From c2633823fb5bfe39d9bb2d284d8bec6c111b9a06 Mon Sep 17 00:00:00 2001
From: Adam Malczewski <github@tradam.dev>
Date: Mon, 29 Jun 2026 12:12:18 +0900
Subject: feat(chat): cancel a queued steering message from the UI
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Implements the frontend for the cancel-queued-message backend feature
(transport-contract 0.23.0 → 0.24.0, ADDITIVE). While a turn is generating
and a user message is queued (awaiting steering delivery), the user can now
cancel a single queued message by id so it never runs.

- Consume the contract: regenerate the .dispatch/transport-contract.reference.md
  mirror to 0.24.0; add chat.queue.cancel to the exhaustive WsClientMessage
  guard (core/wire/conformance.ts) + its test.
- ChatTransport port accepts ChatQueueCancelMessage; cancelQueuedMessage(id)
  on the chat store + app store sends chat.queue.cancel { conversationId,
  messageId } (fire-and-forget, idempotent — the server no-ops an already-
  drained/unknown id).
- UI: a × cancel affordance per queued row in MessageQueueList.svelte,
  threaded through SurfaceView's onCancelQueuedMessage (dispatched on
  rendererId, never the surface id) and wired to store.cancelQueuedMessage.
  Optimistic removal (pure selectVisibleMessages/reconcileCancelledIds in
  logic/message-queue.ts) hides the row on click and reconciles from the
  message-queue surface's post-cancel snapshot. No new event handling — the
  existing surface subscription reflects the result.

Tests: +12 (chat store cancel op ×3, optimistic-removal logic ×11 already
existed pattern, MessageQueueList component cancel behavior ×9).

Repo fix: package.json + bun.lock were still pinning file:../dispatch-backend/...
(stale from the dispatch-backend → backend rename) — corrected to
file:../backend/packages/...; bun install now resolves natively with no
worktree symlink hack.

typecheck 0/0, 1140 tests green (run twice), biome clean, build OK.
---
 src/features/chat/store.test.ts | 72 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 72 insertions(+)

(limited to 'src/features/chat/store.test.ts')

diff --git a/src/features/chat/store.test.ts b/src/features/chat/store.test.ts
index 8f36994..aa5560f 100644
--- a/src/features/chat/store.test.ts
+++ b/src/features/chat/store.test.ts
@@ -318,6 +318,78 @@ describe("createChatStore", () => {
     });
   });
 
+  describe("cancelQueuedMessage (chat.queue.cancel)", () => {
+    it("posts a chat.queue.cancel with conversationId + messageId", () => {
+      const transport = createFakeTransport();
+      const historySync = createFakeHistorySync();
+      const metricsSync = createFakeMetricsSync();
+      const cache = createFakeCache();
+      const store = createChatStore({
+        conversationId: CONV_ID,
+        transport: transport.impl,
+        historySync: historySync.impl,
+        metricsSync: metricsSync.impl,
+        cache: cache.impl,
+      });
+
+      store.cancelQueuedMessage("msg-42");
+
+      expect(transport.sent).toHaveLength(0); // chat.send stays empty
+      expect(transport.sentQueue).toHaveLength(0); // chat.queue stays empty
+      expect(transport.sentCancels).toHaveLength(1);
+      expect(transport.sentCancels[0]?.type).toBe("chat.queue.cancel");
+      expect(transport.sentCancels[0]?.conversationId).toBe(CONV_ID);
+      expect(transport.sentCancels[0]?.messageId).toBe("msg-42");
+
+      store.dispose();
+    });
+
+    it("does NOT touch the transcript (a cancelled message never runs)", () => {
+      const transport = createFakeTransport();
+      const historySync = createFakeHistorySync();
+      const metricsSync = createFakeMetricsSync();
+      const cache = createFakeCache();
+      const store = createChatStore({
+        conversationId: CONV_ID,
+        transport: transport.impl,
+        historySync: historySync.impl,
+        metricsSync: metricsSync.impl,
+        cache: cache.impl,
+      });
+
+      store.cancelQueuedMessage("msg-42");
+
+      expect(store.chunks).toHaveLength(0); // no transcript echo / change
+      expect(store.error).toBeNull();
+
+      store.dispose();
+    });
+
+    it("sends for any messageId (cancel is idempotent server-side, no FE guard)", () => {
+      const transport = createFakeTransport();
+      const historySync = createFakeHistorySync();
+      const metricsSync = createFakeMetricsSync();
+      const cache = createFakeCache();
+      const store = createChatStore({
+        conversationId: CONV_ID,
+        transport: transport.impl,
+        historySync: historySync.impl,
+        metricsSync: metricsSync.impl,
+        cache: cache.impl,
+      });
+
+      // The server no-ops an already-drained / unknown id; the FE fires-and-
+      // forgetgets, so even a repeat cancel is forwarded.
+      store.cancelQueuedMessage("msg-42");
+      store.cancelQueuedMessage("msg-42");
+
+      expect(transport.sentCancels).toHaveLength(2);
+      expect(transport.sentCancels[1]?.messageId).toBe("msg-42");
+
+      store.dispose();
+    });
+  });
+
   it("chat.error sets error", () => {
     const transport = createFakeTransport();
     const historySync = createFakeHistorySync();
-- 
cgit v1.2.3