Extract message runtime role channel resolution

src/message-runtime-role-channels.test.ts

@@ -0,0 +1,56 @@
+import { describe, expect, it, vi } from 'vitest';
+
+import { resolvePairedRoleChannels } from './message-runtime-role-channels.js';
+import type { Channel } from './types.js';
+
+function makeChannel(name: string): Channel {
+  return {
+    name,
+    connect: vi.fn(),
+    sendMessage: vi.fn(),
+    isConnected: vi.fn(() => true),
+    ownsJid: vi.fn(() => false),
+    disconnect: vi.fn(),
+  } as unknown as Channel;
+}
+
+describe('message-runtime-role-channels', () => {
+  it('maps owner, reviewer, and arbiter roles to their runtime channels', () => {
+    const ownerChannel = makeChannel('discord-owner');
+    const reviewerChannel = makeChannel('discord-review');
+    const arbiterChannel = makeChannel('discord-arbiter');
+
+    const result = resolvePairedRoleChannels(
+      [ownerChannel, reviewerChannel, arbiterChannel],
+      ownerChannel,
+    );
+
+    expect(result).toEqual({
+      roleToChannel: {
+        owner: ownerChannel,
+        reviewer: reviewerChannel,
+        arbiter: arbiterChannel,
+      },
+      reviewerChannelName: 'discord-review',
+      foundReviewerChannel: reviewerChannel,
+      arbiterChannelName: 'discord-arbiter',
+      foundArbiterChannel: arbiterChannel,
+    });
+  });
+
+  it('keeps missing reviewer and arbiter channels explicit as null', () => {
+    const ownerChannel = makeChannel('discord-owner');
+
+    expect(resolvePairedRoleChannels([ownerChannel], ownerChannel)).toEqual({
+      roleToChannel: {
+        owner: ownerChannel,
+        reviewer: null,
+        arbiter: null,
+      },
+      reviewerChannelName: 'discord-review',
+      foundReviewerChannel: null,
+      arbiterChannelName: 'discord-arbiter',
+      foundArbiterChannel: null,
+    });
+  });
+});

src/message-runtime-role-channels.ts

@@ -0,0 +1,37 @@
+import { findChannelByName } from './router.js';
+import type { Channel, PairedRoomRole } from './types.js';
+
+export type PairedRoleChannels = Record<PairedRoomRole, Channel | null>;
+
+export interface PairedRoleChannelResolution {
+  roleToChannel: PairedRoleChannels;
+  reviewerChannelName: string;
+  foundReviewerChannel: Channel | null;
+  arbiterChannelName: string;
+  foundArbiterChannel: Channel | null;
+}
+
+export function resolvePairedRoleChannels(
+  channels: Channel[],
+  ownerChannel: Channel,
+): PairedRoleChannelResolution {
+  const reviewerChannelName = 'discord-review';
+  const foundReviewerChannel =
+    findChannelByName(channels, reviewerChannelName) ?? null;
+
+  const arbiterChannelName = 'discord-arbiter';
+  const foundArbiterChannel =
+    findChannelByName(channels, arbiterChannelName) ?? null;
+
+  return {
+    roleToChannel: {
+      owner: ownerChannel,
+      reviewer: foundReviewerChannel,
+      arbiter: foundArbiterChannel,
+    },
+    reviewerChannelName,
+    foundReviewerChannel,
+    arbiterChannelName,
+    foundArbiterChannel,
+  };
+}

src/message-runtime.ts

@@ -13,7 +13,7 @@ import {
   SERVICE_SESSION_SCOPE,
 } from './config.js';
 import { GroupQueue, GroupRunContext } from './group-queue.js';
-import { findChannel, findChannelByName, formatMessages } from './router.js';
+import { findChannel, formatMessages } from './router.js';
 import { isTriggerAllowed, loadSenderAllowlist } from './sender-allowlist.js';
 import { enqueueGenericFollowUpAfterDeliveryRetry as enqueueDeliveryRetryFollowUp } from './message-runtime-dispatch.js';
 import {
@@ -73,6 +73,7 @@ import {
   isDuplicateOfLastBotFinal,
   labelPairedSenders,
 } from './message-runtime-turns.js';
+import { resolvePairedRoleChannels } from './message-runtime-role-channels.js';
 
 export { isDuplicateOfLastBotFinal };
 
@@ -381,28 +382,13 @@ export function createMessageRuntime(deps: MessageRuntimeDeps): {
       return true;
     }
 
-    // For paired rooms, reviewer/arbiter outputs use their fixed role bots.
-    const reviewerChannelName = 'discord-review';
-    const foundReviewerChannel = findChannelByName(
-      deps.channels,
+    const {
+      roleToChannel,
       reviewerChannelName,
-    );
-
-    const arbiterChannelName = 'discord-arbiter';
-    const foundArbiterChannel = findChannelByName(
-      deps.channels,
+      foundReviewerChannel,
       arbiterChannelName,
-    );
-
-    // Resolve the correct Discord channel for a given task status.
-    const roleToChannel: Record<
-      'owner' | 'reviewer' | 'arbiter',
-      Channel | null
-    > = {
-      owner: channel,
-      reviewer: foundReviewerChannel || null,
-      arbiter: foundArbiterChannel || null,
-    };
+      foundArbiterChannel,
+    } = resolvePairedRoleChannels(deps.channels, channel);
     if (hasReviewerLease(chatJid)) {
       log.info(
         {