Firebase.js

// @flow
export default class FirebaseUtils {
  static logEvent(name: string, parameters: Object = {}): void {
    if (!name) {
      return
    }

    if (FirebaseUtils.isAndroid) {
      window.AnalyticsWebInterface.logEvent(name, JSON.stringify(parameters))
      return
    }

    if (FirebaseUtils.isIOS) {
      const command = 'logEvent'
      window.webkit.messageHandlers.firebase.postMessage({ command, name, parameters })
    }
  }

  static get isAndroid(): boolean {
    return !!window.AnalyticsWebInterface
  }

  static get isIOS(): boolean {
    return window.webkit && window.webkit.messageHandlers && window.webkit.messageHandlers.firebase
  }
}