metro.config.js

const {getDefaultConfig: getExpoDefaultConfig} = require('expo/metro-config');
const {getDefaultConfig: getReactNativeDefaultConfig} = require('@react-native/metro-config');

const {mergeConfig} = require('@react-native/metro-config');
const {wrapWithReanimatedMetroConfig} = require('react-native-reanimated/metro-config');
const {withSentryConfig} = require('@sentry/react-native/metro');
const {createSentryMetroSerializer} = require('@sentry/react-native/dist/js/tools/sentryMetroSerializer');

const path = require('path');

// Prefer explicit ENVFILE (Fastlane/GHA set this), else fall back to local .env
const envPath = process.env.ENVFILE ? (path.isAbsolute(process.env.ENVFILE) ? process.env.ENVFILE : path.join(__dirname, process.env.ENVFILE)) : path.join(__dirname, '.env');
require('dotenv').config({path: envPath});

const defaultConfig = getReactNativeDefaultConfig(__dirname);
const expoConfig = getExpoDefaultConfig(__dirname);

const isDev = process.env.ENVIRONMENT === undefined || process.env.ENVIRONMENT === 'development';

/**
 * Metro configuration
 * https://reactnative.dev/docs/metro
 *
 * @type {import('metro-config').MetroConfig}
 */
const defaultGetPolyfills = defaultConfig.serializer?.getPolyfills ?? (() => []);

const config = {
    resolver: {
        assetExts: [...defaultConfig.resolver.assetExts, 'lottie'],
        sourceExts: [...defaultConfig.resolver.sourceExts, ...defaultConfig.watcher.additionalExts, 'jsx'],
    },
    // We are merging the default config from Expo and React Native and expo one is overriding the React Native one so inlineRequires is set to false so we want to set it to true
    // for fix cycling dependencies and improve performance of app startup
    transformer: {
        getTransformOptions: async () => ({
            transform: {
                experimentalImportSupport: true,
                inlineRequires: true,
            },
        }),
    },
    serializer: {
        getPolyfills: (opts) => [...defaultGetPolyfills(opts), path.resolve(__dirname, 'src/setup/moduleInitPolyfill.ts')],
        ...(!isDev ? {customSerializer: createSentryMetroSerializer()} : {}),
    },
};

const mergedConfig = wrapWithReanimatedMetroConfig(mergeConfig(defaultConfig, expoConfig, config));

module.exports = isDev ? mergedConfig : withSentryConfig(mergedConfig);