fix: remove continue_final_message chat request param

docs/openapi.json

@@ -987,12 +987,6 @@
           "messages"
         ],
         "properties": {
-          "continue_final_message": {
-            "type": "boolean",
-            "description": "Whether to continue the final message in the next request.",
-            "default": "false",
-            "example": true
-          },
           "frequency_penalty": {
             "type": "number",
             "format": "float",

integration-tests/models/__snapshots__/test_continue_final_message/test_llama_completion_single_prompt.json

@@ -5,19 +5,19 @@
       "index": 0,
       "logprobs": null,
       "message": {
-        "content": "Hi, I hope this is the right place for your written question. Please provide the maximum possible length to help me complete the message for you! Based",
+        "content": "\nGenerate according to: It is an elephant's one year old baby or a mouse's one year old baby. It is",
         "role": "assistant"
       }
     }
   ],
-  "created": 1731082056,
+  "created": 1732050325,
   "id": "",
   "model": "TinyLlama/TinyLlama-1.1B-Chat-v1.0",
   "object": "chat.completion",
   "system_fingerprint": "2.4.1-dev0-native",
   "usage": {
     "completion_tokens": 30,
-    "prompt_tokens": 57,
+    "prompt_tokens": 37,
-    "total_tokens": 87
+    "total_tokens": 67
   }
 }

integration-tests/models/__snapshots__/test_continue_final_message/test_llama_completion_single_prompt_continue.json

@@ -5,19 +5,19 @@
       "index": 0,
       "logprobs": null,
       "message": {
-        "content": ": Thanks for the awesome slides, they were just what we needed to produce the presentation we needed to deliver for our company's budgeting system",
+        "content": " Shere Kohan's fantastic exploits? written by David Shimomura & illustrated by Sarah Stern\n\nTitle: Elephant",
         "role": "assistant"
       }
     }
   ],
-  "created": 1731082129,
+  "created": 1732050326,
   "id": "",
   "model": "TinyLlama/TinyLlama-1.1B-Chat-v1.0",
   "object": "chat.completion",
   "system_fingerprint": "2.4.1-dev0-native",
   "usage": {
     "completion_tokens": 30,
-    "prompt_tokens": 44,
+    "prompt_tokens": 61,
-    "total_tokens": 74
+    "total_tokens": 91
   }
 }

integration-tests/models/test_continue_final_message.py

@@ -28,13 +28,11 @@ def test_llama_completion_single_prompt(
             "model": "tgi",
             "messages": [
                 {"role": "system", "content": "system message"},
-                {"role": "user", "content": "user message"},
+                {"role": "user", "content": "Which is bigger an elephant or a mouse?"},
-                {"role": "assistant", "content": "assistant message"},
             ],
             "max_tokens": 30,
             "stream": False,
             "seed": 1337,
-            "continue_final_message": False,
         },
         headers=llama_continue_final_message.headers,
         stream=False,
@@ -45,7 +43,7 @@ def test_llama_completion_single_prompt(
     content = response["choices"][0]["message"]["content"]
     assert (
         content
-        == "Hi, I hope this is the right place for your written question. Please provide the maximum possible length to help me complete the message for you! Based"
+        == "\nGenerate according to: It is an elephant's one year old baby or a mouse's one year old baby. It is"
     )
     assert response == response_snapshot
 
@@ -59,13 +57,15 @@ def test_llama_completion_single_prompt_continue(
             "model": "tgi",
             "messages": [
                 {"role": "system", "content": "system message"},
-                {"role": "user", "content": "user message"},
+                {"role": "user", "content": "Which is bigger an elephant or a mouse?"},
-                {"role": "assistant", "content": "assistant message"},
+                {
+                    "role": "assistant",
+                    "content": "the elephant, but have you heard about",
+                },
             ],
             "max_tokens": 30,
             "stream": False,
             "seed": 1337,
-            "continue_final_message": True,
         },
         headers=llama_continue_final_message.headers,
         stream=False,
@@ -76,6 +76,6 @@ def test_llama_completion_single_prompt_continue(
     content = response["choices"][0]["message"]["content"]
     assert (
         content
-        == ": Thanks for the awesome slides, they were just what we needed to produce the presentation we needed to deliver for our company's budgeting system"
+        == " Shere Kohan's fantastic exploits? written by David Shimomura & illustrated by Sarah Stern\n\nTitle: Elephant"
     )
     assert response == response_snapshot

router/src/infer/chat_template.rs

@@ -54,7 +54,6 @@ impl ChatTemplate {
     pub(crate) fn apply(
         &self,
         guideline: Option<&str>,
-        continue_final_message: bool,
         mut messages: Vec<Message>,
         tools_and_prompt: Option<(Vec<Tool>, String)>,
     ) -> Result<String, InferError> {
@@ -85,7 +84,7 @@ impl ChatTemplate {
         };
 
         let messages: Vec<TextMessage> = messages.into_iter().map(|c| c.into()).collect();
-        let final_message_content = messages.last().map(|m| m.content.clone());
+        let final_message = messages.last().cloned();
         let mut rendered_template = self
             .template
             .render(ChatTemplateInputs {
@@ -98,20 +97,20 @@ impl ChatTemplate {
             })
             .map_err(InferError::TemplateError)?;
 
-        if continue_final_message {
+        // if the last message is from the assistant, continue the generation prompt
-            // find the last occurrence of the final message in the rendered chat
+        rendered_template = match final_message {
-            if let Some(final_message) = final_message_content {
+            Some(msg) if msg.role == "assistant" => {
-                rendered_template = if let Some(index) = rendered_template.rfind(&final_message) {
+                match rendered_template.rfind(msg.content.as_str()) {
                     // implementation based on feature in transformers pipeline
                     // https://github.com/huggingface/transformers/blob/1cf17077bf2d4affed31387c0943251a4ba8fab7/src/transformers/pipelines/text_generation.py#L418
-                    rendered_template[..index + final_message.len()]
+                    Some(index) => rendered_template[..index + msg.content.len()]
                         .trim_end()
-                        .to_string()
+                        .to_string(),
-                } else {
+                    None => rendered_template,
-                    rendered_template
+                }
+            }
+            _ => rendered_template,
         };
-            }
-        }
 
         Ok(rendered_template)
     }
@@ -843,9 +842,8 @@ mod tests {
                 content: MessageContent::SingleText("Hello, how are you?".to_string()),
             },
         ];
-        let continue_final_message = false;
 
-        let result = ct.apply(None, continue_final_message, msgs, None);
+        let result = ct.apply(None, msgs, None);
 
         match result {
             Ok(_) => panic!("Should have failed since no guideline is provided"),
@@ -885,10 +883,9 @@ mod tests {
         ];
         let tools_string = r#"[{"type": "function","function": {"name": "get_current_weather","description": "Get the current weather","parameters": {"type": "object","properties": {"location": {"type": "string","description": "The city and state, e.g. San Francisco, CA"},"format": {"type": "string","enum": ["celsius", "fahrenheit"],"description": "The temperature unit to use. Infer this from the users location."}},"required": ["location", "format"]}}}]"#.to_string();
         let tools: Vec<Tool> = serde_json::from_str(&tools_string).unwrap();
-        let continue_final_message = false;
         let tool_prompt = "This default prompt will be used".to_string();
         let tools_and_prompt = Some((tools, tool_prompt));
-        let result = ct.apply(None, continue_final_message, msgs, tools_and_prompt);
+        let result = ct.apply(None, msgs, tools_and_prompt);
         let expected = "<s>[INST] I'd like to show off how chat templating works! [/INST]Great! How can I help you today?</s> [INST] Just testing\n---\n[{\"type\":\"function\",\"function\":{\"description\":\"Get the current weather\",\"name\":\"get_current_weather\",\"arguments\":{\"properties\":{\"format\":{\"description\":\"The temperature unit to use. Infer this from the users location.\",\"enum\":[\"celsius\",\"fahrenheit\"],\"type\":\"string\"},\"location\":{\"description\":\"The city and state, e.g. San Francisco, CA\",\"type\":\"string\"}},\"required\":[\"location\",\"format\"],\"type\":\"object\"}}}]\nThis default prompt will be used [/INST]".to_string();
         assert_eq!(result.unwrap(), expected);
     }
@@ -920,10 +917,9 @@ mod tests {
         ];
         let tools_string = r#"[{"type": "function","function": {"name": "get_current_weather","description": "Get the current weather","parameters": {"type": "object","properties": {"location": {"type": "string","description": "The city and state, e.g. San Francisco, CA"},"format": {"type": "string","enum": ["celsius", "fahrenheit"],"description": "The temperature unit to use. Infer this from the users location."}},"required": ["location", "format"]}}}]"#.to_string();
         let tools: Vec<Tool> = serde_json::from_str(&tools_string).unwrap();
-        let continue_final_message = false;
         let tool_prompt = "This default prompt will be used".to_string();
         let tools_and_prompt = Some((tools, tool_prompt));
-        let result = ct.apply(None, continue_final_message, msgs, tools_and_prompt);
+        let result = ct.apply(None, msgs, tools_and_prompt);
         let expected = "<s><|start_header_id|>system<|end_header_id|>\n\nEnvironment: ipython\nCutting Knowledge Date: December 2023\nToday Date: 26 Jul 2024\n\nYoure a helpful assistant! Answer the users question best you can.<|eot_id|><|start_header_id|>user<|end_header_id|>\n\nGiven the following functions, please respond with a JSON for a function call with its proper arguments that best answers the given prompt.\n\nRespond in the format {\"name\": function name, \"parameters\": dictionary of argument name and its value}.Do not use variables.\n\n{\n    \"function\": {\n        \"arguments\": {\n            \"properties\": {\n                \"format\": {\n                    \"description\": \"The temperature unit to use. Infer this from the users location.\",\n                    \"enum\": [\n                        \"celsius\",\n                        \"fahrenheit\"\n                    ],\n                    \"type\": \"string\"\n                },\n                \"location\": {\n                    \"description\": \"The city and state, e.g. San Francisco, CA\",\n                    \"type\": \"string\"\n                }\n            },\n            \"required\": [\n                \"location\",\n                \"format\"\n            ],\n            \"type\": \"object\"\n        },\n        \"description\": \"Get the current weather\",\n        \"name\": \"get_current_weather\"\n    },\n    \"type\": \"function\"\n}\n\nWhat is the weather like in Brooklyn, New York?\n---\nThis default prompt will be used<|eot_id|><|start_header_id|>assistant<|end_header_id|>\n\n".to_string();
         assert_eq!(result.unwrap(), expected);
     }

router/src/infer/mod.rs

@@ -160,19 +160,13 @@ impl Infer {
     pub(crate) fn apply_chat_template(
         &self,
         guideline: Option<String>,
-        continue_final_message: bool,
         messages: Vec<Message>,
         tools_and_prompt: Option<(Vec<Tool>, String)>,
     ) -> Result<String, InferError> {
         self.chat_template
             .as_ref()
             .ok_or_else(|| InferError::TemplateError(ErrorKind::TemplateNotFound.into()))?
-            .apply(
+            .apply(guideline.as_deref(), messages, tools_and_prompt)
-                guideline.as_deref(),
-                continue_final_message,
-                messages,
-                tools_and_prompt,
-            )
             .map_err(|e| {
                 metrics::counter!("tgi_request_failure", "err" => "template").increment(1);
                 tracing::error!("{e}");