Author: Maria Reyes Freaner

Testing an ESB with Selenium!

Manual integration testing is the first “test plan” in application development. This strategy quickly becomes a pain, so introducing automation early is important with any project. When working on an enterprise service bus, automated testing is a must have. Early in the development of Orbital Bus we began implementing automated unit tests and even automated integration tests in our continuous integration pipeline. Scripting such tests is a common approach for similar ESB projects. Why are we writing an article about Selenium then? Eventually we decided that console applications weren’t enough. It’s very common to have web applications that call to multiple micro-services via an ESB, so we wanted to build one and test it out. How would we automate those tests? We chose Selenium.


Selenium is an open-source testing solution for web apps. Selenium helps you automate tasks to make sure your web application is working as you expect. Selenium has multiple tools:

  • Selenium 2 (WebDriver): Supplies a well-designed object-oriented API that provides improved support for modern, advanced web-app testing problems.
  • Selenium 1 (Remote Control): Provides some features that may not be available in Selenium 2 for a while, including support for almost every browser and support of several additional languages (i.e. Java, Javascript, Ruby, PHP, Python, Perl, and C#).
  • Selenium IDE: Helps with rapid prototyping of tests with Selenium for experienced developers or beginner programmers who are looking to learn test automation.
  • Selenium-Grid: Allows for tests to run on different machines and in different browsers in parallel.

For Orbital Bus, we used Selenium 2 since it supports nine different drivers (including mobile OS’s). That ensures going forward we can adapt our tests however we need.

We know Orbital Bus will be an essential component in a web application, so we needed to test the ability of Orbital Bus to handle a lot of requests from a browser-based application. By stressing Orbital Bus with a lot of requests, we could verify that our message broker receives and delivers the messages properly and the Dispatcher and Receiver handles and translates the messages as expected.

In addition to Selenium 2, we needed to use a web driver to conduct the testing. We chose the Phantomjs Driver. This driver is “headless”, meaning we were able to manipulate all the elements in the page. Keeping in mind we wanted to stress test the system, we weren’t concerned with complicated UI scenarios. We were using Selenium just to fire requests and make sure that a UI element changed showing receipt of the response. Other test harnesses for browsers often open extra pages to capture the screen. That kind of interaction was beyond our scope. We wanted to just focus on messages getting through. The following code section is an example of our tests.

public void RequestsForYahooWeather()

var countryJsonPath = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "Configs", "countries.json");
var jsonString = File.ReadAllText(countryJsonPath);
List countries = JsonConvert.DeserializeObject<List>(jsonString);

foreach (country countryO in countries)
var driver = new PhantomJSDriver();
WebDriverWait wait = new WebDriverWait(driver, TimeSpan.FromSeconds(10));
IWebElement wElement = driver.FindElement(By.Id("CityName"));
IWebElement wElementTemperature = driver.FindElement(By.Id("Temperature"));
IWebElement wElementButton = driver.FindElement(By.Id("getWeatherInfo"));
Assert.NotStrictEqual("-", wait.Until(drv => drv.FindElement(By.Id("Temperature")).GetAttribute("value")));



Our experience with Selenium was easy to implement and quick in performing the necessary tests. Our tests successfully passed, demonstrating that Orbital Bus can work with web applications and have no negative impact over console apps. Selenium not only let us confirm Orbital Bus was working as intended with a web application, but it will afford us with the flexibility and performance needed to grow these tests in the future as we expand our use cases.


  • Maria
  • Reyes Freaner