1 files changed, 64 insertions, 0 deletions
diff --git a/tests/test-ai-vterm--displayed-claude-window.el b/tests/test-ai-vterm--displayed-claude-window.el
new file mode 100644
index 00000000..283a1b3c
--- /dev/null
+++ b/tests/test-ai-vterm--displayed-claude-window.el
@@ -0,0 +1,64 @@
+;;; test-ai-vterm--displayed-claude-window.el --- Tests for the displayed-window helper -*- lexical-binding: t; -*-
+
+;;; Commentary:
+;; The helper returns a window in the selected frame whose buffer
+;; satisfies `cj/--ai-vterm-buffer-p', or nil when no such window
+;; exists.  Used by F9 dispatch and M-F9 in-place replacement.
+
+;;; Code:
+
+(require 'ert)
+
+(add-to-list 'load-path (expand-file-name "modules" user-emacs-directory))
+(require 'ai-vterm)
+
+(defun test-ai-vterm--displayed-cleanup ()
+  "Kill any leftover claude-prefixed buffers."
+  (dolist (b (buffer-list))
+    (when (string-prefix-p "claude [" (buffer-name b))
+      (kill-buffer b))))
+
+(ert-deftest test-ai-vterm--displayed-claude-window-no-buffers-returns-nil ()
+  "Boundary: no claude buffers anywhere -> nil."
+  (test-ai-vterm--displayed-cleanup)
+  (save-window-excursion
+    (delete-other-windows)
+    (should-not (cj/--ai-vterm-displayed-claude-window))))
+
+(ert-deftest test-ai-vterm--displayed-claude-window-not-displayed-returns-nil ()
+  "Boundary: claude buffer exists but not in any window -> nil."
+  (test-ai-vterm--displayed-cleanup)
+  (let ((b1 (get-buffer-create "claude [hidden]")))
+    (unwind-protect
+        (save-window-excursion
+          (delete-other-windows)
+          (should-not (cj/--ai-vterm-displayed-claude-window)))
+      (kill-buffer b1))))
+
+(ert-deftest test-ai-vterm--displayed-claude-window-returns-window-when-displayed ()
+  "Normal: claude buffer in a window -> returns that window."
+  (test-ai-vterm--displayed-cleanup)
+  (let ((b1 (get-buffer-create "claude [shown]")))
+    (unwind-protect
+        (save-window-excursion
+          (delete-other-windows)
+          (let ((win (split-window-right)))
+            (set-window-buffer win b1)
+            (let ((result (cj/--ai-vterm-displayed-claude-window)))
+              (should (windowp result))
+              (should (eq (window-buffer result) b1)))))
+      (kill-buffer b1))))
+
+(ert-deftest test-ai-vterm--displayed-claude-window-ignores-non-claude-windows ()
+  "Boundary: only a non-claude buffer is displayed -> nil."
+  (test-ai-vterm--displayed-cleanup)
+  (let ((other (get-buffer-create "regular-displayed-buffer")))
+    (unwind-protect
+        (save-window-excursion
+          (delete-other-windows)
+          (set-window-buffer (selected-window) other)
+          (should-not (cj/--ai-vterm-displayed-claude-window)))
+      (kill-buffer other))))
+
+(provide 'test-ai-vterm--displayed-claude-window)
+;;; test-ai-vterm--displayed-claude-window.el ends here