--TEST--
block_expr
--TEMPLATE--
{% extends "base.twig" %}

{% block element -%}
    Element:
    {{- parent() -}}
{% endblock %}
--TEMPLATE(base.twig)--
{% block element -%}
    <div>
        {%- if item.children is defined %}
            {%- for item in item.children %}
                {{- block('element') -}}
            {% endfor %}
        {%- endif -%}
    </div>
{%- endblock %}
--DATA--
return [
    'item' => [
        'children' => [
            null,
            null,
        ]
    ]
]
--EXPECT--
Element:<div>Element:<div></div>Element:<div></div></div>
