feat: add test and serialize tool messages

integration-tests/models/__snapshots__/test_tools_llama/test_flash_llama_tool_reply_response.json

@@ -0,0 +1,26 @@
+{
+  "choices": [
+    {
+      "finish_reason": "length",
+      "index": 0,
+      "logprobs": null,
+      "message": {
+        "content": "I'm an AI and do not have access to real-time data. However,  based on location information (Paris) I can provide general information. \n\nThe temperature in Paris varies widely throughout the year. In the summer (June to August), the average high temperature is around 23°C (73°F), while in the winter (December to February), the average low temperature is around -1°C (30°F). \n\nTo get the current weather in Paris, I recommend checking a weather website or",
+        "name": null,
+        "role": "assistant",
+        "tool_calls": null
+      },
+      "usage": null
+    }
+  ],
+  "created": 1739903191,
+  "id": "",
+  "model": "meta-llama/Llama-3.1-8B-Instruct",
+  "object": "chat.completion",
+  "system_fingerprint": "3.1.1-dev0-native",
+  "usage": {
+    "completion_tokens": 100,
+    "prompt_tokens": 103,
+    "total_tokens": 203
+  }
+}

integration-tests/models/test_tools_llama.py

@@ -468,3 +468,42 @@ async def test_flash_llama_grammar_tools_sea_creatures_stream_function_object(
         == '{"function": {"_name": "get_n_day_weather_forecast", "location": "San Francisco, CA", "format": "celsius", "num_days":3}}<|eot_id|>'
     )
     assert last_response == response_snapshot
+
+
+@pytest.mark.asyncio
+@pytest.mark.private
+async def test_flash_llama_tool_reply_response(
+    flash_llama_grammar_tools, response_snapshot
+):
+    responses = await flash_llama_grammar_tools.chat(
+        max_tokens=100,
+        seed=43,
+        messages=[
+            {"role": "user", "content": "What's the weather like in Paris today?"},
+            {
+                "content": "",
+                "role": "assistant",
+                "tool_calls": [
+                    {
+                        "id": "0",
+                        "function": {
+                            "arguments": '{"longitude": 2.2945, "latitude": 48.8567}',
+                            "name": "get_weather",
+                            "description": None,
+                        },
+                        "type": "function",
+                    }
+                ],
+            },
+            {"role": "tool", "tool_call_id": "0", "content": "6.7"},
+        ],
+        stream=False,
+    )
+
+    assert responses.choices[0].message.tool_calls is None
+    assert (
+        responses.choices[0].message.content
+        == "I'm an AI and do not have access to real-time data. However,  based on location information (Paris) I can provide general information. \n\nThe temperature in Paris varies widely throughout the year. In the summer (June to August), the average high temperature is around 23°C (73°F), while in the winter (December to February), the average low temperature is around -1°C (30°F). \n\nTo get the current weather in Paris, I recommend checking a weather website or"
+    )
+
+    assert responses == response_snapshot

router/src/infer/chat_template.rs

@@ -73,10 +73,8 @@ impl ChatTemplate {
                     // if the `tools` variable is used in the template, we just append the tool_prompt
                     format!("\n---\n{}", tool_prompt)
                 };
-                if let Some(last_message) = messages.last_mut() {
+                if let Some(content) = messages.last_mut().and_then(|msg| msg.content.as_mut()) {
-                    if let Some(content) = last_message.content.as_mut() {
+                    content.push(MessageChunk::Text { text })
-                        content.push(MessageChunk::Text { text });
-                    }
                 }
                 Some(tools)
             }

router/src/lib.rs

@@ -1222,22 +1222,24 @@ pub struct TextMessage {
 
 impl From<Message> for TextMessage {
     fn from(value: Message) -> Self {
+        let content = value
+            .tool_calls
+            .map(|calls| serde_json::to_string(&calls).unwrap_or_default())
+            .map(MessageContent::SingleText)
+            .or(value.content)
+            .unwrap_or_else(|| MessageContent::SingleText(String::new()));
         TextMessage {
             role: value.role,
-            content: match value.content {
+            content: match content {
-                // If content is Some(MessageContent), handle it accordingly
+                MessageContent::SingleText(text) => text,
-                Some(MessageContent::SingleText(text)) => text,
+                MessageContent::MultipleChunks(chunks) => chunks
-                Some(MessageContent::MultipleChunks(chunks)) => {
+                    .into_iter()
-                    chunks.into_iter()
                     .map(|chunk| match chunk {
                         MessageChunk::Text { text } => text,
                         MessageChunk::ImageUrl { image_url } => format!("![]({})", image_url.url),
                     })
                     .collect::<Vec<_>>()
-                        .join("")
+                    .join(""),
-                }
-                // If content is None, use an empty string or a default message
-                None => String::new(), // or you could use "No content" or another placeholder
             },
         }
     }