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,
+    });
+  });
+});