Migrating from version 2.x/3.x to 4.x

Version 3.x of react-native-camera replaces MLKit for Firebase(which has been deprecated) with Google MLKit, allowing you to use advanced features such as text/face recognition without Firebase. You can learn more at MLKit

Required steps

Skip this if you need Firebase in your project

Remove Firebase project

Android

Remove the Firebase configuration file by deleting the google-services.json config file at android/app/.
Replace the Google Services Gradle plugin classpath in android/app/build.gradle with the one for the Strict Version Matcher plugin:

    buildscript {
      dependencies {
        // Add this line
-       classpath 'com.google.gms:google-services:4.0.1' <-- you might want to use different version
+       classpath 'com.google.android.gms:strict-version-matcher-plugin:1.2.1'
      }
    }

Replace the Google Services Gradle plugin in android/build.gradle with the Strict Version Matcher plugin:

- apply plugin: 'com.google.gms.google-services'
+ apply plugin: 'com.google.android.gms.strict-version-matcher-plugin'

Remove meta fron android/app/Manifest.xml(MLKit use bundled models)

<application ...>
...
- <meta-data
-     android:name="com.google.firebase.ml.vision.DEPENDENCIES"
-     android:value="ocr" />
- <!-- To use multiple models, list all needed models: android:value="ocr, face, barcode" -->
</application>

iOS

Remove GoogleService-Info.plist from your project
Remove pod 'Firebase/Core' from your Podfile

1\3. Remove Firebase code from AppDelegate.m

-#import <Firebase.h> // <--- add this
...

\- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
- [FIRApp configure]; // <--- add this
  ...
}