ui phase 10

client/src/services/tickets/hooks/useDiscardFailedMessage.ts

@@ -0,0 +1,20 @@
+import { useQueryClient } from '@tanstack/react-query';
+import { ticketKeys } from '../keys';
+import type { TicketDetail } from '../types';
+
+/**
+ * The composer's "discard and retype" affordance on a failed bubble (§3.3) — removes it from the cached
+ * thread so the caller can restore its text into the composer draft. Not a mutation: a message that never
+ * left the client has nothing to tell the server.
+ */
+export function useDiscardFailedMessage() {
+  const queryClient = useQueryClient();
+  return (ticketId: number, clientMessageId: string): void => {
+    const key = ticketKeys.detail(ticketId);
+    queryClient.setQueryData<TicketDetail>(key, (current) =>
+      current
+        ? { ...current, messages: current.messages.filter((m) => m.clientMessageId !== clientMessageId) }
+        : current,
+    );
+  };
+}