title: Using assert_select to find a select box value?
body: <p>I'm struggling to test whether my select box has a value of 6.</p>
  
  <pre><code>&lt;form class="edit_line_item" id="edit_line_item_7" action="/line_items/7" accept-charset="UTF-8" method="post"&gt;&lt;input name="utf8" type="hidden" value="✓"&gt;&lt;input type="hidden" name="_method" value="patch"&gt;
      &lt;select name="line_item[quantity]" id="line_item_quantity"&gt;&lt;option selected="selected" value="1"&gt;1&lt;/option&gt;
      &lt;/select&gt;
  &lt;/form&gt;
  </code></pre>
  
  <p>My rspec code</p>
  
  <pre><code>assert_select "select#line_item_quantity", value: 6
  </code></pre>
  
  <p>Whatever I change the value to my test still passes so I am wrong somewhere.</p>