Get data from express with fetch
<p>I try to <code>alert</code> string which is variable in express.get and do to res. I wanna get in alert this "I am working fetch".</p>

<p>Here my <strong>server.js</strong></p>

<pre><code>var express = require('express');
var app = express();

app.use(express.static(__dirname + '/publicServer'));

app.get('/fimlList', function(req, res) {
  console.log('i receive a GET request');

  var tryFetch = {myString: 'I am working fetch'};

  res.json(tryFetch)
})

app.listen(3000);
console.log('Server running on port 3000');
</code></pre>

<p>my <strong>App.js</strong></p>

<pre><code>import React from 'react';

var IchBinForm = require('./IchBinForm');
var SortFilms = require('./SortFilms');
var SearchFilm = require('./SearchFilm');
var FilmShort = require('./FilmShort.js');
var FilmLong = require('./FilmLong.js');

var App = React.createClass({
  getInitialState: function() {
    return {
      list: {}
  },

  componentWillMount: function(){
    var fromServer = fetch('/fimlList')
    .then(function(response) {
      return response.json()
    })
    .then(function(responseJson) {

      return responseJson.myString
    })

    alert(fromServer);

  },

changeShow: function(newShow, filmId) {...},    
  deleteFilm: function(id) {...},    
  seeForChangeInForm: function(change, id) {...},    
  addNewFilm: function() {...},   
  sortMe:function() {...},    
  searchMe: function(searchWord) {...},    
  howSearch:function(whichCheckBox, val) {...},

  render: function() {

    ....
        }
      }

    });

    return (...);
  }
});

module.exports = App;
</code></pre>

<p>and what I get:</p>

<p><a href="https://i.stack.imgur.com/tz97C.png" rel="noreferrer"><img src="https://i.stack.imgur.com/tz97C.png" alt="My alert now"></a></p>

<p>What do I do wrong ?</p>