JSFiddle - React, Tailwind, and code Playground
HTML
<div>one</div>
<div data-foo="foo">two</div>
<div data-bar="bar">three</div>
<div data-foobar="foobar">three</div>
JavaScript
Slick.definePseudo('data', function(value){
// wildcard data-startswith search
var outer = this.outerHTML || new XMLSerializer().serializeToString(this);
return outer.test('data-' + value);
});
console.log($$("div:data(foo)"));