fix: Address PR review feedback and fix pre-existing test failures

Add explicit (require 'ai-code-change) to ai-code-discussion.el and
gate TODO routing on buffer-file-name to prevent errors in unsaved
buffers. Fix claude-code multiline test by mocking MCP agent launch,
and fix capf test by adding ai-code-git require and magit-git-lines
mock to test repo macro.

Author: Kang Tu

ai-code-discussion.el

@@ -13,6 +13,7 @@
 
 (require 'ai-code-input)
 (require 'ai-code-prompt-mode)
+(require 'ai-code-change)
 
 (declare-function ai-code-read-string "ai-code-input")
 (declare-function ai-code--insert-prompt "ai-code-prompt-mode")
@@ -21,8 +22,6 @@
 (declare-function ai-code--ensure-files-directory "ai-code-prompt-mode")
 (declare-function ai-code--git-root "ai-code-file" (&optional dir))
 (declare-function ai-code--format-repo-context-info "ai-code-file")
-(declare-function ai-code--detect-todo-info "ai-code-change" (region-active))
-(declare-function ai-code-implement-todo "ai-code-change" (arg &optional default-action))
 
 (defvar ai-code--repo-context-info)
 
@@ -110,7 +109,8 @@ Argument ARG is the prefix argument."
     (let ((clipboard-context (when arg (ai-code--get-clipboard-text))))
       (ai-code--ask-question-dired clipboard-context)))
    (t
-    (let ((todo-info (ai-code--detect-todo-info (region-active-p))))
+    (let ((todo-info (when buffer-file-name
+                       (ai-code--detect-todo-info (region-active-p)))))
       (if todo-info
           (ai-code-implement-todo arg "Ask question")
         (let ((clipboard-context (when arg (ai-code--get-clipboard-text))))

test/test_ai-code-claude-code.el

@@ -25,6 +25,8 @@
               ((symbol-function 'ai-code-backends-infra--resolve-start-command)
                (lambda (&rest _args)
                  (list :command "claude")))
+              ((symbol-function 'ai-code-mcp-agent-prepare-launch)
+               (lambda (&rest _args) nil))
               ((symbol-function 'ai-code-backends-infra--toggle-or-create-session)
                (lambda (&rest args)
                  (cl-destructuring-bind

test/test_ai-code-prompt-mode.el

@@ -10,6 +10,7 @@
 
 (require 'ert)
 (require 'ai-code-prompt-mode)
+(require 'ai-code-git)
 (require 'magit)
 (require 'cl-lib)
 
@@ -36,7 +37,12 @@ and ensures everything is cleaned up afterward."
            (with-temp-file outside-file (insert "content"))
            ;; Execute test body with mocks
            (cl-letf (((symbol-function 'magit-toplevel) (lambda (&optional dir) git-root))
-                     ((symbol-function 'ai-code--git-root) (lambda (&optional dir) git-root)))
+                     ((symbol-function 'ai-code--git-root) (lambda (&optional dir) git-root))
+                     ((symbol-function 'magit-git-lines)
+                      (lambda (&rest _args)
+                        (let ((default-directory git-root))
+                          (mapcar (lambda (f) (file-relative-name f git-root))
+                                  (directory-files-recursively git-root ""))))))
              ,@body))
        ;; Teardown: Clean up dummy files and directories
        (when (file-exists-p mock-file-in-repo) (delete-file mock-file-in-repo))