feat: add shared jest tests for demo apps

CONTRIBUTING.md

@@ -19,6 +19,7 @@ We use [changesets](https://github.com/changesets/changesets) to make it easier
 - `lint` - runs linting on all JS/TS source files in the monorepo _[Turbo]_
 - `gradle-plugin:lint` - runs linting on the Brownfield Gradle plugin source code
 - `typecheck` - runs TypeScript type checking on all TS source files in the monorepo _[Turbo]_
+- `test:apps` - runs Jest for the React Native example apps under `apps/` (Expo 54, Expo 55, plain RN) _[Turbo]_
 - `build` - runs all `build*` tasks in the Turbo repo - see below for more details _[Turbo]_
 - `dev` - runs all `dev` tasks in all workspaces
 - `brownfield:plugin:publish:local` - publishes the Brownfield Gradle plugin to your local Maven repository for testing purposes
@@ -27,8 +28,30 @@ We use [changesets](https://github.com/changesets/changesets) to make it easier
 - `build:example:android-rn` - builds the example React Native app for Android (`apps/RNApp/android`)
 - `build:example:ios-rn` - builds the example React Native app for iOS (`apps/RNApp/ios`)
 - `build:example:android-consumer:expo55` - builds the example native Android consumer (`apps/AndroidApp`) app's flavor consuming the Expo 55 RN app (`apps/ExpoApp55`) artifact
-- - `build:example:android-consumer:expo54` - builds the example native Android consumer (`apps/AndroidApp`) app's flavor consuming the Expo 54 RN app (`apps/ExpoApp54`) artifact
-- - `build:example:android-consumer:vanilla` - builds the example native Android consumer (`apps/AndroidApp`) app's flavor consuming the vanilla RN app (`apps/RNApp`) artifact
+- `build:example:android-consumer:expo54` - builds the example native Android consumer (`apps/AndroidApp`) app's flavor consuming the Expo 54 RN app (`apps/ExpoApp54`) artifact
+- `build:example:android-consumer:vanilla` - builds the example native Android consumer (`apps/AndroidApp`) app's flavor consuming the vanilla RN app (`apps/RNApp`) artifact
 - `build:example:ios-consumer:expo55` - builds the example native iOS consumer app (`apps/AppleApp`) consuming the Expo 55 RN app (`apps/ExpoApp55`) artifact
 - `build:example:ios-consumer:expo54` - builds the example native iOS consumer app (`apps/AppleApp`) consuming the Expo 54 RN app (`apps/ExpoApp54`) artifact
 - `build:example:ios-consumer:vanilla` - builds the example native iOS consumer (`apps/AppleApp`) app's flavor consuming the vanilla RN app (`apps/RNApp`) artifact
+
+## Example app tests
+
+The React Native example apps share Jest utilities and test suites from `apps/brownfield-example-shared-tests`. Tests exercise integration with `@callstack/react-native-brownfield`, `@callstack/brownfield-navigation`, and `@callstack/brownie` as used in each demo.
+
+From the repository root:
+
+| Command | Description |
+| --- | --- |
+| `yarn test:apps` | Runs `test` in all workspaces under `apps/` that define it (via Turbo). |
+
+Per example app (run from the repo root):
+
+| Command | App |
+| --- | --- |
+| `yarn workspace @callstack/brownfield-example-rn-app test` | Plain React Native (`apps/RNApp`) |
+| `yarn workspace @callstack/brownfield-example-expo-app-54 test` | Expo SDK 54 (`apps/ExpoApp54`) |
+| `yarn workspace @callstack/brownfield-example-expo-app-55 test` | Expo SDK 55 (`apps/ExpoApp55`) |
+
+Package-level scripts (`yarn test` inside `apps/RNApp`, `apps/ExpoApp54`, or `apps/ExpoApp55`) invoke Jest with each app’s `jest.config.js`.
+
+The native-only sample apps (`apps/AppleApp`, `apps/AndroidApp`) use their platform test runners (Xcode / Gradle), not Jest.

apps/ExpoApp54/__tests__/brownfield.example.test.tsx

@@ -0,0 +1,12 @@
+import PostMessageTab from '../app/(tabs)/postMessage';
+import Counter from '../components/counter';
+import RNApp from '../RNApp';
+import {
+  runPostMessageTabSuite,
+  runCounterSuite,
+  runExpoRnAppSuite,
+} from '@callstack/brownfield-example-shared-tests';
+
+runPostMessageTabSuite('ExpoApp54', PostMessageTab);
+runCounterSuite('ExpoApp54', Counter);
+runExpoRnAppSuite('ExpoApp54', RNApp);

apps/ExpoApp54/jest.config.js

@@ -0,0 +1,30 @@
+const path = require('path');
+
+module.exports = {
+  preset: 'jest-expo',
+  setupFilesAfterEnv: ['<rootDir>/jest.setup.js'],
+  moduleNameMapper: {
+    '^react$': require.resolve('react'),
+    '^react/jsx-runtime$': require.resolve('react/jsx-runtime'),
+    '^react/jsx-dev-runtime$': require.resolve('react/jsx-dev-runtime'),
+    '^@testing-library/react-native$': require.resolve(
+      '@testing-library/react-native'
+    ),
+    '^@/(.*)$': '<rootDir>/$1',
+    '^@callstack/react-native-brownfield$': path.join(
+      __dirname,
+      '../../packages/react-native-brownfield/src/index.ts'
+    ),
+    '^@callstack/brownfield-navigation$': path.join(
+      __dirname,
+      '../../packages/brownfield-navigation/src/index.ts'
+    ),
+    '^@callstack/brownie$': path.join(
+      __dirname,
+      '../../packages/brownie/src/index.ts'
+    ),
+  },
+  transformIgnorePatterns: [
+    'node_modules/(?!((jest-)?react-native|@react-native(-community)?|@callstack/brownfield-example-shared-tests|expo|@expo|expo-modules-core)/)',
+  ],
+};

apps/ExpoApp54/jest.setup.js

@@ -0,0 +1 @@
+require('@callstack/brownfield-example-shared-tests/jest/setup');

apps/ExpoApp54/package.json

@@ -8,7 +8,8 @@
     "android": "expo run:android",
     "ios": "expo run:ios",
     "web": "expo start --web",
-    "lint": "expo lint",
+    "lint": "expo lint --no-cache",
+    "test": "jest --config jest.config.js",
     "prebuild": "expo prebuild",
     "brownfield:prepare:android:ci": "cd .. && node --experimental-strip-types --no-warnings ./scripts/prepare-android-build-gradle-for-ci.ts ExpoApp54",
     "brownfield:package:android": "brownfield package:android --module-name brownfieldlib --variant release",
@@ -41,9 +42,15 @@
     "react-native-worklets": "0.5.1"
   },
   "devDependencies": {
+    "@callstack/brownfield-example-shared-tests": "workspace:^",
+    "@testing-library/react-native": "^13.3.3",
+    "@types/jest": "^30.0.0",
     "@types/react": "~19.1.10",
     "eslint": "^9.25.0",
     "eslint-config-expo": "~10.0.0",
+    "jest": "^29.7.0",
+    "jest-expo": "~54.0.16",
+    "react-test-renderer": "19.1.0",
     "typescript": "~5.9.3"
   },
   "brownie": {

apps/ExpoApp55/__tests__/brownfield.example.test.tsx

@@ -0,0 +1,12 @@
+import PostMessageTab from '../src/app/postMessage';
+import Counter from '../src/components/counter';
+import RNApp from '../RNApp';
+import {
+  runPostMessageTabSuite,
+  runCounterSuite,
+  runExpoRnAppSuite,
+} from '@callstack/brownfield-example-shared-tests';
+
+runPostMessageTabSuite('ExpoApp55', PostMessageTab);
+runCounterSuite('ExpoApp55', Counter);
+runExpoRnAppSuite('ExpoApp55', RNApp);

apps/ExpoApp55/eslint.config.js

@@ -1,10 +1,18 @@
 // https://docs.expo.dev/guides/using-eslint/
 const { defineConfig } = require('eslint/config');
 const expoConfig = require('eslint-config-expo/flat');
+const globals = require('globals');
 
 module.exports = defineConfig([
   expoConfig,
   {
     ignores: ['dist/*'],
   },
+  // Jest config is executed by Node (CommonJS); teach ESLint Node globals like __dirname.
+  {
+    files: ['jest.config.js'],
+    languageOptions: {
+      globals: globals.node,
+    },
+  },
 ]);

apps/ExpoApp55/jest.config.js

@@ -0,0 +1,33 @@
+const path = require('path');
+
+module.exports = {
+  preset: 'jest-expo',
+  setupFilesAfterEnv: ['<rootDir>/jest.setup.js'],
+  moduleNameMapper: {
+    '^react$': require.resolve('react'),
+    '^react/jsx-runtime$': require.resolve('react/jsx-runtime'),
+    '^react/jsx-dev-runtime$': require.resolve('react/jsx-dev-runtime'),
+    '^@testing-library/react-native$': require.resolve(
+      '@testing-library/react-native'
+    ),
+    // Match before `@/` so `@/global.css` is stubbed (Expo web styling).
+    '^.+\\.css$': '<rootDir>/jest/cssMock.js',
+    '^@/(.*)$': '<rootDir>/src/$1',
+    '^@/assets/(.*)$': '<rootDir>/assets/$1',
+    '^@callstack/react-native-brownfield$': path.join(
+      __dirname,
+      '../../packages/react-native-brownfield/src/index.ts'
+    ),
+    '^@callstack/brownfield-navigation$': path.join(
+      __dirname,
+      '../../packages/brownfield-navigation/src/index.ts'
+    ),
+    '^@callstack/brownie$': path.join(
+      __dirname,
+      '../../packages/brownie/src/index.ts'
+    ),
+  },
+  transformIgnorePatterns: [
+    'node_modules/(?!((jest-)?react-native|@react-native(-community)?|@callstack/brownfield-example-shared-tests|expo|@expo|expo-modules-core)/)',
+  ],
+};

apps/ExpoApp55/jest.setup.js

@@ -0,0 +1 @@
+require('@callstack/brownfield-example-shared-tests/jest/setup');

apps/ExpoApp55/jest/cssMock.js

@@ -0,0 +1,2 @@
+/** Stub CSS imports for Jest (used by Expo Router / bundler pipeline). */
+module.exports = {};

apps/ExpoApp55/package.json

@@ -7,7 +7,8 @@
     "android": "expo run:android",
     "ios": "expo run:ios",
     "web": "expo start --web",
-    "lint": "expo lint",
+    "lint": "expo lint --no-cache",
+    "test": "jest --config jest.config.js",
     "prebuild": "expo prebuild",
     "brownfield:prepare:android:ci": "cd .. && node --experimental-strip-types --no-warnings ./scripts/prepare-android-build-gradle-for-ci.ts ExpoApp55",
     "brownfield:package:android": "brownfield package:android --module-name brownfieldlib --variant release",
@@ -46,9 +47,15 @@
     "react-native-worklets": "0.7.2"
   },
   "devDependencies": {
+    "@callstack/brownfield-example-shared-tests": "workspace:^",
+    "@testing-library/react-native": "^13.3.3",
+    "@types/jest": "^30.0.0",
     "@types/react": "~19.2.10",
     "eslint": "^9.25.0",
     "eslint-config-expo": "~55.0.0",
+    "jest": "^29.7.0",
+    "jest-expo": "~55.0.0",
+    "react-test-renderer": "19.2.0",
     "typescript": "~5.9.2"
   },
   "private": true,

apps/RNApp/__tests__/App.test.tsx

@@ -2,9 +2,8 @@
  * @format
  */
 
-import React from 'react';
 import ReactTestRenderer from 'react-test-renderer';
-import App from '../App';
+import App from '../src/App';
 
 test('renders correctly', async () => {
   await ReactTestRenderer.act(() => {

apps/RNApp/__tests__/brownfield.example.test.tsx

@@ -0,0 +1,12 @@
+import {
+  runCounterSuite,
+  runHomeScreenSuite,
+} from '@callstack/brownfield-example-shared-tests';
+import { HomeScreen } from '../src/HomeScreen';
+import Counter from '../src/components/counter';
+import { getRandomTheme } from '../src/utils';
+
+const theme = getRandomTheme();
+
+runHomeScreenSuite('RNApp', HomeScreen);
+runCounterSuite('RNApp', Counter, { colors: theme });

apps/RNApp/jest.config.js

@@ -1,3 +1,28 @@
+const path = require('node:path');
+
 module.exports = {
   preset: '@react-native/jest-preset',
+  setupFilesAfterEnv: ['<rootDir>/jest.setup.js'],
+  moduleNameMapper: {
+    '^react$': require.resolve('react'),
+    '^react/jsx-runtime$': require.resolve('react/jsx-runtime'),
+    '^react/jsx-dev-runtime$': require.resolve('react/jsx-dev-runtime'),
+    '^@testing-library/react-native$':
+      require.resolve('@testing-library/react-native'),
+    '^@callstack/react-native-brownfield$': path.join(
+      __dirname,
+      '../../packages/react-native-brownfield/src/index.ts'
+    ),
+    '^@callstack/brownfield-navigation$': path.join(
+      __dirname,
+      '../../packages/brownfield-navigation/src/index.ts'
+    ),
+    '^@callstack/brownie$': path.join(
+      __dirname,
+      '../../packages/brownie/src/index.ts'
+    ),
+  },
+  transformIgnorePatterns: [
+    'node_modules/(?!((jest-)?react-native|@react-native(-community)?|@callstack/brownfield-example-shared-tests|@react-navigation|react-native-screens|react-native-safe-area-context)/)',
+  ],
 };

apps/RNApp/jest.setup.js

@@ -0,0 +1 @@
+require('@callstack/brownfield-example-shared-tests/jest/setup');

apps/RNApp/package.json

@@ -12,7 +12,7 @@
     "brownfield:package:ios": "brownfield package:ios --scheme BrownfieldLib --configuration Release",
     "lint": "eslint .",
     "start": "react-native start",
-    "test": "jest",
+    "test": "jest --config jest.config.js",
     "codegen": "brownfield codegen",
     "codegen:navigation": "brownfield navigation:codegen brownfield.navigation.ts"
   },
@@ -31,6 +31,7 @@
     "@babel/core": "^7.25.2",
     "@babel/preset-env": "^7.25.3",
     "@babel/runtime": "^7.25.0",
+    "@callstack/brownfield-example-shared-tests": "workspace:^",
     "@react-native-community/cli": "20.1.0",
     "@react-native-community/cli-platform-android": "20.1.0",
     "@react-native-community/cli-platform-ios": "20.1.0",
@@ -39,6 +40,7 @@
     "@react-native/jest-preset": "0.85.0",
     "@react-native/metro-config": "0.85.0",
     "@react-native/typescript-config": "0.85.0",
+    "@testing-library/react-native": "^13.3.3",
     "@types/jest": "^30.0.0",
     "@types/react": "^19.2.0",
     "@types/react-test-renderer": "^19.1.0",

apps/brownfield-example-shared-tests/jest/setup.js

@@ -0,0 +1,56 @@
+/**
+ * Shared Jest setup for brownfield example apps. Include via setupFilesAfterEnv.
+ *
+ * @see https://jestjs.io/docs/configuration#setupfilesafterenv-array
+ */
+
+global.__brownieExampleCounter = 0;
+global.__resetBrownieExampleStore = () => {
+  global.__brownieExampleCounter = 0;
+};
+
+jest.mock('@callstack/react-native-brownfield', () => ({
+  __esModule: true,
+  default: {
+    onMessage: jest.fn(() => ({ remove: jest.fn() })),
+    postMessage: jest.fn(),
+    setNativeBackGestureAndButtonEnabled: jest.fn(),
+    popToNative: jest.fn(),
+  },
+}));
+
+jest.mock('@callstack/brownfield-navigation', () => ({
+  __esModule: true,
+  default: {
+    navigateToSettings: jest.fn(),
+    navigateToReferrals: jest.fn(),
+  },
+}));
+
+jest.mock('@callstack/brownie', () => ({
+  __esModule: true,
+  /** Resolve React from the app running Jest (cwd), not from this package's nested deps. */
+  useStore(key, selector) {
+    const React = require(require.resolve('react', { paths: [process.cwd()] }));
+    const [, setRev] = React.useState(0);
+    const setState = React.useCallback(
+      (action) => {
+        const prev = { counter: global.__brownieExampleCounter };
+        const partial = typeof action === 'function' ? action(prev) : action;
+        if (
+          partial &&
+          typeof partial === 'object' &&
+          partial.counter !== undefined
+        ) {
+          global.__brownieExampleCounter = partial.counter;
+        }
+        setRev((r) => r + 1);
+      },
+      [selector]
+    );
+    return [
+      selector({ counter: global.__brownieExampleCounter }),
+      setState,
+    ];
+  },
+}));

apps/brownfield-example-shared-tests/package.json

@@ -0,0 +1,28 @@
+{
+  "name": "@callstack/brownfield-example-shared-tests",
+  "version": "0.0.1",
+  "private": true,
+  "scripts": {
+    "test": "node -e \"process.exit(0)\""
+  },
+  "main": "src/index.ts",
+  "types": "src/index.ts",
+  "exports": {
+    ".": "./src/index.ts",
+    "./jest/setup": "./jest/setup.js"
+  },
+  "peerDependencies": {
+    "@testing-library/react-native": ">=12",
+    "react": ">=18",
+    "react-native": ">=0.73",
+    "react-test-renderer": ">=18"
+  },
+  "devDependencies": {
+    "@callstack/brownfield-navigation": "workspace:^",
+    "@callstack/react-native-brownfield": "workspace:^",
+    "@testing-library/react-native": "^13.3.3",
+    "@types/jest": "^30.0.0",
+    "@types/react": "^19.1.1",
+    "typescript": "5.9.3"
+  }
+}

apps/brownfield-example-shared-tests/src/global.d.ts

@@ -0,0 +1,7 @@
+/* eslint-disable no-var */
+declare global {
+  var __brownieExampleCounter: number;
+  var __resetBrownieExampleStore: () => void;
+}
+
+export {};

apps/brownfield-example-shared-tests/src/index.ts

@@ -0,0 +1,4 @@
+export { runPostMessageTabSuite } from './suites/postMessageTab.suite';
+export { runCounterSuite } from './suites/counter.suite';
+export { runExpoRnAppSuite } from './suites/expoRnApp.suite';
+export { runHomeScreenSuite } from './suites/homeScreen.suite';