fix(expo): key the offline resource cache by the full publishable key

.changeset/expo-resource-cache-key-per-instance.md

@@ -0,0 +1,5 @@
+---
+'@clerk/expo': patch
+---
+
+Fix the offline resource cache so an app that switches Clerk instances no longer starts offline with the previous instance's cached user and session.

packages/expo/src/cache/ResourceCache.ts

@@ -14,7 +14,7 @@ function createResourceCache<T>(key: string): ResourceCache<T> {
     if (!opts.storage || !opts.publishableKey) {
       throw new Error(`Clerk: ResourceCache for ${key} requires storage and publishableKey!`);
     }
-    itemKey = `${key}_${opts.publishableKey.slice(-5)}`;
+    itemKey = `${key}_${opts.publishableKey.split('=').join('')}`;
     storage = opts.storage();
   };
 

packages/expo/src/cache/__tests__/ResourceCache.test.ts

@@ -0,0 +1,48 @@
+import { beforeEach, describe, expect, test } from 'vitest';
+
+import type { IStorage } from '../../provider/singleton/types';
+import { SessionJWTCache } from '../ResourceCache';
+
+const store = new Map<string, string>();
+const storage = (): IStorage => ({
+  get: key => Promise.resolve(store.get(key) ?? null),
+  set: (key, value) => {
+    store.set(key, value);
+    return Promise.resolve();
+  },
+});
+
+const buildKey = (frontendApi: string) => `pk_test_${btoa(`${frontendApi}$`)}`;
+
+beforeEach(() => {
+  store.clear();
+});
+
+describe('ResourceCache', () => {
+  test('isolates entries between instances whose publishable keys share a suffix', async () => {
+    const first = buildKey('a.clerk.accounts.dev');
+    const second = buildKey('foo-bar-12.clerk.accounts.dev');
+    expect(first.slice(-5)).toBe(second.slice(-5));
+
+    SessionJWTCache.init({ publishableKey: first, storage });
+    await SessionJWTCache.save('jwt-for-first');
+
+    SessionJWTCache.init({ publishableKey: second, storage });
+    await expect(SessionJWTCache.load()).resolves.toBeNull();
+
+    SessionJWTCache.init({ publishableKey: first, storage });
+    await expect(SessionJWTCache.load()).resolves.toBe('jwt-for-first');
+  });
+
+  test('uses storage keys that expo-secure-store accepts', async () => {
+    const padded = buildKey('ab.clerk.accounts.dev');
+    expect(padded.endsWith('=')).toBe(true);
+
+    SessionJWTCache.init({ publishableKey: padded, storage });
+    await SessionJWTCache.save('jwt');
+
+    for (const storedKey of store.keys()) {
+      expect(storedKey).toMatch(/^[\w.-]+$/);
+    }
+  });
+});