title: Argument of type 'number' is not assignable to parameter of type 'number & string'
body: <p>I want to use <code>Array.prototype.includes</code> method in my ts file like.</p>
  
  <pre><code>const id = this.selectedItem.id;
  ids.includes(id);
  </code></pre>
  
  <p>Where <code>ids</code> is an array of numbers.
  I always get a compilation error:
  <code>Argument of type 'number' is not assignable to parameter of type 'number &amp; string'</code></p>
  
  <p>When explicitly transform id to be a number <code>Number(id)</code>, then I also see <code>Type number is not assignable to type string</code>.
  And when I explicitly transform id to be a string <code>id.toString()</code> then I can see <code>Type string is not assignable to type number</code>.</p>
  
  <p>It is overwhelmig. How <code>includes</code> method can be used in TypeScript? How to use it in my example?</p>
  
  <p><strong>[Edit]</strong> Extended example:</p>
  
  <pre><code>    interface State extends EntityState&lt;IItem&gt; {}
  
      this.stateSubscription = this.store.select((state: State) =&gt; state.items).subscribe(
          val =&gt; {
              const selectedId = this.selectedItem ? this.selectedItem.id : null;
              val.ids.includes(selectedId);
      }));
  </code></pre>
  
  <p><code>val.ids.includes(selectedId as any)</code> also doesn't work.</p>