fix: LLM - Exported the ChatMessage class

PiperOrigin-RevId: 544541329

Author: Ark-kun

tests/unit/aiplatform/test_language_models.py

@@ -756,6 +756,16 @@ def test_chat(self):
                     output_text="Ned likes watching movies.",
                 ),
             ],
+            message_history=[
+                preview_language_models.ChatMessage(
+                    author=preview_language_models.ChatSession.USER_AUTHOR,
+                    content="Question 1?",
+                ),
+                preview_language_models.ChatMessage(
+                    author=preview_language_models.ChatSession.MODEL_AUTHOR,
+                    content="Answer 1.",
+                ),
+            ],
             temperature=0.0,
         )
 
@@ -773,11 +783,11 @@ def test_chat(self):
             ]
             response = chat.send_message(message_text1)
             assert response.text == expected_response1
-            assert len(chat.message_history) == 2
-            assert chat.message_history[0].author == chat.USER_AUTHOR
-            assert chat.message_history[0].content == message_text1
-            assert chat.message_history[1].author == chat.MODEL_AUTHOR
-            assert chat.message_history[1].content == expected_response1
+            assert len(chat.message_history) == 4
+            assert chat.message_history[2].author == chat.USER_AUTHOR
+            assert chat.message_history[2].content == message_text1
+            assert chat.message_history[3].author == chat.MODEL_AUTHOR
+            assert chat.message_history[3].content == expected_response1
 
         gca_predict_response2 = gca_prediction_service.PredictResponse()
         gca_predict_response2.predictions.append(_TEST_CHAT_GENERATION_PREDICTION2)
@@ -793,11 +803,11 @@ def test_chat(self):
             ]
             response = chat.send_message(message_text2, temperature=0.1)
             assert response.text == expected_response2
-            assert len(chat.message_history) == 4
-            assert chat.message_history[2].author == chat.USER_AUTHOR
-            assert chat.message_history[2].content == message_text2
-            assert chat.message_history[3].author == chat.MODEL_AUTHOR
-            assert chat.message_history[3].content == expected_response2
+            assert len(chat.message_history) == 6
+            assert chat.message_history[4].author == chat.USER_AUTHOR
+            assert chat.message_history[4].content == message_text2
+            assert chat.message_history[5].author == chat.MODEL_AUTHOR
+            assert chat.message_history[5].content == expected_response2
 
         # Validating the parameters
         chat_temperature = 0.1

vertexai/preview/language_models.py

@@ -17,6 +17,7 @@
 from vertexai.language_models._language_models import (
     _PreviewTextEmbeddingModel,
     _PreviewTextGenerationModel,
+    ChatMessage,
     ChatModel,
     ChatSession,
     CodeChatModel,
@@ -31,6 +32,7 @@
 TextEmbeddingModel = _PreviewTextEmbeddingModel
 
 __all__ = [
+    "ChatMessage",
     "ChatModel",
     "ChatSession",
     "CodeChatModel",