JSFiddle - React, Tailwind, and code Playground

HTML

<input type="text" id="test"/>
<div></div>

JavaScript

$(document).ready(function(){
    
    var div = $("div");
    
    (function(){//anon function for scope
        
        var prevVal = $("#test").val();
        
        $('#test').on("input", function (e) {//'input will also handle paste event. i t will hadle every input'
            if(/*your `if` here*/ Math.random() > 0.3){
                div.text(true);
                this.value = prevVal;//You shall not pass!
            } else { div.text(false) }
            prevVal = this.value;
        });
        
    })();
    
});