UnusedAssign flags variables used in assigns as unused

[charlespwd]

This shouldn't trigger an UnusedAssign:

{% assign format = 'jpeg' %}
{% assign url = product.featured_image | image_url: width: 800, format: format %}

[charlespwd]

Unit test passes. Don't know what was up. Must have been something else.

[eloyesp]

This fails when the assigns is within a conditional:

    {% assign checked = false %}
    {% if option.selected_value == value %}
      {% assign checked = true %} <!--here it fails -->
    {% endif %}
    {% render 'swatch-input', checked: checked %}