JSFiddle - React, Tailwind, and code Playground

HTML

<div ng-app="myApp" ng-controller="myCtrl">
    
    <button ng-click=update()>Update</button>
    
</div>

JavaScript

var app = angular.module('myApp', []);

app.controller('myCtrl', function ($scope,$window) {
    console.log("in controller ",window.test);
    
    $scope.update = function () {
        $window.test="new";
    };
    
    $scope.$watch(function () {
        return $window.test 
    }, function(n,o){
        console.log("changed ",n);
    });

})