Handle Android secure store corruption.

jest.ts

@@ -188,7 +188,11 @@ jest.mock('expo-secure-store', () => {
     async getItemAsync (key: string, options?: unknown): Promise<null | string> {
       if (options === undefined) {
         await new Promise<void>((resolve) => setTimeout(resolve, 50))
-        return encryptedStorage.get(key) ?? null
+        if (key === 'Test Error-Throwing Key') {
+          throw new Error('Test Error')
+        } else {
+          return encryptedStorage.get(key) ?? null
+        }
       } else {
         throw new Error(
           'expo-secure-store.getItemAsync\'s mock does not support options.'

react-native/components/createSessionStoreManagerComponent/unit.tsx

@@ -8,7 +8,7 @@ import { createSessionStoreManagerComponent, SessionStore } from '../../..'
 type TestSession = { readonly value: number }
 
 test('displays the loading screen', async () => {
-  const sessionStore = new SessionStore<TestSession>({ value: 5 }, randomUUID().toLowerCase())
+  const sessionStore = new SessionStore<TestSession>({ value: 5 }, randomUUID().toLowerCase(), { report: jest.fn() })
   const SessionStoreManager = createSessionStoreManagerComponent(sessionStore)
 
   const renderer = TestRenderer.create(
@@ -45,7 +45,7 @@ test('displays the loading screen', async () => {
 })
 
 test('shows the ready screen once given time to load', async () => {
-  const sessionStore = new SessionStore<TestSession>({ value: 5 }, randomUUID().toLowerCase())
+  const sessionStore = new SessionStore<TestSession>({ value: 5 }, randomUUID().toLowerCase(), { report: jest.fn() })
   const SessionStoreManager = createSessionStoreManagerComponent(sessionStore)
 
   const renderer = TestRenderer.create(
@@ -84,7 +84,7 @@ test('shows the ready screen once given time to load', async () => {
 })
 
 test('re-renders when the session is changed externally once', async () => {
-  const sessionStore = new SessionStore<TestSession>({ value: 5 }, randomUUID().toLowerCase())
+  const sessionStore = new SessionStore<TestSession>({ value: 5 }, randomUUID().toLowerCase(), { report: jest.fn() })
   const SessionStoreManager = createSessionStoreManagerComponent(sessionStore)
 
   const renderer = TestRenderer.create(
@@ -124,7 +124,7 @@ test('re-renders when the session is changed externally once', async () => {
 })
 
 test('re-renders when the session is changed externally twice', async () => {
-  const sessionStore = new SessionStore<TestSession>({ value: 5 }, randomUUID().toLowerCase())
+  const sessionStore = new SessionStore<TestSession>({ value: 5 }, randomUUID().toLowerCase(), { report: jest.fn() })
   const SessionStoreManager = createSessionStoreManagerComponent(sessionStore)
 
   const renderer = TestRenderer.create(
@@ -165,7 +165,7 @@ test('re-renders when the session is changed externally twice', async () => {
 })
 
 test('re-renders when the session is changed internally once', async () => {
-  const sessionStore = new SessionStore<TestSession>({ value: 5 }, randomUUID().toLowerCase())
+  const sessionStore = new SessionStore<TestSession>({ value: 5 }, randomUUID().toLowerCase(), { report: jest.fn() })
   const SessionStoreManager = createSessionStoreManagerComponent(sessionStore)
 
   const renderer = TestRenderer.create(
@@ -207,7 +207,7 @@ test('re-renders when the session is changed internally once', async () => {
 })
 
 test('re-renders when the session is changed internally twice', async () => {
-  const sessionStore = new SessionStore<TestSession>({ value: 5 }, randomUUID().toLowerCase())
+  const sessionStore = new SessionStore<TestSession>({ value: 5 }, randomUUID().toLowerCase(), { report: jest.fn() })
   const SessionStoreManager = createSessionStoreManagerComponent(sessionStore)
 
   const renderer = TestRenderer.create(

react-native/services/SessionStore/index.tsx

@@ -1,6 +1,7 @@
 import * as SecureStore from 'expo-secure-store'
 import { EventEmitter } from 'events'
 import type { Json } from '../../types/Json'
+import type { ErrorReporterInterface } from '../../types/ErrorReporterInterface'
 
 /**
  * A wrapper around expo-secure-store which adds:
@@ -23,10 +24,12 @@ export class SessionStore<T extends Json> {
    *                         store.
    * @param secureStorageKey The key of the record to read from/write to
    *                         expo-secure-store.
+   * @param errorReporter    The error reporter to use.
    */
   constructor (
     private readonly initial: T,
-    private readonly secureStorageKey: string
+    private readonly secureStorageKey: string,
+    private readonly errorReporter: ErrorReporterInterface
   ) {}
 
   /**
@@ -64,7 +67,13 @@ export class SessionStore<T extends Json> {
     } else {
       this.unloaded = false
 
-      const raw = await SecureStore.getItemAsync(this.secureStorageKey)
+      let raw: null | string = null
+
+      try {
+        raw = await SecureStore.getItemAsync(this.secureStorageKey)
+      } catch (e) {
+        this.errorReporter.report(e)
+      }
 
       if (raw === null) {
         this.value = this.initial

react-native/services/SessionStore/readme.md

@@ -7,14 +7,24 @@ A wrapper around `expo-secure-store` which adds:
 - Change events.
 - A synchronous read/write API (with asynchronous write-back).
 
+## Android decryption failure handling
+
+Expo on Android unfortunately has a tendency to lose the ability to decrypt the
+secure store.  It's not known why this is, but when it happens, the only
+workaround is to catch the exception thrown by `expo-secure-store` and continue
+as though the store is empty.
+
+For this reason, any exceptions thrown by `expo-secure-store` during the load
+phase are ignored.
+
 ## Usage
 
 ```tsx
-import type { SessionStore } from "react-native-app-helpers";
+import type { SessionStore, errorReporter } from "react-native-app-helpers";
 
 type Session = `Session A` | `Session B`;
 
-const store = new SessionStore<Session>(`Session A`, `SecureStorage Key`);
+const store = new SessionStore<Session>(`Session A`, `SecureStorage Key`, errorReporter);
 
 
 await store.load();