Fix #209: user messages were missing from prompt.

nemoguardrails/rails/llm/llmrails.py

@@ -350,14 +350,25 @@ def _get_events_for_messages(self, messages: List[dict]):
 
         # For the rest of the messages, we transform them directly into events.
         # TODO: Move this to separate function once more types of messages are supported.
-        for msg in messages[p:]:
+        for idx in range(p, len(messages)):
+            msg = messages[idx]
             if msg["role"] == "user":
                 events.append(
                     {
                         "type": "UtteranceUserActionFinished",
                         "final_transcript": msg["content"],
                     }
                 )
+
+                # If it's not the last message, we also need to add the `UserMessage` event
+                if idx != len(messages) - 1:
+                    events.append(
+                        {
+                            "type": "UserMessage",
+                            "text": msg["content"],
+                        }
+                    )
+
             elif msg["role"] == "assistant":
                 events.append(
                     {"type": "StartUtteranceBotAction", "script": msg["content"]}

tests/test_bug_5.py

@@ -0,0 +1,66 @@
+# SPDX-FileCopyrightText: Copyright (c) 2023 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+# SPDX-License-Identifier: Apache-2.0
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from nemoguardrails import RailsConfig
+from tests.utils import TestChat
+
+config = RailsConfig.from_content(
+    """
+define user express greeting
+    "hello"
+    "hi"
+    "how are you"
+
+define bot express greeting
+    "Hey!"
+
+define flow greeting
+    user express greeting
+    bot express greeting
+""",
+    yaml_content="""
+    models:
+      - type: main
+        engine: nemollm
+        model: gpt-43b-002
+    """,
+)
+
+
+def test_1():
+    chat = TestChat(
+        config,
+        llm_completions=[
+            "  express greeting",
+        ],
+    )
+
+    rails = chat.app
+
+    messages = [
+        {"role": "user", "content": "Hi 1!"},
+        {"role": "assistant", "content": "Hi 2!"},
+        {"role": "user", "content": "Hi 3!"},
+        {"role": "assistant", "content": "Hi 4!"},
+        {"role": "user", "content": "Hi!"},
+    ]
+    new_message = rails.generate(messages=messages)
+
+    assert new_message == {"role": "assistant", "content": "Hey!"}
+
+    info = rails.explain()
+    assert len(info.llm_calls) == 1
+    assert "Hi 1!" in info.llm_calls[0].prompt
+    assert "Hi 3!" in info.llm_calls[0].prompt