title: Access Properties of a generic type
body: <p>I am building a generic filter hook in React with Typescript
  The hook has a generic, as a slot for the respective Filter Type (complex type).</p>
  <p>As a property the hook gets a string array for the filterable fields, which correspond to the property keys of the generic.</p>
  <p>During runtime I want to check the type of the property. As generic types do not exist during runtime I cannot access the property and its type with the [].</p>
  <p>Is there any way to check the type of a generic types property without passing an object?</p>
  <pre><code>export type Filterable = {
    label: string;
    filterTypeEntry?: string;
  };
  export default &lt;FilterType&gt;(filterable?: Filterable[]) =&gt; { 
  //I want to check if FilterType contains a property with the key equals to the filterTypeEntry
  }
  </code></pre>