key routing persists across restarts

test/key-store.test.js

@@ -1,5 +1,5 @@
 import { describe, expect, it } from 'vitest';
-import { createKeyRotator, loadConfiguredKeys, parseKeys, parseKeysJson } from '../src/key-store.js';
+import { createKeyRotator, createRedisKeyRotator, loadConfiguredKeys, parseKeys, parseKeysJson } from '../src/key-store.js';
 
 describe('key store', () => {
   it('parses JSON keys and prefers the environment variable', async () => {
@@ -16,4 +16,21 @@ describe('key store', () => {
     const rotator = createKeyRotator(['a', 'b']);
     expect([rotator.next(), rotator.next(), rotator.next()]).toEqual(['a', 'b', 'a']);
   });
+
+  it('shares a Redis-backed rotation sequence across rotators', async () => {
+    const counters = new Map();
+    const client = {
+      incr: async (key) => {
+        const next = (counters.get(key) || 0) + 1;
+        counters.set(key, next);
+        return String(next);
+      },
+    };
+    const firstInstance = createRedisKeyRotator({ client, keys: ['a', 'b'], key: 'test:key-rotation' });
+    const restartedInstance = createRedisKeyRotator({ client, keys: ['a', 'b'], key: 'test:key-rotation' });
+
+    await expect(firstInstance.next()).resolves.toBe('a');
+    await expect(firstInstance.next()).resolves.toBe('b');
+    await expect(restartedInstance.next()).resolves.toBe('a');
+  });
 });