Fix IndexError when collating chat history (Azure-Samples#195)

* Fix IndexError when collating chat history

This fixes a bug which causes the exception:
```
ERROR:root:Exception in /api/conversation/custom | list index out of range
Traceback (most recent call last):
  File "/workspaces/chat-with-your-data-solution-accelerator/code/app/app.py", line 283, in conversation_custom
    chat_history.append((user_assistant_messages[i]['content'],user_assistant_messages[i+1]['content']))
```

This is caused when there has been an error providing a response, and
the latest message in the history is from a user, rather than the
assitant. Our code assumes a user message is always followed by an
assistant message.

This change removes that assumption and explitely retreives the role for
each message when collating the chat history.

Required by Azure-Samples#114

* Add python formatter to dev container

* Add tests for conversation custom

- Extract some elements to dedicated function to allow mocking

* Switch to black formatter to align with precommit hook

* Add test to cover error scenario when message index is out of range

* Add dependencies required for running app tests

---------

Co-authored-by: Ross Smith <ross-p-smith@users.noreply.github.com>

.devcontainer/devcontainer.json

@@ -23,6 +23,7 @@
 				"ms-azuretools.vscode-bicep",
 				"ms-azuretools.vscode-docker",
 				"ms-python.python",
+				"ms-python.black-formatter",
 				"ms-python.vscode-pylance",
 				"ms-vscode.vscode-node-azure-pack",
 				"TeamsDevApp.ms-teams-vscode-extension"

.github/workflows/unittests.yml

@@ -20,6 +20,6 @@ jobs:
             architecture: x64
         - name: Install dependencies
           run: |
-            pip install -r code/requirements.txt -r code/dev-requirements.txt
+            pip install -r code/requirements.txt -r code/dev-requirements.txt -r code/app/requirements.txt
         - name: Run Python tests
           run: python -m pytest --rootdir=code -m "not azure"

code/app/app.py

@@ -313,11 +313,21 @@ def conversation_azure_byod():
         )
 
 
-@app.route("/api/conversation/custom", methods=["GET", "POST"])
-def conversation_custom():
+def get_message_orchestrator():
     from utilities.helpers.OrchestratorHelper import Orchestrator
 
-    message_orchestrator = Orchestrator()
+    return Orchestrator()
+
+
+def get_orchestrator_config():
+    from utilities.helpers.ConfigHelper import ConfigHelper
+
+    return ConfigHelper.get_active_config_or_default().orchestrator
+
+
+@app.route("/api/conversation/custom", methods=["GET", "POST"])
+def conversation_custom():
+    message_orchestrator = get_message_orchestrator()
 
     try:
         user_message = request.json["messages"][-1]["content"]
@@ -328,22 +338,12 @@ def conversation_custom():
                 request.json["messages"][0:-1],
             )
         )
-        chat_history = []
-        for i, k in enumerate(user_assistant_messages):
-            if i % 2 == 0:
-                chat_history.append(
-                    (
-                        user_assistant_messages[i]["content"],
-                        user_assistant_messages[i + 1]["content"],
-                    )
-                )
-        from utilities.helpers.ConfigHelper import ConfigHelper
 
         messages = message_orchestrator.handle_message(
             user_message=user_message,
-            chat_history=chat_history,
+            chat_history=user_assistant_messages,
             conversation_id=conversation_id,
-            orchestrator=ConfigHelper.get_active_config_or_default().orchestrator,
+            orchestrator=get_orchestrator_config(),
         )
 
         response_obj = {

code/utilities/orchestrator/LangChainAgent.py

@@ -89,8 +89,10 @@ def orchestrate(
             memory_key="chat_history", return_messages=True
         )
         for message in chat_history:
-            memory.chat_memory.add_user_message(message[0])
-            memory.chat_memory.add_ai_message(message[1])
+            if message["role"] == "user":
+                memory.chat_memory.add_user_message(message["content"])
+            elif message["role"] == "assistant":
+                memory.chat_memory.add_ai_message(message["content"])
         # Define Agent and Agent Chain
         llm_chain = LLMChain(llm=llm_helper.get_llm(), prompt=prompt)
         agent = ZeroShotAgent(llm_chain=llm_chain, tools=self.tools, verbose=True)

code/utilities/orchestrator/OpenAIFunctions.py

@@ -81,8 +81,7 @@ def orchestrate(
         # Create conversation history
         messages = [{"role": "system", "content": system_message}]
         for message in chat_history:
-            messages.append({"role": "user", "content": message[0]})
-            messages.append({"role": "assistant", "content": message[1]})
+            messages.append({"role": message["role"], "content": message["content"]})
         messages.append({"role": "user", "content": user_message})
 
         result = llm_helper.get_chat_completion_with_functions(

tests/test_app.py

@@ -0,0 +1,161 @@
+import os
+
+from unittest.mock import Mock
+from unittest.mock import patch
+
+from code.app.app import app
+
+
+class TestConfig:
+    def test_returns_correct_config(self):
+        response = app.test_client().get("/api/config")
+
+        assert response.status_code == 200
+        assert response.json == {"azureSpeechKey": None, "azureSpeechRegion": None}
+
+
+class TestCoversationCustom:
+    def setup_method(self):
+        self.orchestrator_config = {"strategy": "langchain"}
+        self.messages = [
+            {
+                "content": '{"citations": [], "intent": "A question?"}',
+                "end_turn": False,
+                "role": "tool",
+            },
+            {"content": "An answer", "end_turn": True, "role": "assistant"},
+        ]
+        self.openai_model = "some-model"
+        self.body = {
+            "conversation_id": "123",
+            "messages": [
+                {"role": "user", "content": "Hello"},
+                {"role": "assistant", "content": "Hi, how can I help?"},
+                {"role": "user", "content": "What is the meaning of life?"},
+            ],
+        }
+
+    @patch("code.app.app.get_message_orchestrator")
+    @patch("code.app.app.get_orchestrator_config")
+    def test_converstation_custom_returns_correct_response(
+        self, get_orchestrator_config_mock, get_message_orchestrator_mock
+    ):
+        # given
+        get_orchestrator_config_mock.return_value = self.orchestrator_config
+
+        message_orchestrator_mock = Mock()
+        message_orchestrator_mock.handle_message.return_value = self.messages
+        get_message_orchestrator_mock.return_value = message_orchestrator_mock
+
+        os.environ["AZURE_OPENAI_MODEL"] = self.openai_model
+
+        # when
+        response = app.test_client().post(
+            "/api/conversation/custom",
+            headers={"content-type": "application/json"},
+            json=self.body,
+        )
+
+        # then
+        assert response.status_code == 200
+        assert response.json == {
+            "choices": [{"messages": self.messages}],
+            "created": "response.created",
+            "id": "response.id",
+            "model": self.openai_model,
+            "object": "response.object",
+        }
+
+    @patch("code.app.app.get_message_orchestrator")
+    @patch("code.app.app.get_orchestrator_config")
+    def test_converstation_custom_calls_message_orchestrator_correctly(
+        self, get_orchestrator_config_mock, get_message_orchestrator_mock
+    ):
+        # given
+        get_orchestrator_config_mock.return_value = self.orchestrator_config
+
+        message_orchestrator_mock = Mock()
+        message_orchestrator_mock.handle_message.return_value = self.messages
+        get_message_orchestrator_mock.return_value = message_orchestrator_mock
+
+        os.environ["AZURE_OPENAI_MODEL"] = self.openai_model
+
+        # when
+        app.test_client().post(
+            "/api/conversation/custom",
+            headers={"content-type": "application/json"},
+            json=self.body,
+        )
+
+        # then
+        message_orchestrator_mock.handle_message.assert_called_once_with(
+            user_message=self.body["messages"][-1]["content"],
+            chat_history=self.body["messages"][:-1],
+            conversation_id=self.body["conversation_id"],
+            orchestrator=self.orchestrator_config,
+        )
+
+    @patch("code.app.app.get_orchestrator_config")
+    def test_converstation_custom_returns_error_resonse_on_exception(
+        self, get_orchestrator_config_mock
+    ):
+        # given
+        get_orchestrator_config_mock.side_effect = Exception("An error occurred")
+
+        # when
+        response = app.test_client().post(
+            "/api/conversation/custom",
+            headers={"content-type": "application/json"},
+            json=self.body,
+        )
+
+        # then
+        assert response.status_code == 500
+        assert response.json == {
+            "error": "Exception in /api/conversation/custom. See log for more details."
+        }
+
+    @patch("code.app.app.get_message_orchestrator")
+    @patch("code.app.app.get_orchestrator_config")
+    def test_converstation_custom_allows_multiple_messages_from_user(
+        self, get_orchestrator_config_mock, get_message_orchestrator_mock
+    ):
+        """This can happen if there was an error getting a response from the assistant for the previous user message."""
+
+        # given
+        get_orchestrator_config_mock.return_value = self.orchestrator_config
+
+        message_orchestrator_mock = Mock()
+        message_orchestrator_mock.handle_message.return_value = self.messages
+        get_message_orchestrator_mock.return_value = message_orchestrator_mock
+
+        os.environ["AZURE_OPENAI_MODEL"] = self.openai_model
+
+        body = {
+            "conversation_id": "123",
+            "messages": [
+                {"role": "user", "content": "Hello"},
+                {"role": "assistant", "content": "Hi, how can I help?"},
+                {"role": "user", "content": "What is the meaning of life?"},
+                {
+                    "role": "user",
+                    "content": "Please, what is the meaning of life?",
+                },
+            ],
+        }
+
+        # when
+        response = app.test_client().post(
+            "/api/conversation/custom",
+            headers={"content-type": "application/json"},
+            json=body,
+        )
+
+        # then
+        assert response.status_code == 200
+        message_orchestrator_mock.handle_message.assert_called_once_with(
+            user_message=body["messages"][-1]["content"],
+            chat_history=body["messages"][:-1],
+            conversation_id=body["conversation_id"],
+            orchestrator=self.orchestrator_config,
+        )