merge(chat): réponse du modèle non finalisée sur long message — #239 (QA verte)

crates/infrastructure/src/session/claude.rs

@@ -172,6 +172,28 @@ fn assistant_events(value: &Value) -> Vec<ReplyEvent> {
     events
 }
 
+fn append_text_fallback_final(events: &mut Vec<ReplyEvent>) {
+    let mut text = String::new();
+    let mut has_final = false;
+    let mut has_error = false;
+    let mut has_rate_limit = false;
+    for event in events.iter() {
+        match event {
+            ReplyEvent::TextDelta { text: delta } => text.push_str(delta),
+            ReplyEvent::Final { .. } => has_final = true,
+            ReplyEvent::Error { .. } => has_error = true,
+            ReplyEvent::RateLimited { .. } => has_rate_limit = true,
+            ReplyEvent::Progress { .. }
+            | ReplyEvent::ToolActivity { .. }
+            | ReplyEvent::Heartbeat
+            | ReplyEvent::Announcement { .. } => {}
+        }
+    }
+    if !has_final && !has_error && !has_rate_limit && !text.trim().is_empty() {
+        events.push(ReplyEvent::Final { content: text });
+    }
+}
+
 fn tool_use_preview(block: &Value) -> Option<String> {
     block
         .get("input")
@@ -424,7 +446,76 @@ impl ClaudeSdkSession {
         if let Some(id) = captured_id {
             *self.conversation_id.lock().expect("mutex sain") = Some(id);
         }
+        append_text_fallback_final(&mut events);
 
         Ok(Box::new(events.into_iter()))
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn assistant_line(text: &str) -> String {
+        serde_json::json!({
+            "type": "assistant",
+            "message": {
+                "role": "assistant",
+                "content": [{ "type": "text", "text": text }]
+            },
+            "session_id": "session-1"
+        })
+        .to_string()
+    }
+
+    #[test]
+    fn text_only_success_stream_gets_fallback_final() {
+        let mut events = Vec::new();
+        for line in [assistant_line("longue "), assistant_line("réponse")] {
+            events.extend(parse_event(&line).expect("valid assistant line").events);
+        }
+
+        append_text_fallback_final(&mut events);
+
+        assert_eq!(
+            events.last(),
+            Some(&ReplyEvent::Final {
+                content: "longue réponse".to_owned()
+            }),
+            "assistant text must remain usable when Claude omits a result line"
+        );
+    }
+
+    #[test]
+    fn fallback_final_does_not_mask_rate_limit_or_error() {
+        let mut limited = vec![
+            ReplyEvent::TextDelta {
+                text: "partiel".to_owned(),
+            },
+            ReplyEvent::RateLimited { resets_at_ms: None },
+        ];
+        append_text_fallback_final(&mut limited);
+        assert!(
+            limited
+                .iter()
+                .all(|event| !matches!(event, ReplyEvent::Final { .. })),
+            "rate-limited streams must remain non-final"
+        );
+
+        let mut failed = vec![
+            ReplyEvent::TextDelta {
+                text: "partiel".to_owned(),
+            },
+            ReplyEvent::Error {
+                message: "provider error".to_owned(),
+            },
+        ];
+        append_text_fallback_final(&mut failed);
+        assert!(
+            failed
+                .iter()
+                .all(|event| !matches!(event, ReplyEvent::Final { .. })),
+            "provider errors must not be converted to successful finals"
+        );
+    }
+}

crates/infrastructure/src/session/mod.rs

@@ -1513,11 +1513,10 @@ mod tests {
         );
     }
 
-    /// LIMITE/ÉCART (à arbitrer) : un flux SANS `Final` ne provoque PAS d'erreur au
-    /// niveau de l'adapter — `send()` renvoie Ok avec uniquement des deltas et AUCUN
-    /// `Final`. Le §17.9 D2 mentionne « flux sans Final ⇒ Io » ; l'adapter actuel ne
-    /// l'applique pas (c'est `send_blocking` côté application, lot D1, qui transforme
-    /// l'absence de Final en Timeout). Ce test PINNE le comportement réel observé.
+    /// Régression #239 : Claude peut fermer proprement après des blocs `assistant`
+    /// textuels sans ligne `result`. Ces deltas sont une réponse modèle exploitable :
+    /// l'adapter doit donc fabriquer un `Final` de secours, au lieu de laisser la
+    /// surface chat conclure à tort « réponse non finalisée ».
     #[tokio::test]
     async fn stream_without_final_is_silently_ok_at_adapter_level() {
         let fake = FakeCli::printing(&[
@@ -1533,11 +1532,18 @@ mod tests {
             None,
         );
         let events: Vec<_> = s.send("x").await.expect("send ok").collect();
-        let finals = events
+        let finals: Vec<_> = events
             .iter()
-            .filter(|e| matches!(e, ReplyEvent::Final { .. }))
-            .count();
-        assert_eq!(finals, 0, "comportement actuel: aucun Final fabriqué");
+            .filter_map(|e| match e {
+                ReplyEvent::Final { content } => Some(content.as_str()),
+                _ => None,
+            })
+            .collect();
+        assert_eq!(
+            finals,
+            vec!["a"],
+            "Claude text-only streams must yield one fallback Final"
+        );
         // L'id de conversation est tout de même capté (init lu).
         assert_eq!(s.conversation_id().as_deref(), Some("c"));
     }

frontend/src/features/tickets/useTicketAssistant.test.tsx

@@ -94,6 +94,32 @@ describe("useTicketAssistant — ticket #60 (no-reply terminal)", () => {
     expect(last.role).toBe("assistant");
     expect(last.pending).toBeFalsy();
     expect(last.text).toContain("Le modèle n'a renvoyé aucune réponse.");
+    expect(last.text).toContain("Échec sans contenu");
+  });
+
+  it("preserves streamed partial content when the terminal error says finalization failed", async () => {
+    const gw = new FakeTicketGateway();
+    const { result } = await openAndSend(gw);
+
+    act(() => {
+      gw.captured!({ kind: "textDelta", text: "Réponse partielle utile." });
+    });
+    act(() => {
+      gw.captured!({
+        kind: "error",
+        message: "La réponse du modèle n'a pas pu être finalisée.",
+      });
+    });
+
+    await waitFor(() => expect(result.current.busy).toBe(false));
+    const last = result.current.turns.at(-1)!;
+    expect(last.role).toBe("assistant");
+    expect(last.pending).toBeFalsy();
+    expect(last.text).toContain("Réponse partielle utile.");
+    expect(last.text).toContain("Réponse partielle — fin non reçue.");
+    expect(last.text).toContain(
+      "demandez à l'assistant de continuer à partir de la réponse partielle",
+    );
   });
 
   it("a non-empty final renders the answer and clears busy (nominal, no regression)", async () => {

frontend/src/features/tickets/useTicketAssistant.ts

@@ -52,6 +52,31 @@ function describe(e: unknown): string {
   return String(e);
 }
 
+function assistantFailureText(message: string, partialText: string): string {
+  const partial = partialText.trim();
+  const normalized = message.toLowerCase();
+  if (!partial) {
+    return [
+      `Échec sans contenu — ${message}`,
+      "Reprise: renvoyez le message ou reformulez-le en plusieurs parties.",
+    ].join("\n");
+  }
+
+  const label =
+    normalized.includes("tronqu") || normalized.includes("truncat")
+      ? "Réponse tronquée."
+      : normalized.includes("finalis") || normalized.includes("fin ")
+        ? "Réponse partielle — fin non reçue."
+        : "Réponse partielle — échec transitoire possible.";
+  return [
+    partialText,
+    "",
+    `Échec — ${label}`,
+    message,
+    "Reprise: demandez à l'assistant de continuer à partir de la réponse partielle ci-dessus.",
+  ].join("\n");
+}
+
 export function useTicketAssistant(
   projectId: string,
   issueRef: string,
@@ -136,12 +161,11 @@ export function useTicketAssistant(
             // Best-effort inline activity badge.
             next[i] = { ...next[i], text: `${next[i].text}\n· ${chunk.label}` };
           } else if (chunk.kind === "error") {
-            // Terminal fallback (ticket #60): the model returned no usable answer.
-            // Freeze the turn with the readable explanation so the bubble is never
-            // left empty and pending — the assistant no longer hangs silently.
+            // Terminal fallback: preserve any streamed content, then classify the
+            // failure so a partial answer is not hidden by the terminal error.
             next[i] = {
               role: "assistant",
-              text: `⚠️ ${chunk.message}`,
+              text: assistantFailureText(chunk.message, next[i].text),
               pending: false,
             };
           } else if (chunk.kind === "final") {