title: Unexpected end of JSON on GraphQL query with React while no issue with GraphiQL
body: <p>I am trying to do a very basic query via React with Apollo.</p>
  
  <p>When I do this query in GraphiQL I nicely get my results back but in my app I get an undefined data object. And a error with a message: </p>
  
  <blockquote>
    <p>Network error: Unexpected end of JSON input</p>
  </blockquote>
  
  <p>The query is:</p>
  
  <pre><code>query {
      category(id: 3) {
          id
          children {
              id
              name
          }
      }
  }
  </code></pre>
  
  <p>This is my component</p>
  
  <pre><code>import React, { Component } from 'react';
  import { Query } from 'react-apollo';
  import gql from 'graphql-tag';
  
  const CATEGORIES_LIST = gql`
      query CATEGORIES_LIST {
          category(id: 3) {
              id
              children {
                  id
                  name
              }
          }
      }
  `;
  
  class Cat extends Component {
      render() {
          return (
              &lt;div&gt;
                  &lt;p&gt;Items!&lt;/p&gt;
                  &lt;Query query={CATEGORIES_LIST}&gt;
                      {payload =&gt; {
                          console.log(payload);
                          return &lt;p&gt;fetch done!&lt;/p&gt;;
                      }}
                  &lt;/Query&gt;
              &lt;/div&gt;
          )
      }
  }
  
  export default Cat;
  </code></pre>
  
  <p>While the GraphiQL response is with the exact same request</p>
  
  <pre><code>{
    "data": {
      "category": {
        "id": 3,
        "children": [
          {
            "id": 4,
            "name": "Bags"
          },
          {
            "id": 5,
            "name": "Fitness Equipment"
          },
          {
            "id": 6,
            "name": "Watches"
          }
        ]
      }
    }
  }
  </code></pre>
  
  <p>By the way I'm querying a local Magento 2.3 graphql server.</p>
  
  <p>When inspecting the network tab this is the response i get from the graphql endpoint. So no url typo are issue in the response</p>
  
  <pre><code>{
     "data":{
        "category":{
           "id":3,
           "children":[
              {
                 "id":4,
                 "name":"Bags",
                 "__typename":"CategoryTree"
              },
              {
                 "id":5,
                 "name":"Fitness Equipment",
                 "__typename":"CategoryTree"
              },
              {
                 "id":6,
                 "name":"Watches",
                 "__typename":"CategoryTree"
              }
           ],
           "__typename":"CategoryTree"
        }
     }
  }
  </code></pre>