E044 - Herst/bootlint-ng GitHub Wiki
Note: Below is the original page from the Bootlint documentation, some of the info here might not apply to Bootlint-NG!
.input-groups must contain at least two children, one of which must be a .form-control and the other of which must be an .input-group-addon or an .input-group-btn. Otherwise, it doesn't make sense to even use an .input-group.
Wrong:
<div class="input-group">
<input type="text" class="form-control" placeholder="Username">
</div>Right:
<div class="input-group">
<span class="input-group-addon" id="basic-addon1">@</span>
<input type="text" class="form-control" placeholder="Username" aria-describedby="basic-addon1">
</div>Also Right:
<div class="input-group">
<input type="text" class="form-control" placeholder="Search for...">
<span class="input-group-btn">
<button class="btn btn-default" type="button">Go!</button>
</span>
</div>