jubakitiashvili/everything-react-native-expo/native-module-scaffold

npx create-expo-module my-module

modules/my-module/
  expo-module.config.json
  src/MyModuleModule.ts          # TypeScript API
  ios/MyModuleModule.swift        # Swift implementation
  android/src/.../MyModuleModule.kt  # Kotlin implementation
  src/__tests__/MyModule.test.ts

// NativeMyModule.ts
import type { TurboModule } from 'react-native';
import { TurboModuleRegistry } from 'react-native';
export interface Spec extends TurboModule {
  multiply(a: number, b: number): Promise<number>;
  getDeviceInfo(): { model: string; os: string; version: string };
}
export default TurboModuleRegistry.getEnforcing<Spec>('MyModule');

@objc(MyModule)
class MyModule: NSObject {
  @objc func multiply(_ a: Double, b: Double, resolve: @escaping RCTPromiseResolveBlock, reject: @escaping RCTPromiseRejectBlock) {
    resolve(a * b)
  }
 
  @objc func getDeviceInfo() -> [String: String] {
    return [
      "model": UIDevice.current.model,
      "os": UIDevice.current.systemName,
      "version": UIDevice.current.systemVersion
    ]
  }
}

class MyModuleModule(reactContext: ReactApplicationContext) :
  NativeMyModuleSpec(reactContext) {
 
  override fun multiply(a: Double, b: Double): Promise {
    return Promise.resolve(a * b)
  }
 
  override fun getDeviceInfo(): WritableMap {
    return Arguments.createMap().apply {
      putString("model", Build.MODEL)
      putString("os", "Android")
      putString("version", Build.VERSION.RELEASE)
    }
  }
}

// NativeMyView.ts
import type { ViewProps } from 'react-native';
import codegenNativeComponent from 'react-native/Libraries/Utilities/codegenNativeComponent';
interface NativeProps extends ViewProps {
  color?: string;
  radius?: number;
}
export default codegenNativeComponent<NativeProps>('MyView');