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 Test}}{{.}}, {{/each}}</script>

JavaScript

function MyCompiler() {
  Handlebars.JavaScriptCompiler.apply(this, arguments);
}
MyCompiler.prototype = new Handlebars.JavaScriptCompiler();

MyCompiler.prototype.nameLookup = function(parent, name, type) {
	if (type === 'context') {
  		return this.source.functionCall('helpers.lookupLowerCase', '', [parent, JSON.stringify(name)])
	} else {
			return Handlebars.JavaScriptCompiler.prototype.nameLookup.call(this, parent, name, type);
 }
}

var env = Handlebars.create();
env.registerHelper('lookupLowerCase', function(parent, name) {
	return parent[name.toLowerCase()]
})

env.JavaScriptCompiler = MyCompiler;

var template = env.compile(document.getElementById('template').innerHTML);
document.getElementById('output').innerHTML = template({
	test: [ "a","b","c"]
});