react-native-vision-camera/package/src/CameraDevices.ts

import { NativeModules, NativeEventEmitter } from 'react-native';
import { CameraDevice } from './CameraDevice';

const CameraDevicesManager = NativeModules.CameraDevices as {
  getConstants: () => {
    availableCameraDevices: CameraDevice[];
    userPreferredCameraDevice: CameraDevice | undefined;
  };
};

const constants = CameraDevicesManager.getConstants();
let devices = constants.availableCameraDevices;

const DEVICES_CHANGED_NAME = 'CameraDevicesChanged';
// eslint-disable-next-line @typescript-eslint/no-explicit-any
const eventEmitter = new NativeEventEmitter(CameraDevicesManager as any);
eventEmitter.addListener(DEVICES_CHANGED_NAME, (newDevices: CameraDevice[]) => {
  devices = newDevices;
});

export const CameraDevices = {
  userPreferredCameraDevice: constants.userPreferredCameraDevice,
  getAvailableCameraDevices: () => devices,
  addCameraDevicesChangedListener: (callback: (newDevices: CameraDevice[]) => void) => {
    return eventEmitter.addListener(DEVICES_CHANGED_NAME, callback);
  },
};