JSFiddle - React, Tailwind, and code Playground

HTML

<div ng-app="PatternApp">
<div ng-controller="PtrnCtrl">
<form name="ptrfrm">
<input type="text" ng-model="model" id="input" name="input" ng-pattern="ptrn" /><br>
Result==> {{ptrfrm.input.$valid}}
</form>
</div>
</div>

JavaScript

var app = angular.module('PatternApp',[]);
app.controller('PtrnCtrl', function($scope){
	$scope.ptrn = "amazon";
});