test: specify Magit hunk workflows for existing AI commands

Author: tninja

test/test_ai-code-magit.el

@@ -0,0 +1,222 @@
+;;; test_ai-code-magit.el --- Magit hunk workflow tests -*- lexical-binding: t; -*-
+
+;; SPDX-License-Identifier: Apache-2.0
+
+;;; Commentary:
+;; Exercise real Magit section objects, without invoking an agent.
+
+;;; Code:
+
+(require 'ert)
+(require 'cl-lib)
+(require 'magit-diff)
+(require 'ai-code-change)
+(require 'ai-code-discussion)
+(require 'ai-code-agile)
+(require 'ai-code-file)
+(require 'ai-code-magit nil t)
+
+(defmacro ai-code-magit-test--with-diff (&rest body)
+  "Build a real Magit section tree and evaluate BODY at its first hunk."
+  (declare (indent 0) (debug t))
+  `(with-temp-buffer
+     (setq major-mode 'magit-status-mode)
+     (let ((magit-section-set-visibility-hook nil)
+           (magit-section-insert-hook nil)
+           (transient-mark-mode t)
+           first-hunk second-hunk file-section)
+       (magit-insert-section (root)
+         (magit-insert-section (unstaged)
+           (magit-insert-heading "Unstaged changes")
+           (setq file-section
+                 (magit-insert-section (file "src/example.el" nil
+                                       :source "src/old.el"
+                                       :header "diff --git a/src/old.el b/src/example.el\n--- a/src/old.el\n+++ b/src/example.el\n")
+                   (magit-insert-heading "modified src/example.el")
+                   (setq first-hunk
+                         (magit-insert-section (hunk '(nil (1 1) (1 1)))
+                           (magit-insert-heading "@@ -1 +1 @@")
+                           (insert "-old-value\n+new-value\n")))
+                   (setq second-hunk
+                         (magit-insert-section (hunk '(nil (20 1) (20 1)))
+                           (magit-insert-heading "@@ -20 +20 @@")
+                           (insert "-old-other\n+new-other\n")))))))
+       (goto-char (oref first-hunk start))
+       (cl-letf (((symbol-function 'magit-toplevel)
+                  (lambda (&optional _) "/tmp/ai-code-magit-project/"))
+                 ((symbol-function 'ai-code--git-root)
+                  (lambda (&optional _) "/tmp/ai-code-magit-project/"))
+                 ((symbol-function 'magit-rev-parse)
+                  (lambda (&rest _) "0123456789abcdef")))
+         ,@body))))
+
+(ert-deftest ai-code-magit-context-current-hunk ()
+  "Capture one hunk with paths, provenance, and no neighboring changes."
+  (ai-code-magit-test--with-diff
+    (let* ((context (ai-code-magit-context))
+           (text (plist-get context :text)))
+      (should (equal (plist-get context :root) "/tmp/ai-code-magit-project/"))
+      (should (eq (plist-get context :type) 'unstaged))
+      (should (string-match-p "index -> working tree" text))
+      (should (string-match-p "0123456789abcdef" text))
+      (should (string-match-p "src/old.el" text))
+      (should (string-match-p "src/example.el" text))
+      (should (string-match-p "new-value" text))
+      (should-not (string-match-p "new-other" text)))))
+
+(ert-deftest ai-code-magit-context-multiple-hunks ()
+  "Use Magit's sibling selection, in display order."
+  (ai-code-magit-test--with-diff
+    (set-mark (oref first-hunk start))
+    (goto-char (oref second-hunk start))
+    (setq mark-active t)
+    (let ((text (plist-get (ai-code-magit-context) :text)))
+      (should (string-match-p "new-value" text))
+      (should (string-match-p "new-other" text))
+      (should (< (string-match "new-value" text)
+                 (string-match "new-other" text))))))
+
+(ert-deftest ai-code-magit-context-partial-hunk ()
+  "Keep the complete hunk but identify the selected text separately."
+  (ai-code-magit-test--with-diff
+    (goto-char (oref first-hunk content))
+    (forward-line 1)
+    (set-mark (point))
+    (end-of-line)
+    (setq mark-active t)
+    (let ((text (plist-get (ai-code-magit-context) :text)))
+      (should (string-match-p "Selected excerpt (focus only" text))
+      (should (string-match-p "old-value" text))
+      (should (string-match-p "new-value" text))
+      (should-not (string-match-p "new-other" text)))))
+
+(ert-deftest ai-code-magit-context-staged ()
+  "Never describe the index as the working-tree source."
+  (ai-code-magit-test--with-diff
+    (oset (oref file-section parent) type 'staged)
+    (let ((context (ai-code-magit-context)))
+      (should (eq (plist-get context :type) 'staged))
+      (should (string-match-p "HEAD -> index" (plist-get context :text))))))
+
+(ert-deftest ai-code-magit-context-history ()
+  "Preserve a revision buffer's ref and classify it as historical."
+  (ai-code-magit-test--with-diff
+    (setq major-mode 'magit-revision-mode)
+    (setq-local magit-buffer-refname "abc123")
+    (let ((context (ai-code-magit-context)))
+      (should (eq (plist-get context :type) 'committed))
+      (should (string-match-p "abc123" (plist-get context :text))))))
+
+(ert-deftest ai-code-magit-context-rejects-non-hunk ()
+  "Do not silently turn a file heading into a whole-file request."
+  (ai-code-magit-test--with-diff
+    (goto-char (oref file-section start))
+    (should-error (ai-code-magit-context) :type 'user-error)))
+
+(ert-deftest ai-code-magit-context-rejects-invalid-selection ()
+  "Do not silently drop selected text spanning incompatible sections."
+  (ai-code-magit-test--with-diff
+    (set-mark (oref first-hunk content))
+    (goto-char (oref second-hunk content))
+    (setq mark-active t)
+    (should-error (ai-code-magit-context) :type 'user-error)))
+
+(ert-deftest ai-code-magit-context-rejects-pseudo-hunk ()
+  "A chmod or rename pseudo-hunk is not a textual patch."
+  (ai-code-magit-test--with-diff
+    (oset first-hunk value '(chmod))
+    (should-error (ai-code-magit-context) :type 'user-error)))
+
+(defun ai-code-magit-test--prompt (command &optional argument)
+  "Capture the prompt generated by COMMAND with ARGUMENT."
+  (let (result)
+    (cl-letf (((symbol-function 'ai-code--insert-prompt)
+               (lambda (text) (setq result text)))
+              ((symbol-function 'ai-code-read-string)
+               (lambda (&rest _) "Keep compatibility"))
+              ((symbol-function 'ai-code--format-repo-context-info)
+               (lambda () "Existing task context"))
+              ((symbol-function 'ai-code--get-clipboard-text)
+               (lambda () "Clipboard constraint")))
+      (if (memq command '(ai-code-ask-question ai-code-code-change))
+          (funcall command argument)
+        (funcall command)))
+    result))
+
+(ert-deftest ai-code-magit-explain-hunk-read-only ()
+  "Explain changes, not merely the resulting source."
+  (ai-code-magit-test--with-diff
+    (let ((prompt (ai-code-magit-test--prompt #'ai-code-explain)))
+      (should (string-match-p "behavior" prompt))
+      (should (string-match-p "new-value" prompt))
+      (should (eq (ai-code--simple-classify-prompt-code-change prompt)
+                  'non-code-change)))))
+
+(ert-deftest ai-code-magit-ask-question-hunk-read-only ()
+  "Questions preserve user text, clipboard and existing task context."
+  (ai-code-magit-test--with-diff
+    (let ((prompt (ai-code-magit-test--prompt #'ai-code-ask-question t)))
+      (dolist (text '("Keep compatibility" "Clipboard constraint"
+                      "Existing task context" "new-value"))
+        (should (string-match-p text prompt)))
+      (should (eq (ai-code--simple-classify-prompt-code-change prompt)
+                  'non-code-change)))))
+
+(ert-deftest ai-code-magit-change-hunk-rereads-source ()
+  "Change feedback targets current source without staging or committing."
+  (ai-code-magit-test--with-diff
+    (let ((prompt (ai-code-magit-test--prompt #'ai-code-code-change t)))
+      (dolist (text '("Keep compatibility" "Clipboard constraint"
+                      "Re-read" "Do not stage" "new-value"))
+        (should (string-match-p text prompt)))
+      (should (eq (ai-code--simple-classify-prompt-code-change prompt)
+                  'code-change)))))
+
+(ert-deftest ai-code-magit-tests-add-coverage-without-fake-red ()
+  "Test an existing change without forcing Red/Green or source fixes."
+  (ai-code-magit-test--with-diff
+    (let ((prompt (ai-code-magit-test--prompt #'ai-code-tdd-cycle)))
+      (dolist (text '("existing tests" "Run" "Do not modify production code"
+                      "Do not claim a test-first" "new-value"))
+        (should (string-match-p text prompt))))))
+
+(ert-deftest ai-code-magit-tests-disable-conflicting-auto-tdd ()
+  "The hunk test request must not append a strict implementation TDD loop."
+  (ai-code-magit-test--with-diff
+    (let ((ai-code-auto-test-type 'tdd)
+          (seen 'unset))
+      (cl-letf (((symbol-function 'ai-code--insert-prompt)
+                 (lambda (_) (setq seen ai-code-auto-test-type))))
+        (ai-code-tdd-cycle))
+      (should-not seen)
+      (should (eq ai-code-auto-test-type 'tdd)))))
+
+(ert-deftest ai-code-magit-history-write-commands-refuse ()
+  "Historical diffs are references, not current editing targets."
+  (ai-code-magit-test--with-diff
+    (setq major-mode 'magit-revision-mode)
+    (dolist (command '(ai-code-code-change ai-code-tdd-cycle))
+      (should-error (ai-code-magit-test--prompt command) :type 'user-error))))
+
+(ert-deftest ai-code-magit-add-context-captures-hunk-before-prompting ()
+  "Store the actual snapshot, not just a filename or the Magit buffer."
+  (ai-code-magit-test--with-diff
+    (let ((ai-code--repo-context-info (make-hash-table :test 'equal)))
+      (ai-code-add-context)
+      (let ((entry (car (gethash "/tmp/ai-code-magit-project/"
+                                 ai-code--repo-context-info))))
+        (should (string-match-p "new-value" entry))
+        (should (string-match-p "snapshot" entry))
+        (should-not (string-match-p "new-other" entry))))))
+
+(ert-deftest ai-code-magit-copy-context-copies-patch-not-branch ()
+  "The context menu's copy action should include the selected patch."
+  (ai-code-magit-test--with-diff
+    (let (copied)
+      (cl-letf (((symbol-function 'kill-new)
+                 (lambda (text &rest _) (setq copied text))))
+        (ai-code-copy-buffer-file-name-to-clipboard))
+      (should (string-match-p "new-value" copied)))))
+
+(provide 'test_ai-code-magit)
+;;; test_ai-code-magit.el ends here