Page Object Model

Page Objects are a way to encapsulate the technical details of a web page and the services it provides so that the developer of a test does not need to delve into the structure of the webpage. Essentially the Page Object acts as an interface between the web page and the testing of that page. The Page Object defines all the elements and actions provided by the web page and the test case uses these to execute the test(s). By clearly delineating the test code from the page objects, you will be able to use the same page objects in a variety of tests cases and achieve code re-use. Another major positive to this approach is that if the application being tested changes then only the Page Object definition needs to be changed in one place and all of the existing test should still work once that change had been made.

I will provide tangible examples later but I used C# to define the Page Object and its properties and methods. The test cases use these objects and methods with NUnit to provide Assertions. This is an important point; the tests, and not the Page Object, should be responsible for making assertions about the state of a page. The Page Object defines the properties and methods you need for creating a test and the test itself uses those properties and methods to make Assertions, allowing us to determine if a test has passed or failed.

The Code

I think the best way to learn a new concept is by getting your hands dirty and trying it out. In this example I will show how to use the Page Object Model to define a Login Page.
Below I will create a page object for Login and I will define some properties (username, password and login button) and a method to login. As the LoginUser() method will take us to a new page, it will return a HomePage object.

using OpenQA.Selenium;
using OpenQA.Selenium.Support.PageObjects;
using NUnit.Framework;

namespace PageObjectModel
{
  public class LoginPage
  {
      private IWebDriver driver;
   
      [FindsBy(How = How.Id, Using = "tbxUsername")]
      private IWebElement tbxUsername;

      [FindsBy(How = How.Id, Using = "tbxPassword")]
      private IWebElement tbxPassword;

      [FindsBy(How = How.Id, Using = "btnLogin")]
      private IWebElement btnLogin;

      public LoginPage(IWebDriver driver)
      {
        this.driver = driver;
        PageFactory.InitElements(driver, this);
      }

      public HomePage UserLogin(string user, string pass)
      {
        tbxUsername.SendKeys(user);
        tbxPassword.SendKeys(pass);
        btnLogin.Click();

        return new HomePage(driver);
      }
  }
}

So that’s a very simple Page Object setup, I’ll go through it in more details once we have the code for the test case that uses it:

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