javascript - how can i extend a service

Question

I am fairly new to angularjs and am not able to find any documentation or examples for this. What I am looking to do is to extend a basic service so that i can use the methods defined under the basic service from other services. So for example say i have a basic service as follows.

angular.module('myServices', []).

    factory('BasicService', function($http){
        var some_arg = 'abcd'
        var BasicService = {
            method_one: function(arg=some_arg){ /*code for method one*/},
            method_two: function(arg=some_arg){ /*code for method two*/},
            method_three: function(arg=some_arg){ /*code for method three*/},
        });
        return BasicService;
    }   
);

Now i want to define an Extended service that extends from the above BasicService so that i can use methods defined under the BasicService from my extended service. Maybe something like:

    factory('ExtendedService', function($http){
        var ExtendedService = BasicService();
        ExtendedService['method_four'] = function(){/* code for method four */}
        return ExtendedService;
    }

Answer 1

More cleaner and imperative way

.factory('ExtendedService', function($http, BasicService){

    var extended = angular.extend(BasicService, {})
    extended.method = function() {
        // ...
    }
    return extended;
}