From fd5ccb459892f17a5bb7fbcd2953815db66d4951 Mon Sep 17 00:00:00 2001
From: murashit <murashit@proton.me>
Date: Fri, 29 May 2026 05:39:33 +0900
Subject: [PATCH] Reuse thread activation action

---
 .../chat/chat-app-server-controller.ts        | 15 ++----------
 src/features/chat/thread-resume.ts            | 24 +++++++++++++++----
 tests/features/chat/thread-resume.test.ts     | 16 +++++++++++++
 3 files changed, 38 insertions(+), 17 deletions(-)

diff --git a/src/features/chat/chat-app-server-controller.ts b/src/features/chat/chat-app-server-controller.ts
index 9d09aa40..7f540677 100644
--- a/src/features/chat/chat-app-server-controller.ts
+++ b/src/features/chat/chat-app-server-controller.ts
@@ -6,7 +6,6 @@ import {
   upsertMcpServerDiagnostic,
   type CapabilityProbeMethod,
 } from "../../app-server/compatibility";
-import { parseServiceTier } from "../../app-server/service-tier";
 import type { McpServerStatus } from "../../generated/app-server/v2/McpServerStatus";
 import type { Model } from "../../generated/app-server/v2/Model";
 import type { RateLimitSnapshot } from "../../generated/app-server/v2/RateLimitSnapshot";
@@ -14,6 +13,7 @@ import type { SkillMetadata } from "../../generated/app-server/v2/SkillMetadata"
 import type { SharedAppServerMetadata } from "../../runtime/shared-app-server-state";
 import { requestedOrConfiguredServiceTier, type RuntimeSnapshot } from "../../runtime/state";
 import type { ChatAction, ChatState, ChatStateStore } from "./chat-state";
+import { resumedThreadAction } from "./thread-resume";
 
 export interface ChatAppServerControllerHost {
   stateStore: ChatStateStore;
@@ -99,18 +99,7 @@ export class ChatAppServerController {
     if (!client) return null;
     const serviceTier = requestedOrConfiguredServiceTier(this.host.runtimeSnapshot());
     const response = await client.startThread(this.host.vaultPath, serviceTier);
-    this.dispatch({
-      type: "thread/resumed",
-      thread: response.thread,
-      cwd: response.cwd,
-      model: response.model,
-      reasoningEffort: response.reasoningEffort,
-      serviceTier: parseServiceTier(response.serviceTier),
-      approvalPolicy: response.approvalPolicy,
-      approvalsReviewer: response.approvalsReviewer,
-      activePermissionProfile: response.activePermissionProfile,
-      forceMessagesToBottom: true,
-    });
+    this.dispatch(resumedThreadAction({ response, forceMessagesToBottom: true }));
     this.host.forceMessagesToBottom();
     return response;
   }
diff --git a/src/features/chat/thread-resume.ts b/src/features/chat/thread-resume.ts
index 2b3540da..c8e1c846 100644
--- a/src/features/chat/thread-resume.ts
+++ b/src/features/chat/thread-resume.ts
@@ -1,14 +1,29 @@
 import { parseServiceTier } from "../../app-server/service-tier";
 import { upsertThread } from "../../domain/threads/model";
+import type { ReasoningEffort } from "../../generated/app-server/ReasoningEffort";
+import type { ActivePermissionProfile } from "../../generated/app-server/v2/ActivePermissionProfile";
+import type { ApprovalsReviewer } from "../../generated/app-server/v2/ApprovalsReviewer";
+import type { AskForApproval } from "../../generated/app-server/v2/AskForApproval";
 import type { Thread } from "../../generated/app-server/v2/Thread";
-import type { ThreadResumeResponse } from "../../generated/app-server/v2/ThreadResumeResponse";
 import type { ChatAction } from "./chat-state";
 import type { DisplayItem } from "./display/types";
 
+export interface ThreadActivationResponse {
+  thread: Thread;
+  cwd: string;
+  model: string;
+  serviceTier: string | null;
+  approvalPolicy: AskForApproval | null;
+  approvalsReviewer: ApprovalsReviewer | null;
+  activePermissionProfile: ActivePermissionProfile | null;
+  reasoningEffort: ReasoningEffort | null;
+}
+
 export interface ResumedThreadActionParams {
-  response: ThreadResumeResponse;
-  listedThreads: readonly Thread[];
+  response: ThreadActivationResponse;
+  listedThreads?: readonly Thread[];
   displayItems?: readonly DisplayItem[];
+  forceMessagesToBottom?: boolean;
 }
 
 export function resumedThreadAction(params: ResumedThreadActionParams): Extract<ChatAction, { type: "thread/resumed" }> {
@@ -24,6 +39,7 @@ export function resumedThreadAction(params: ResumedThreadActionParams): Extract<
     approvalsReviewer: response.approvalsReviewer,
     activePermissionProfile: response.activePermissionProfile,
     ...(params.displayItems ? { displayItems: params.displayItems } : {}),
-    listedThreads: upsertThread(params.listedThreads, response.thread),
+    ...(params.listedThreads ? { listedThreads: upsertThread(params.listedThreads, response.thread) } : {}),
+    ...(params.forceMessagesToBottom !== undefined ? { forceMessagesToBottom: params.forceMessagesToBottom } : {}),
   };
 }
diff --git a/tests/features/chat/thread-resume.test.ts b/tests/features/chat/thread-resume.test.ts
index d43f6480..c0ca13cd 100644
--- a/tests/features/chat/thread-resume.test.ts
+++ b/tests/features/chat/thread-resume.test.ts
@@ -30,6 +30,22 @@ describe("chat thread resume helpers", () => {
     });
     expect(action.listedThreads?.map((thread) => thread.id)).toEqual(["thread", "existing"]);
   });
+
+  it("can build thread start actions without mutating the thread list", () => {
+    const resumed = threadFixture("thread", "Started");
+
+    const action = resumedThreadAction({
+      response: responseFixture(resumed),
+      forceMessagesToBottom: true,
+    });
+
+    expect(action).toMatchObject({
+      type: "thread/resumed",
+      thread: resumed,
+      forceMessagesToBottom: true,
+    });
+    expect(action.listedThreads).toBeUndefined();
+  });
 });
 
 function responseFixture(thread: Thread): ThreadResumeResponse {