Editorial Note: I originally wrote this post for the Test Huddle Blog. You can check out the original here, at their site.
This is the tenth article from the WebDriver Page Objects Series. Here I am going to share with you how to create a single place for handling the WebDriver initializations and creation of page objects. I call it App (short for application).
Two years ago while we were working on the first version of the BELLATRIX test automation framework, I did this research so that we can find the most convenient way for creating page objects.
Test Case
We will once again automate the main SearchEngine page. All of the code is placed inside the SearchEngineMainPage class.
Page Objects with Base Pages
All of our page objects need to derive from some of the base page classes which you can find after the page object’s code.
SearchEngineMainPage.Actions
public partial class SearchEngineMainPage : AssertedNavigatablePage
{
public SearchEngineMainPage(IWebDriver driver) : base(driver)
{
}
public override string Url => @"actualUrlToSite";
public void Search(string textToType)
{
SearchBox.Clear();
SearchBox.SendKeys(textToType);
GoButton.Click();
}
}Because of the base class, we can use in tests the GoTo and the Refresh methods. Also, we have access to the Assert property.
SearchEngineMainPage.Elements
public partial class SearchEngineMainPage
{
public IWebElement SearchBox => WrappedDriver.FindElement(By.Id("sb_form_q"));
public IWebElement GoButton => WrappedDriver.FindElement(By.Id("sb_form_go"));
public IWebElement ResultsCountDiv => WrappedDriver.FindElement(By.Id("b_tween"));
}We use the WrappedDriver protected property that comes from the base classes to locate the elements.
SearchEngineMainPage.Asserts
public partial class SearchEngineMainPage
{
public void AssertResultsCount(string expectedCount) => Assert.AreEqual(ResultsCountDiv.Text, expectedCount);
}We use the Assert protected property that comes from the base class to perform the validations. This property is test framework agnostic, which means that we can use it with MSTest or NUnit. The IAssert interface exposes methods that are not test framework agnostic. You can read more about the concrete implementation in my article- Create Hybrid Test Framework- Abstract Unit Test Framework
Page
This is the most basic base page object that we might have. It holds only a protected WebDriver property. We use this base page for pages that we do not need to navigate to them. E.g., middle pages in some wizard or something similar.
public abstract class Page
{
protected Page(IWebDriver driver) => WrappedDriver = driver;
protected IWebDriver WrappedDriver { get; }
}NavigatablePage
If we need to expose a navigate logic, you can use the below base class. It adds to the child page a GoTo and Refresh methods and obligates the page to set its URL.
public abstract class NavigatablePage : Page
{
protected NavigatablePage(IWebDriver driver) : base(driver)
{
}
public abstract string Url { get; }
public void GoTo() => WrappedDriver.Navigate().GoToUrl(Url);
public void Refresh() => WrappedDriver.Navigate().Refresh();
}App Design Pattern in Tests
public class SearchEngineTests
{
private App _app;
public void TestInitialize()
{
_app = new App();
}
public void TestCleanup()
{
_app.Dispose();
}
public void UseApp_SearchTextInSearchEngine_UseElementsDirectly()
{
var searchEngineMainPage = _app.GoTo<SearchEngineMainPage>();
searchEngineMainPage.Search("Automate The Planet");
searchEngineMainPage.AssertResultsCount("236,000 RESULTS");
}
}As you can see, we do not have any WebDriver initialization code in the tests. Everything is happening behind the scenes the App class. Moreover, the App instance is responsible for the initialization and navigation to the different page objects. Here, we use the generic GoTo method to navigate to the SearchEngineMainPage.
App
public class App : IDisposable
{
private IWebDriver _driver;
public App(BrowserType browserType = BrowserType.Firefox)
{
StartBrowser(browserType);
}
public void Dispose() => _driver.Dispose();
public TPage Create<TPage>()
where TPage : Page
{
var constructor = typeof(TPage).GetTypeInfo().GetConstructors(BindingFlags.NonPublic | Bind - ingFlags.Instance).FirstOrDefault();
var page = constructor.Invoke(new object[] { _driver }) as TPage;
return page;
}
public TPage GoTo<TPage>()
where TPage : NavigatablePage
{
var constructor = typeof(TPage).GetTypeInfo().GetConstructors(BindingFlags.NonPublic | Bind - ingFlags.Instance).FirstOrDefault();
var page = constructor.Invoke(new object[] { _driver }) as TPage;
page.GoTo();
return page;
}
private void StartBrowser(BrowserType browserType = BrowserType.Firefox)
{
switch (browserType)
{
case BrowserType.Firefox:
_driver = new FirefoxDriver();
break;
case BrowserType.InternetExplorer:
break;
case BrowserType.Chrome:
break;
default:
throw new ArgumentException("You need to set a valid browser type.");
}
}
}In the constructor of the class, we start the browser. We have two generic methods for creation of the page objects. We use reflection to initialize the objects. However, there are various ways to do the same thing even better. I prefer to use inversion of control containers or service locators. You can read more about the IoC containers in my article- Use IoC Container to Create Page Object Pattern on Steroids
For more detailed overview and usage of many more design patterns and best practices in automated testing, check my book “Design Patterns for High-Quality Automated Tests, C# Edition, High-Quality Tests Attributes, and Best Practices”. You can read part of three of the chapters:
Defining High-Quality Test Attributes for Automated Tests
Benchmarking for Assessing Automated Test Components Performance
