name.el
index 8d9220eb..073dc312 100644
--- a/tests/test-ai-vterm--tmux-session-name.el
+++ b/tests/test-ai-vterm--tmux-session-name.el
@@ -5,8 +5,10 @@
 ;; the project's basename, so reopening the agent on the same project (e.g.
 ;; after an Emacs crash) reattaches to the same tmux session rather than
 ;; spawning a new one -- and the prefix lets `tmux ls' output be filtered
-;; down to AI-vterm's own sessions.  Whitespace in the basename becomes
-;; hyphens so the name is safe to pass on a tmux command line.
+;; down to AI-vterm's own sessions.  The basename is sanitized to a form
+;; tmux won't re-mangle: runs of whitespace become hyphens, and `.' / `:'
+;; (which tmux disallows in session names and silently rewrites to `_')
+;; become `_' up front so the computed name matches the real session.
 
 ;;; Code:
 
@@ -27,11 +29,19 @@
     (should (equal (cj/--ai-vterm-tmux-session-name "/home/cjennings/projects/foo/")
                    "aiv-foo"))))
 
-(ert-deftest test-ai-vterm--tmux-session-name-dot-prefix-dir ()
-  "Boundary: dot-prefix dirs preserve the dot (tmux accepts dots)."
+(ert-deftest test-ai-vterm--tmux-session-name-dots-become-underscores ()
+  "Boundary: tmux disallows `.' in session names and rewrites it to `_',
+so the basename's dots are sanitized to `_' up front -- `.emacs.d' must
+yield `aiv-_emacs_d', matching the session tmux actually creates."
   (let ((cj/ai-vterm-tmux-session-prefix "aiv-"))
     (should (equal (cj/--ai-vterm-tmux-session-name "/home/cjennings/.emacs.d")
-                   "aiv-.emacs.d"))))
+                   "aiv-_emacs_d"))))
+
+(ert-deftest test-ai-vterm--tmux-session-name-colon-becomes-underscore ()
+  "Boundary: `:' is also disallowed by tmux in session names -> `_'."
+  (let ((cj/ai-vterm-tmux-session-prefix "aiv-"))
+    (should (equal (cj/--ai-vterm-tmux-session-name "/tmp/a:b")
+                   "aiv-a_b"))))
 
 (ert-deftest test-ai-vterm--tmux-session-name-space-becomes-hyphen ()
   "Boundary: a space in the basename is replaced with a hyphen."