title: Type '{}' is not assignable to type 'Readonly<HelloProps>'
body: <p>I'm trying to inject to stores into a component, but it seems that it's not working.<br>
  Here is the class</p>
  
  <pre><code>import * as React from 'react';
  import { inject, observer } from 'mobx-react';
  
  import { FlightStore } from '../stores/FlightStore';
  
  export interface HelloProps {
     flightStore: FlightStore
  }
  
  
  
  @inject('flightStore')
  @observer
  class Hello extends React.Component&lt;HelloProps, any&gt; {
  
  constructor(props: HelloProps) {
      super(props);
      this.state = {
          //
      }
  }
  
  
  componentWillMount() {
      this.props.flightStore.getData();
  }
  
  render() {
      return (
          &lt;div&gt;
  
          &lt;/div&gt;
      )
  }
  }
  
  export default Hello;
  </code></pre>
  
  <p>It says <code>Type '{}' is not assignable to type 'Readonly&lt;HelloProps&gt;'.
    Property 'flightStore' is missing in type '{}'</code>, it confuses me because I'm not declaring any data type anywhere so I don't know what's happening.</p>
  
  <p>Here is the store</p>
  
  <pre><code>import { action, observable } from 'mobx';
  import *  as $ from 'jquery' ;
  
  
  export class FlightStore {
  
  @observable dataJ: any;
  
  constructor() {
      //
  }
  
  @action getData() {
  
      $.ajax({
          url: 'https://www.kayak.com/h/mobileapis/directory/airlines',
          dataType: 'json',
          cache: false,
          success: (data: any) =&gt; {
              this.dataJ = data;
              console.log(data)
          },
          error: (xhr: any, status: any, err: any) =&gt; {
              console.log(err);
          }
      })
      console.log('I´m in getData')
  }
  
  }
  </code></pre>
  
  <p>It's strange because when I try to put "?" in the class</p>
  
  <pre><code>export interface HelloProps {
    flightStore?: FlightStore
  }
  </code></pre>
  
  <p>it says that this this.props.flightStore => <code>[ts] Object is possibly 'undefined'.</code> in ComponentWillMount()</p>
  
  <h2>Update</h2>
  
  <p>And yes the error happens when I try to use <code>&lt;Hello/&gt;</code> component without passing props, because I'm using Mobx.<br>
  The index app</p>
  
  <pre><code>import * as React from 'react';
  import Hello from './components/Hello';
  
  import stores from './stores'; 
  import { Provider } from 'mobx-react';
  
  
   export default class App extends React.Component {
   render() {
      return (
          &lt;Provider {...stores}&gt;
              &lt;div&gt;
                  &lt;Hello /&gt;
              &lt;/div&gt;
          &lt;/Provider&gt;
      );
    }
  }
  </code></pre>