refactor: centralize paired room role normalization (#193)

runners/shared/test/paired-room-role.test.ts

@@ -0,0 +1,26 @@
+import { describe, expect, it } from 'vitest';
+
+import {
+  PAIRED_ROOM_ROLES,
+  isPairedRoomRole,
+  normalizePairedRoomRole,
+  normalizePairedRoomRoleOrNull,
+} from '../src/paired-room-role.js';
+
+describe('paired room role helpers', () => {
+  it('defines the supported paired roles', () => {
+    expect(PAIRED_ROOM_ROLES).toEqual(['owner', 'reviewer', 'arbiter']);
+  });
+
+  it('recognizes valid paired room roles', () => {
+    expect(isPairedRoomRole('owner')).toBe(true);
+    expect(isPairedRoomRole('reviewer')).toBe(true);
+    expect(isPairedRoomRole('arbiter')).toBe(true);
+  });
+
+  it('normalizes unknown values consistently', () => {
+    expect(normalizePairedRoomRole('main')).toBeUndefined();
+    expect(normalizePairedRoomRole(null)).toBeUndefined();
+    expect(normalizePairedRoomRoleOrNull('main')).toBeNull();
+  });
+});