JSFiddle - React, Tailwind, and code Playground

HTML

<div ng-app="app" ng-controller="app">
  <textarea size-watch>{{ height }}</textarea>
</div>

JavaScript

angular.module("app", [])
.controller("app", function() {
})
.directive("sizeWatch", function() {
	return {
  	restrict: "A",
    link: function(scope, elem) {
			scope.$watch(function() { return elem[0].offsetHeight; }, function(newHeight, oldHeight) {
        scope.height = newHeight;
      }, true);
    }
  }
});