HTL data-sly-test

[#1]

Is there a way to test if listChildren will return anything? Something along the line of: <sly data-sly-test=${item.listChildren.size > 0} />

[#2]

Good question - here is more explanation on test -- htl-spec/SPECIFICATION.md at master · adobe/htl-spec · GitHub

See Section -- 2.2.5. Test

[#3]

you can use resource.hasChildren

HTL Global Objects

Resource (Apache Sling 8 API)

[#4]

You can call any method that has no arguments in data-sly-test.

In your case check if your item has these methods.

[#5]

Thank you all! Your answers pointed me to a solution. I was able to test whether or not the item had children this way:

<sly data-sly-test=${item.listChildren.hasNext} />