fix(chat): capture du final et cause réelle des fins de tour « Le modèle n'a renvoyé aucune réponse. » — #231

crates/app-tauri/src/chat.rs

@@ -35,6 +35,11 @@ use domain::ports::{
 };
 
 use crate::dto::{ReplyChunk, ReplyProgressDto, ReplyProgressKindDto, ReplyProgressStageDto};
+
+/// Visible terminal message when a structured stream ends without the authoritative
+/// `ReplyEvent::Final`.
+pub const MODEL_RESPONSE_NOT_FINALIZED_MESSAGE: &str =
+    "La réponse du modèle n'a pas pu être finalisée.";
 use crate::stream::TauriChannelSink;
 
 /// Maximum number of recent chat chunks retained for transport reattach replay.
@@ -338,3 +343,12 @@ pub fn chunk_from_event(event: ReplyEvent) -> Option<ReplyChunk> {
         ReplyEvent::RateLimited { .. } => None,
     }
 }
+
+/// Terminal wire chunk for an exhausted structured stream that never produced the
+/// authoritative `ReplyEvent::Final`.
+#[must_use]
+pub fn unfinished_turn_chunk() -> ReplyChunk {
+    ReplyChunk::Error {
+        message: MODEL_RESPONSE_NOT_FINALIZED_MESSAGE.to_owned(),
+    }
+}

crates/app-tauri/src/commands.rs

@@ -2512,7 +2512,6 @@ pub async fn agent_send(
     let meta = state.structured_sessions.meta_for_session(&sid);
     std::thread::spawn(move || {
         let mut terminal_visible = false;
-        let mut streamed_text = String::new();
         let mut settler = crate::chat::ProgressSettler::default();
         for event in stream {
             // Non-terminal, sans contenu chat : un signal de limite alimente le service
@@ -2543,9 +2542,6 @@ pub async fn agent_send(
             let Some(chunk) = crate::chat::chunk_from_event(event) else {
                 continue;
             };
-            if let ReplyChunk::TextDelta { text } = &chunk {
-                streamed_text.push_str(text);
-            }
             if matches!(chunk, ReplyChunk::Final { .. } | ReplyChunk::Error { .. }) {
                 terminal_visible = true;
             }
@@ -2556,15 +2552,7 @@ pub async fn agent_send(
             let _ = bridge.send_output_settled(&sid, &mut settler, chunk);
         }
         if !terminal_visible {
-            let chunk = if streamed_text.trim().is_empty() {
-                ReplyChunk::Error {
-                    message: "Le modèle n'a renvoyé aucune réponse.".to_owned(),
-                }
-            } else {
-                ReplyChunk::Final {
-                    content: streamed_text,
-                }
-            };
+            let chunk = crate::chat::unfinished_turn_chunk();
             let _ = bridge.send_output_settled(&sid, &mut settler, chunk);
         }
         bridge.detach_if(&sid, gen);