How to expand an array in AngularJS?

Question

Angular

I found the extend method in the documentation, but it does not work as I want with arrays, an example is here jsfiddle.net/Lvc0u55v/11448
https://docs.angularjs.org/api/ng/function/angular...
Tried to do concat() , but probably not suitable for my task. I am doing a chat. The first time the chat page is loaded, I get the chat history as an array and save it to a local array in the service using $rootScope.apply() so that the data dynamically flies to the controller. The problem is that the data in the controller is not automatically updated when new messages are received. If you use angular.extend to expand the array, then the display problem is solved, but the problem arises that angular.extend simply overwrites one array with another, and does not connect as desired.
UPDI will give the code from my chat
Service, problematic place

function chatService($rootScope, flashService) {
        var host = location.origin.replace(/^http/, 'ws');
        var socket = new WebSocket(host);
        var initialization = {
            token: localStorage.getItem("satellizer_token"),
            getHistory: true,
            index: $rootScope.chatIndex //index defined first time on server
        }
        socket.onopen = function(obj) {
            socket.send(JSON.stringify(initialization));
        };
        var self = this;
        self.live = [];
        self.error = false;
        socket.onmessage = function(obj) {
            var response = JSON.parse(obj.data);
            if (!response.error) {
                $rootScope.chatIndex = response.index;
                angular.forEach(response.data, function(value, key) {
                    response.data[key].date = response.data[key].date.substring(11, 19);
                });
                // if single msg
                if (response.data.length == 1) {
                    $rootScope.$apply(function() {
                        self.live.push(response.data[0]);
                        // console.log('single message from server', response.data[0]);
                    });
                } 
                      //if get history from server
                   else {
                    $rootScope.$apply(function() {
                        //!!! ПРОБЛЕМА ЗДЕСЬ !!!
                        angular.extend(self.live, response.data); // в контроллере новое сообщение видно, но стрирается старое в self.lve, мне надо сохранить старое и дописать туда новое ,т.е. было ['1'], пришло с сервера ['2','3'], в контроллер отдали ['1', '2', '3']
                        // self.live = self.live.concat(response.data); // в self.live нормально сохраняется новое сообщение, но в контроллер оно не попадает 
                    });
                }
            } else {
                $rootScope.$apply(function() {
                    self.error = true;
                    flashService.error(response.errorMessage, false);
                });
            }
        }
        self.msgSend = function(msg) {
            if (socket.readyState == 1) {
                socket.send(JSON.stringify(msg));
            }
        }
        self.getHistory = function() {
            initialization.index = $rootScope.chatIndex;
            initialization.getHistory = true;
            socket.send(JSON.stringify(initialization));
        }
    }

Controller. If the service is concat , $scope.live is empty.
If the service extend(), $scope.live is not empty, but old messages are not saved

function chatController($scope, chatService, flashService, $rootScope, $location) {
        $scope.msgSend = function() {
            if (!$scope.isError()) {
                flashService.clearFlashMessage();
                obj.text = $scope.textMsg;
                obj.date = moment().format("YYYY-MM-DD HH:mm:ss");
                obj.token = localStorage.getItem("satellizer_token");
                chatService.msgSend(obj);
                $scope.textMsg = '';
            }
        };
        $scope.getHistory = function() {
            chatService.getHistory();
        }
      //!!! ПРОБЛЕМА ЗДЕСЬ !!!
        // new messages
        $scope.live = chatService.live;
    }

Answer 1

$scope.newArray = array1.concat(array2);
// можете добавить дополнительное слежение за изменением данных
$scope.$watch('newArray', function(newValue) {
  // делайте все, что хотите
  // хоть $scope.applyAsync();
});