App.js

/**
 * Sample React Native App
 * https://github.com/facebook/react-native
 *
 * @format
 * @flow
 */

import React, {Component} from 'react';
import {Platform, StyleSheet, Text, View, Button} from 'react-native';

import request from 'axios';

const instructions = Platform.select({
  ios: 'Press Cmd+R to reload,\n' + 'Cmd+D or shake for dev menu',
  android:
    'Double tap R on your keyboard to reload,\n' +
    'Shake or press menu button for dev menu',
});

type Props = {};
export default class App extends Component<Props> {
  _checkConnectivity = () => {
    console.log('calling')
    request
      .post('https://localhost:3000')
      .then( response => {
        console.log(response);
      })
      .catch(error => {
        console.log(error)
        if (error.response) {
          console.log(1)
          console.log(error.response.data);
          console.log(error.response.status);
          console.log(error.response.headers);
        } else if (error.request) {
          console.log(2)
          console.log(error.request);
        } else {
          console.log(3)
          console.log('Error', error.message);
        }
        console.log(error.config);
      });
  }

  render() {
    return (
      <View style={styles.container}>
        <Text style={styles.welcome}>Welcome to React Native!</Text>
        <Text style={styles.instructions}>To get started, edit App.js</Text>
        <Text style={styles.instructions}>{instructions}</Text>
        <Button title="Hey call" onPress={this._checkConnectivity}></Button>
      </View>
    );
  }
}

const styles = StyleSheet.create({
  container: {
    flex: 1,
    justifyContent: 'center',
    alignItems: 'center',
    backgroundColor: '#F5FCFF',
  },
  welcome: {
    fontSize: 20,
    textAlign: 'center',
    margin: 10,
  },
  instructions: {
    textAlign: 'center',
    color: '#333333',
    marginBottom: 5,
  },
});