rn_firebase_analytics_app.js

import React, { Component } from 'react';
import {
  Platform,
  StyleSheet,
  Text,
  View,
  Button
} from 'react-native';
import firebase from 'react-native-firebase';
const firebaseAnalytics = firebase.analytics();

export default class App extends Component<{}> {
  onPressComprar(){
    console.log('Boton comprar presionado');
  };

  render() {
    return (
      <View style={styles.container}>
        <Text style={styles.welcome}>
          React Native Firebase!
        </Text>
        <Button
          onPress={this.onPressComprar}
          title="Cromprar"
          color="#841584"
        />
      </View>
    );
  }
}

const styles = StyleSheet.create({
  container: {
    flex: 1,
    justifyContent: 'center',
    alignItems: 'center',
    backgroundColor: '#F5FCFF',
  },
  welcome: {
    fontSize: 20,
    textAlign: 'center',
    margin: 10,
  }
});