title: uisng multer with typescript: Property 'file' does not exist on type 'Request'.ts(2339)
body: <p>I am using <a href="https://www.npmjs.com/package/multer" rel="noreferrer">https://www.npmjs.com/package/multer</a> library and my node.js app is written in typescript.</p>
  
  <p>I get the following typescript error in my code.</p>
  
  <blockquote>
    <p>Property 'file' does not exist on type 'Request'.ts(2339)</p>
  </blockquote>
  
  <pre><code>    public document = async (req: Request, res: Response): Promise&lt;any&gt; =&gt; {
          const documentFile = req.file;
      }
  </code></pre>
  
  <p>How can i resolve this. The req is the express Request object but multers middleware appends a .file into this request object. However it is not aware of this because the types request interface does not originally contain a file properly</p>