JSFiddle - React, Tailwind, and code Playground

HTML

<script src="//searls.github.com/jasmine-all/jasmine-all-min.js"></script>
<script src="//ajax.googleapis.com/ajax/libs/angularjs/1.4.5/angular.min.js"></script>
<script src="//ajax.googleapis.com/ajax/libs/angularjs/1.4.5/angular-mocks.js"></script>

JavaScript

// Bootstrap app
angular
    .module('App', [])
	.config(configureApp)
	.service('Test', TestService);
	

// Do the testing
describe('Do the testing', () => {
    var Test;
    var $httpBackend;
    
	beforeEach(module('App'));
	beforeEach(inject((_Test_, _$httpBackend_) => {
        Test = _Test_;
        $httpBackend = _$httpBackend_;
        
        $httpBackend
            .whenGET('/firstCall.json')
        	.respond(200, { items: [1, 2, 3] });
        
        $httpBackend
            .whenGET('/secondCall/1.json')
        	.respond(200, { items: [4, 5, 6] });
    }));
    
    it('should work', () => {
        var result = null;
        
        Test
            .doubleHttpCall()
            .then(data => result = data);
        
        $httpBackend.flush();
        
        debugger;
        
        expect(result).toBe(4);
    })
});


//////////////////

function TestService($http)
{
    return {
        doubleHttpCall: doubleHttpCall
    }
    
    function doubleHttpCall()
    {
        return $http.get('/firstCall.json')
        	.then((response) => $http.get('/secondCall/' + response.data.items[0] + '.json'))
        	.then((response) => response.data.items[0]);
        
    }
}

TestService.$inject = ['$http'];

function configureApp($httpProvider)
{
    $httpProvider.useApplyAsync(true);
}

configureApp.$inject = ['$httpProvider'];