angular.module('myapp').
factory('messageservice', ['$http', '$q', function ($http, $q) {

function foo(query) {
    return 'foo';
}

function getServerMessages(query) {
    var query=foo();
    return $http.get(query))
                    .then(function (result) {
                        console.log('success');
                    }, function (err) {
                        debugger;
                        console.log('error');
                    });
}

return {
    getMessages: getFolderMessages,
    getMessageDetails: getServerMessages
};
}]);

spyOn($http, 'get').andReturn(aPromiseYouShouldResolveAtSomePointInYourTest);
expect($http.get).toHaveBeenCalled();
var queryItWasCalledWith = $http.get.mostRecentCall.args;
// do some assertions on queryItWasCalledWith