fix: make sure lib are loaded for expo apps (#322)

* fix: make sure android libs are loaded for expo apps

* docs: clean up chapter 4 and mention one ReactNativeBrownfield::initialize variant is deprecated

Author: marcinszalski-callstack

.changeset/five-signs-fix.md

@@ -0,0 +1,7 @@
+---
+'@callstack/react-native-brownfield': patch
+'@callstack/brownfield-navigation': patch
+'@callstack/brownie': patch
+---
+
+fix: make sure android libs are loaded for expo apps

apps/RNApp/android/BrownfieldLib/consumer-rules.pro

@@ -185,14 +185,17 @@ import com.facebook.react.ReactNativeApplicationEntryPoint.loadReactNative
 
 object ReactNativeHostManager {
     fun initialize(application: Application, onJSBundleLoaded: OnJSBundleLoaded? = null) {
-        loadReactNative(application) // **Only required for RN >= 0.80.0**
-
         val packageList = PackageList(application).packages
         ReactNativeBrownfield.initialize(application, packageList, onJSBundleLoaded)
     }
 }
 ```
 
+:::warning Important
+The `ReactNativeBrownfield::initialize(Application, ReactHost, OnJSBundleLoaded? = null)` function variant is deprecated and shouldn't be used any more. It will be removed in a future release.
+This version is unsafe because passing a pre-constructed `ReactHost` can trigger `SoLoader` (e.g., via `ExpoReactHostFactory`) before native libraries are fully loaded, leading to potential runtime crashes.
+:::
+
 ## 5. Add Build Config Fields
 
 Add to `reactnativeapp/build.gradle.kts`:

docs/docs/docs/getting-started/android.mdx

@@ -66,15 +66,15 @@
     "@babel/core": "^7.25.2",
     "@babel/preset-env": "^7.25.3",
     "@babel/runtime": "^7.25.0",
-    "@react-native/babel-preset": "0.82.1",
+    "@react-native/babel-preset": "0.83.2",
     "@types/jest": "^30.0.0",
     "@types/react": "^19.1.1",
     "eslint": "^9.28.0",
     "globals": "^16.2.0",
     "import": "^0.0.6",
     "nodemon": "^3.1.14",
     "react": "19.1.1",
-    "react-native": "0.82.1",
+    "react-native": "0.83.2",
     "react-native-builder-bob": "^0.41.0",
     "typescript": "5.9.3"
   },

packages/brownfield-navigation/package.json

@@ -84,15 +84,15 @@
     "@babel/preset-env": "^7.25.3",
     "@babel/preset-typescript": "^7.27.1",
     "@babel/runtime": "^7.25.0",
-    "@react-native/babel-preset": "0.82.1",
-    "@react-native/eslint-config": "0.82.1",
+    "@react-native/babel-preset": "0.83.2",
+    "@react-native/eslint-config": "0.83.2",
     "@types/node": "^25.5.0",
     "@types/react": "^19.1.1",
     "eslint": "^9.39.3",
     "globals": "^17.3.0",
     "import": "^0.0.6",
     "nodemon": "^3.1.14",
-    "react-native": "0.82.1",
+    "react-native": "0.83.2",
     "react-native-builder-bob": "^0.41.0",
     "typescript": "5.9.3"
   },

packages/brownie/package.json

@@ -34,7 +34,6 @@ class ReactNativeBrownfield private constructor(val reactHost: ReactHost) {
         private lateinit var instance: ReactNativeBrownfield
         private val initialized = AtomicBoolean()
         private val nativeLibsLoaded = AtomicBoolean()
-        private const val LOG_TAG = "ReactNativeBrownfield"
 
         @JvmStatic
         val shared: ReactNativeBrownfield get() = instance
@@ -50,6 +49,12 @@ class ReactNativeBrownfield private constructor(val reactHost: ReactHost) {
             load()
         }
 
+        @Deprecated(
+            message = "Unsafe when reactHost construction triggers SoLoader (e.g. ExpoReactHostFactory): " +
+                "the parameter is evaluated by the caller before loadNativeLibs() runs. " +
+                "Use initialize(application, onJSBundleLoaded) { reactHostFactory } instead.",
+            replaceWith = ReplaceWith("initialize(application, onJSBundleLoaded) { reactHost }")
+        )
         @JvmStatic
         @JvmOverloads
         fun initialize(
@@ -59,25 +64,32 @@ class ReactNativeBrownfield private constructor(val reactHost: ReactHost) {
         ) {
             if (!initialized.getAndSet(true)) {
                 loadNativeLibs(application)
-                instance = ReactNativeBrownfield(reactHost)
-
-                preloadReactNative {
-                    onJSBundleLoaded?.invoke(true)
-                }
+                installAndPreload(reactHost, onJSBundleLoaded)
             }
         }
 
+        @JvmStatic
+        fun initialize(
+            application: Application,
+            onJSBundleLoaded: OnJSBundleLoaded? = null,
+            reactHostFactory: () -> ReactHost
+        ) {
+            if (!initialized.getAndSet(true)) {
+                loadNativeLibs(application)
+                installAndPreload(reactHostFactory(), onJSBundleLoaded)
+            }
+        }
+        
         @JvmStatic
         @JvmOverloads
         fun initialize(
             application: Application,
             options: HashMap<String, Any>,
             onJSBundleLoaded: OnJSBundleLoaded? = null
         ) {
-            loadNativeLibs(application)
-
-            val reactHost: ReactHost by lazy {
-                getDefaultReactHost(
+            if (!initialized.getAndSet(true)) {
+                loadNativeLibs(application)
+                val reactHost = getDefaultReactHost(
                     context = application,
                     packageList = (options["packages"] as? List<*> ?: emptyList<ReactPackage>())
                         .filterIsInstance<ReactPackage>(),
@@ -89,9 +101,8 @@ class ReactNativeBrownfield private constructor(val reactHost: ReactHost) {
                         ?: ReactBuildConfig.DEBUG,
                     jsRuntimeFactory = null
                 )
+                installAndPreload(reactHost, onJSBundleLoaded)
             }
-
-            initialize(application, reactHost, onJSBundleLoaded)
         }
 
         @JvmStatic
@@ -116,6 +127,13 @@ class ReactNativeBrownfield private constructor(val reactHost: ReactHost) {
             })
             shared.reactHost.start()
         }
+
+        private fun installAndPreload(reactHost: ReactHost, onJSBundleLoaded: OnJSBundleLoaded?) {
+            instance = ReactNativeBrownfield(reactHost)
+            preloadReactNative {
+                onJSBundleLoaded?.invoke(true)
+            }
+        }
     }
 
     /**

packages/react-native-brownfield/android/src/main/java/com/callstack/reactnativebrownfield/ReactNativeBrownfield.kt

@@ -93,7 +93,7 @@
     "@babel/preset-env": "^7.25.3",
     "@babel/runtime": "^7.25.0",
     "@expo/config-plugins": "^54.0.4",
-    "@react-native/babel-preset": "0.82.1",
+    "@react-native/babel-preset": "0.83.2",
     "@types/jest": "^30.0.0",
     "@types/react": "^19.1.1",
     "@vitest/coverage-v8": "^4.1.0",
@@ -102,7 +102,7 @@
     "import": "^0.0.6",
     "nodemon": "^3.1.14",
     "react": "19.1.1",
-    "react-native": "0.82.1",
+    "react-native": "0.83.2",
     "react-native-builder-bob": "^0.41.0",
     "typescript": "5.9.3",
     "vitest": "^4.1.4"

packages/react-native-brownfield/package.json

@@ -5,22 +5,19 @@ import android.content.res.Configuration
 import com.callstack.reactnativebrownfield.OnJSBundleLoaded
 import com.callstack.reactnativebrownfield.ReactNativeBrownfield
 import com.facebook.react.PackageList
-import com.facebook.react.ReactHost
 import expo.modules.ApplicationLifecycleDispatcher
 import expo.modules.ExpoReactHostFactory
 
 object ReactNativeHostManager {
     fun initialize(application: Application, onJSBundleLoaded: OnJSBundleLoaded? = null) {
         ApplicationLifecycleDispatcher.onApplicationCreate(application)
 
-        val reactHost: ReactHost by lazy {
+        ReactNativeBrownfield.initialize(application, onJSBundleLoaded) {
             ExpoReactHostFactory.getDefaultReactHost(
                 context = application.applicationContext,
                 packageList = PackageList(application).packages,
             )
         }
-
-        ReactNativeBrownfield.initialize(application, reactHost, onJSBundleLoaded)
     }
 
     fun onConfigurationChanged(application: Application, newConfig: Configuration) {

packages/react-native-brownfield/src/expo-config-plugin/template/android/ReactNativeHostManager.post55.kt

@@ -5,7 +5,6 @@ import android.content.res.Configuration
 import com.callstack.reactnativebrownfield.OnJSBundleLoaded
 import com.callstack.reactnativebrownfield.ReactNativeBrownfield
 import com.facebook.react.PackageList
-import com.facebook.react.ReactHost
 import com.facebook.react.ReactPackage
 import com.facebook.react.defaults.DefaultReactNativeHost
 import expo.modules.ApplicationLifecycleDispatcher
@@ -34,15 +33,12 @@ object ReactNativeHostManager {
                 override fun getBundleAssetName(): String = "index.android.bundle"
             })
 
-
-        val reactHost: ReactHost by lazy {
+        ReactNativeBrownfield.initialize(application, onJSBundleLoaded) {
             ExpoReactHostFactory.createFromReactNativeHost(
                 context = application.applicationContext,
                 reactNativeHost = reactNativeHost
             )
         }
-
-        ReactNativeBrownfield.initialize(application, reactHost, onJSBundleLoaded)
     }
 
     fun onConfigurationChanged(application: Application, newConfig: Configuration) {