fix: forget an account's saved sender identities when it is signed out

src/lib/__tests__/identity-cache.test.ts

@@ -5,7 +5,7 @@ import fs from 'node:fs';
 import path from 'node:path';
 import AsyncStorage from '@react-native-async-storage/async-storage';
 import type { Identity } from '../../api/types';
-import { loadComposerIdentities, readCachedIdentities } from '../identity-cache';
+import { forgetCachedIdentities, loadComposerIdentities, readCachedIdentities } from '../identity-cache';
 
 const me = { id: 'i1', name: 'User A', email: 'usera@example.org', mayDelete: false } as Identity;
 const offline = () => Promise.reject(new Error('Network request failed'));
@@ -15,6 +15,14 @@ beforeEach(async () => {
 });
 
 describe('composer identities', () => {
+  it('drops the kept identities when the login leaves the device', async () => {
+    await loadComposerIdentities('usera@host', async () => [me]);
+    await forgetCachedIdentities('usera@host');
+    expect(await readCachedIdentities('usera@host')).toEqual([]);
+    const auth = fs.readFileSync(path.resolve(__dirname, '../../stores/auth-store.ts'), 'utf8');
+    expect(auth).toMatch(/async function forgetRemovedAccount\(accountId: string\): Promise<void> \{\s*void forgetCachedIdentities\(accountId\);/);
+  });
+
   it('keeps what the server said for the login', async () => {
     const result = await loadComposerIdentities('usera@host', async () => [me]);
     expect(result).toEqual({ identities: [me], fresh: true, error: null });

src/lib/identity-cache.ts

@@ -27,6 +27,13 @@ export async function readCachedIdentities(localAccountId: string | null | undef
   }
 }
 
+/** Drop the identities kept for a login that left this device. */
+export async function forgetCachedIdentities(localAccountId: string): Promise<void> {
+  try {
+    await AsyncStorage.removeItem(keyFor(localAccountId));
+  } catch { /* best effort */ }
+}
+
 /** Keep what the server just said, for the next composer opened offline. */
 export async function writeCachedIdentities(localAccountId: string | null | undefined, identities: Identity[]): Promise<void> {
   if (!localAccountId) return;

src/stores/auth-store.ts

@@ -1,3 +1,4 @@
+import { forgetCachedIdentities } from '../lib/identity-cache';
 import { create } from 'zustand';
 import {
   jmapClient,
@@ -176,6 +177,7 @@ function clearDeviceWideAccountData(): void {
 // until nobody is signed in. When it was the last account, the device-wide
 // data goes too.
 async function forgetRemovedAccount(accountId: string): Promise<void> {
+  void forgetCachedIdentities(accountId);
   try {
     const feeds = useCalendarSubscriptionsStore;
     // On a cold start the stored list may not have been read yet; written