Feat: Pre-fill derive topics from the scope at point; add learning tests to the TDD menu

ai-code-agile.el

@@ -28,6 +28,7 @@
 (declare-function ai-code--scope-context-for-region "ai-code-utils" (beg end))
 (declare-function ai-code--format-scope-context "ai-code-utils" (context))
 (declare-function ai-code--git-root "ai-code-utils" (&optional dir))
+(declare-function ai-code-derive-topic-unit-tests "ai-code-doc" ())
 (declare-function dired-current-directory "dired" ())
 (declare-function dired-get-filename "dired" (&optional localp no-error-if-not-filep))
 (declare-function dired-get-marked-files "dired"
@@ -1001,6 +1002,7 @@ Works with both source code and test files that have been added to ai-code."
   (if (derived-mode-p 'magit-mode)
       (ai-code-magit-prompt 'tests)
     ;; DONE: use-write-test-stage should also support selected region. If there is selected region, we can use it as the context for writing a test. If there is no selected region, we can use the current function name as the context for writing a test.
+    ;; DONE: ai-code-derive-topic-unit-tests should be added as the last option of C-c a t, purpose is to derive the test code as tutorial and learning material for the user for given topic.
     (let* ((region-active (region-active-p))
            (scope-context
             (if region-active
@@ -1033,7 +1035,8 @@ Works with both source code and test files that have been added to ai-code."
                                "2. Green (Make test pass)"
                                "3. Blue (Refactor, improve code quality)"
                                "4. Red + Green (One prompt)"
-                               "5. Red + Green + Blue (One prompt)")
+                               "5. Red + Green + Blue (One prompt)"
+                               "6. Learning tests (Derive unit tests as a tutorial for a topic)")
                          nil t))
            (stage-num (string-to-number (substring cycle-stage 0 1))))
       (cond
@@ -1051,7 +1054,9 @@ Works with both source code and test files that have been added to ai-code."
        ;; Red + Green combined in one prompt
        ((= stage-num 4) (ai-code--tdd-red-green-stage function-name))
        ;; Red + Green + Blue combined in one prompt
-       ((= stage-num 5) (ai-code--tdd-red-green-blue-stage function-name))))))
+       ((= stage-num 5) (ai-code--tdd-red-green-blue-stage function-name))
+       ;; Learning tests - derive unit tests as a tutorial for a topic
+       ((= stage-num 6) (ai-code-derive-topic-unit-tests))))))
 
 (provide 'ai-code-agile)
 

ai-code-doc.el

@@ -71,12 +71,31 @@ Default value is English."
   "Prompt for the language and append it to BASE-PROMPT."
   (concat base-prompt (format "\nGenerate the document in %s." (ai-code--read-document-language))))
 
+(defun ai-code--topic-at-point ()
+  "Return the function or class at point as a topic, or nil.
+Only `prog-mode' buffers offer one, formatted as \"Service.run
+\(src/Service.java)\" with the file relative to the repository root.
+The file part is omitted when the buffer visits no file."
+  (when (derived-mode-p 'prog-mode)
+    (when-let* ((scope (ai-code--current-qualified-scope-name)))
+      (if buffer-file-name
+          (format "%s (%s)" scope
+                  (file-relative-name buffer-file-name (ai-code--git-root)))
+        scope))))
+
 (defun ai-code--read-document-topic ()
   "Ask which topic the document should cover.
-Return nil for an empty answer, which means the whole repository."
-  (let ((topic (string-trim
-                (read-string "Document topic (empty for whole repo): "))))
-    (unless (string-empty-p topic) topic)))
+Return nil for an empty answer, which means the whole repository.
+When `ai-code--topic-at-point' offers a topic, first ask whether to scope
+the document to it: declining means the whole repository, and accepting
+pre-fills the topic for editing."
+  (let ((at-point (ai-code--topic-at-point)))
+    (when (or (null at-point)
+              (y-or-n-p (format "Scope document to \"%s\"? " at-point)))
+      (let ((topic (string-trim
+                    (read-string "Document topic (empty for whole repo): "
+                                 at-point))))
+        (unless (string-empty-p topic) topic)))))
 
 (defun ai-code--topic-file-name (file-name topic)
   "Return FILE-NAME with a slug and stable digest of TOPIC in its base name.
@@ -390,8 +409,10 @@ selects how code references are linked."
 (defun ai-code--read-unit-test-topic ()
   "Read the topic the derived unit tests must explain.
 An empty topic leaves the backend nothing to teach, so it is rejected
-instead of falling back to the whole repository."
-  (let ((topic (string-trim (read-string "Unit test topic: "))))
+instead of falling back to the whole repository.  The topic is pre-filled
+from `ai-code--topic-at-point'."
+  (let ((topic (string-trim (read-string "Unit test topic: "
+                                         (ai-code--topic-at-point)))))
     (if (string-empty-p topic)
         (user-error "A topic is required to derive unit tests")
       topic)))
@@ -589,6 +610,7 @@ not already exist, so the backend has a concrete document to create or update."
 Unlike the other derivation commands this one produces test code beside
 the repository's own tests, so a topic is required and no Org document is
 created."
+  ;; DONE: If the current buffer is a prog-mode derived buffer (eg. java-mode, or java-ts-mode), we could pre-fill the topic with context under cursor, eg. a function, or a class.
   (interactive)
   (let* ((git-root (or (ai-code--git-root)
                        (user-error "Not inside a Git repository")))

test/test_ai-code-agile.el

@@ -164,6 +164,23 @@
         (ai-code-tdd-cycle)
         (should (equal called-function-name "my-function"))))))
 
+(ert-deftest ai-code-test-tdd-cycle-last-choice-derives-learning-tests ()
+  "Verify the last TDD stage derives learning unit tests for a topic."
+  (with-temp-buffer
+    (emacs-lisp-mode)
+    (let (captured-choices called)
+      (cl-letf (((symbol-function 'ai-code--tdd-source-function-context-p) (lambda (_) nil))
+                ((symbol-function 'completing-read)
+                 (lambda (_prompt collection &rest _)
+                   (setq captured-choices collection)
+                   (car (last collection))))
+                ((symbol-function 'ai-code-derive-topic-unit-tests)
+                 (lambda () (setq called t))))
+        (ai-code-tdd-cycle)
+        (should (equal (car (last captured-choices))
+                       "6. Learning tests (Derive unit tests as a tutorial for a topic)"))
+        (should called)))))
+
 (ert-deftest ai-code-test-run-test-always-delegates-to-ai-assisted-runner ()
   "Verify `ai-code-run-test' always delegates to the AI-assisted test runner."
   (dolist (mode-setup '(emacs-lisp-mode

test/test_ai-code-doc.el

@@ -741,6 +741,69 @@ corrupted."
              (lambda (&optional _dir) nil)))
     (should-error (ai-code-derive-topic-unit-tests) :type 'user-error)))
 
+(ert-deftest ai-code-test-read-document-topic-offers-scope-at-point ()
+  "A `prog-mode' buffer offers the scope at point with its repo-relative file.
+Accepting pre-fills the editable topic; declining means the whole
+repository without asking for a topic."
+  (ai-code-file-with-test-env
+   (with-temp-buffer
+     (prog-mode)
+     (setq buffer-file-name (expand-file-name "src/Service.java" default-directory))
+     (let ((answer t)
+           asked
+           initial-input)
+       (cl-letf (((symbol-function 'ai-code--git-root)
+                  (lambda (&optional _dir) default-directory))
+                 ((symbol-function 'ai-code--current-qualified-scope-name)
+                  (lambda () "Service.run"))
+                 ((symbol-function 'y-or-n-p)
+                  (lambda (prompt) (setq asked prompt) answer))
+                 ((symbol-function 'read-string)
+                  (lambda (_prompt &optional initial &rest _)
+                    (setq initial-input initial)
+                    (concat initial " retry"))))
+         (should (equal (ai-code--read-document-topic)
+                        "Service.run (src/Service.java) retry"))
+         (should (string-match-p (regexp-quote "\"Service.run (src/Service.java)\"")
+                                 asked))
+         (should (equal initial-input "Service.run (src/Service.java)"))
+         (setq answer nil
+               initial-input 'unread)
+         (should-not (ai-code--read-document-topic))
+         (should (eq initial-input 'unread)))))))
+
+(ert-deftest ai-code-test-read-document-topic-offers-nothing-outside-prog-mode ()
+  "Outside `prog-mode' the topic is asked blank, without a y/n question."
+  (with-temp-buffer
+    (let ((initial-input 'unread))
+      (cl-letf (((symbol-function 'ai-code--current-qualified-scope-name)
+                 (lambda () "Service.run"))
+                ((symbol-function 'y-or-n-p)
+                 (lambda (&rest _) (error "Unexpected y-or-n-p")))
+                ((symbol-function 'read-string)
+                 (lambda (_prompt &optional initial &rest _)
+                   (setq initial-input initial)
+                   "")))
+        (should-not (ai-code--read-document-topic))
+        (should-not initial-input)))))
+
+(ert-deftest ai-code-test-read-unit-test-topic-prefills-scope-at-point ()
+  "The required unit test topic is pre-filled without a y/n question.
+A buffer that visits no file offers the scope name alone."
+  (with-temp-buffer
+    (prog-mode)
+    (let (initial-input)
+      (cl-letf (((symbol-function 'ai-code--current-qualified-scope-name)
+                 (lambda () "Service"))
+                ((symbol-function 'y-or-n-p)
+                 (lambda (&rest _) (error "Unexpected y-or-n-p")))
+                ((symbol-function 'read-string)
+                 (lambda (_prompt &optional initial &rest _)
+                   (setq initial-input initial)
+                   initial)))
+        (should (equal (ai-code--read-unit-test-topic) "Service"))
+        (should (equal initial-input "Service"))))))
+
 (provide 'test_ai-code-doc)
 ;;; test_ai-code-doc.el ends here
 ;;; test_ai-code-doc.el ends here