JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://cdnjs.cloudflare.com/ajax/libs/handlebars.js/4.0.5/handlebars.js"></script>
<div id="output"></div>
<script type="template/handlebars" id="template">
	{{#each list}}
  	<b>unless:</b><br>
  	{{#unless ./condition}}
    	{{log 'this' .}} 
      {{log 'super' ..}}
      this="{{.}}" 
      parent="{{../value}}"<br>
    {{/unless}}
    <b>no unless:</b><br>
    this="{{.}}" 
    parent="{{../value}}"<br>
    <br>
  {{/each}}
</script>

JavaScript

var template = Handlebars.compile(document.getElementById('template').innerHTML);

document.getElementById('output').innerHTML = template({
	condition: false,
  value: 'parent value',
  list: [
    null,
  	'this is true',
  	'this is false',
  	'this is null'
  ]
});