fix(expo): Resolve Android native modules optionally (#9203)

Author: wobsoriano

.changeset/fix-android-optional-native-module.md

@@ -0,0 +1,5 @@
+---
+'@clerk/expo': patch
+---
+
+Fix a crash on Android in Expo Go where rendering `<ClerkProvider>` failed with `Cannot find native module 'ClerkExpo'`, even for JavaScript-only flows that use no native components.

packages/expo/src/specs/NativeClerkGoogleSignIn.android.ts

@@ -1,4 +1,4 @@
-import { requireNativeModule } from 'expo';
+import { requireOptionalNativeModule } from 'expo';
 
 type NativeMap = Record<string, unknown>;
 
@@ -10,4 +10,6 @@ interface Spec {
   signOut(): Promise<void>;
 }
 
-export default requireNativeModule<Spec>('ClerkGoogleSignIn');
+// Optional so getNativeModule() surfaces its actionable error rather than
+// throwing at import time.
+export default requireOptionalNativeModule<Spec>('ClerkGoogleSignIn');

packages/expo/src/specs/NativeClerkModule.android.ts

@@ -1,4 +1,4 @@
-import { requireNativeModule } from 'expo';
+import { requireOptionalNativeModule } from 'expo';
 
 interface Spec {
   // Exposed by Expo Modules EventEmitter for internal native client change events.
@@ -14,4 +14,5 @@ interface Spec {
   ): Promise<void>;
 }
 
-export default requireNativeModule<Spec>('ClerkExpo');
+// Optional so it resolves to null in Expo Go instead of throwing at import time.
+export default requireOptionalNativeModule<Spec>('ClerkExpo');

packages/expo/src/specs/__tests__/androidSpecs.test.ts

@@ -0,0 +1,51 @@
+import { beforeEach, describe, expect, test, vi } from 'vitest';
+
+const mocks = vi.hoisted(() => ({
+  available: {} as Record<string, unknown>,
+}));
+
+// Only returns a module when one is registered under the exact name requested.
+vi.mock('expo', () => ({
+  requireNativeModule: (name: string) => {
+    const nativeModule = mocks.available[name];
+    if (!nativeModule) {
+      throw new Error(`Cannot find native module '${name}'`);
+    }
+    return nativeModule;
+  },
+  requireOptionalNativeModule: (name: string) => mocks.available[name] ?? null,
+}));
+
+// Path is a variable because TypeScript cannot resolve the platform suffix in a
+// dynamic import.
+const importSpec = async (path: string) => (await import(path)).default;
+
+const importSpecs = async () => ({
+  clerkExpo: await importSpec('../NativeClerkModule.android'),
+  googleSignIn: await importSpec('../NativeClerkGoogleSignIn.android'),
+});
+
+describe('android native module specs', () => {
+  beforeEach(() => {
+    vi.resetModules();
+    mocks.available = {};
+  });
+
+  test('resolve to null instead of throwing when not compiled in (Expo Go)', async () => {
+    const { clerkExpo, googleSignIn } = await importSpecs();
+
+    expect(clerkExpo).toBeNull();
+    expect(googleSignIn).toBeNull();
+  });
+
+  test('resolve the module registered under the expected name (development build)', async () => {
+    const clerkExpoModule = { configure: vi.fn() };
+    const googleSignInModule = { signIn: vi.fn() };
+    mocks.available = { ClerkExpo: clerkExpoModule, ClerkGoogleSignIn: googleSignInModule };
+
+    const { clerkExpo, googleSignIn } = await importSpecs();
+
+    expect(clerkExpo).toBe(clerkExpoModule);
+    expect(googleSignIn).toBe(googleSignInModule);
+  });
+});