Test for empty variable in Swig template

Question

In Twig I have operator is and test for empty variable (string or array):

{% if info is empty %}
    ...
{% endif %}

How I can do something like this in Swig template?

Answer 1

Simply do

{% if !info.length %}
...
{% endif %}

This will match strings (""), arrays ([]) and any other object which doesn't have a .length property with truthy value.

Answer 2

{% if Object.keys(info).length != 0 %}

for an object/dict empty test