JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.1.1/jquery.min.js"></script>
	<div ng-app='demo'>
	<div ng-controller='loadData' ng-init="showMessage = true">
  <form name="form" novalidate autocomplete="off" role="form">
<textarea name="firstname" id="firstname" ng-model="name" maxlength="60" minlength="50" ng-trim="false"></textarea> 
<div ng-messages="form.firstname.$error" role="alert"><span ng-message="required">Please enter Name</span></br><span ng-message="minlength" ng-show="showMessage">min-Length:{{ 50 - name.length}}</span>
    </div>
    </div>

JavaScript

var demo = angular.module('demo', []);
demo.controller('loadData', function($scope){
      $scope.showMessage=true;
      $('#firstname').on("keyup", function(e) {
        if (this.value.length >= 50) {
        $scope.showMessage=false;
        }
        else{
        $scope.showMessage=true;
        }
      });
});