Add system message test for chat completions and refactor ResponseFor…

…mat field

src/client/chat_completions/chat_completions.rs

@@ -69,7 +69,10 @@ impl DeepSeekClient {
 #[cfg(test)]
 mod tests {
     use super::*;
-    use crate::client::chat_completions::request::{Message, Model, Temperature};
+    use crate::{
+        client::chat_completions::request::{Message, Model, Temperature},
+        request::ResponseFormat,
+    };
 
     #[tokio::test]
     #[ignore]
@@ -106,7 +109,22 @@ mod tests {
         let response = client.chat_completions(request).await.unwrap();
         assert!(!response.choices.is_empty());
     }
-
+    #[tokio::test]
+    #[ignore]
+    async fn test_chat_completions_with_system_message_json() {
+        dotenvy::dotenv().ok();
+        let client = DeepSeekClient::default().unwrap();
+        let request = RequestBody::new_messages(vec![
+            Message::new_system_message("You are a helpful assistant.".to_string()),
+            Message::new_user_message("What is 2+2?".to_string()),
+            Message::new_user_message(r#"```json { "output" : <value>} "#.to_string()),
+        ])
+        .with_response_format(ResponseFormat::new(
+            crate::request::ResponseFormatType::Json,
+        ));
+        let response = client.chat_completions(request).await.unwrap();
+        assert!(!response.choices.is_empty());
+    }
     #[tokio::test]
     #[ignore]
     async fn test_chat_completions_with_reasoner_model() {

src/client/chat_completions/request.rs

@@ -273,18 +273,21 @@ impl fmt::Display for PresencePenalty {
 #[derive(Debug, Serialize, Deserialize, Clone, PartialEq, Eq)]
 
 pub struct ResponseFormat {
-    pub response_format: ResponseFormatType,
+    #[serde(rename = "type")]
+    pub type_: ResponseFormatType,
 }
 impl Default for ResponseFormat {
     fn default() -> Self {
         ResponseFormat {
-            response_format: ResponseFormatType::Json,
+            type_: ResponseFormatType::Json,
         }
     }
 }
 impl ResponseFormat {
     pub fn new(response_format: ResponseFormatType) -> Self {
-        ResponseFormat { response_format }
+        ResponseFormat {
+            type_: response_format,
+        }
     }
 }
 #[derive(Debug, Serialize, Deserialize, Clone, PartialEq, Eq)]
@@ -501,15 +504,15 @@ mod tests {
         let text_format = ResponseFormat::new(ResponseFormatType::Text);
         let default_format = ResponseFormat::default();
 
-        match default_format.response_format {
+        match default_format.type_ {
             ResponseFormatType::Json => assert!(true),
             _ => assert!(false, "Default should be Json"),
         }
-        match json_format.response_format {
+        match json_format.type_ {
             ResponseFormatType::Json => assert!(true),
             _ => assert!(false, "Expected Json"),
         }
-        match text_format.response_format {
+        match text_format.type_ {
             ResponseFormatType::Text => assert!(true),
             _ => assert!(false, "Expected Text"),
         }