Also you can use ui-sref-active directive:
<ul>
<li ui-sref-active="active" class="item">
<a href ui-sref="app.user({user: 'bilbobaggins'})">@bilbobaggins</a>
</li>
<!-- ... -->
</ul>
Or filters:
"stateName" | isState
& "stateName" | includedByState