test: add test cases for AI comment pattern matching

tests/basic/test_watch.py

@@ -0,0 +1,33 @@
+from pathlib import Path
+from aider.watch import FileWatcher
+
+def test_ai_comment_pattern():
+    # Test various AI comment patterns
+    test_comments = [
+        "# ai do something",
+        "# AI make this better", 
+        "# ai! urgent change needed",
+        "# AI! another urgent one",
+        "//ai javascript style",
+        "//AI do that thing",
+        "//ai! urgent js thing",
+        "// ai with some space",
+        "// AI with caps",
+        "// ai! with bang",
+    ]
+
+    # Non-AI comments that shouldn't match
+    non_ai_comments = [
+        "# this is not an ai comment",
+        "// this is also not an ai comment",
+        "# aider is not an ai comment",
+        "// aider is not an ai comment",
+    ]
+
+    # Test that all AI comments match
+    for comment in test_comments:
+        assert FileWatcher.ai_comment_pattern.search(comment), f"Should match: {comment}"
+
+    # Test that non-AI comments don't match
+    for comment in non_ai_comments:
+        assert not FileWatcher.ai_comment_pattern.search(comment), f"Should not match: {comment}"

tests/fixtures/watch.py

@@ -0,0 +1,19 @@
+# Regular AI comment
+# ai do something
+# AI make this better
+# ai! urgent change needed
+# AI! another urgent one
+//ai javascript style
+//AI do that thing
+//ai! urgent js thing
+// ai with some space
+// AI with caps
+// ai! with bang
+# this is not an ai comment
+// this is also not an ai comment
+# aider is not an ai comment
+// aider is not an ai comment
+
+def dummy_function():
+    # ai inside function
+    pass