Page Object Model

Learning objectives#

• Create page object classes
• Keep locators private
• Return the next page from actions
• Write readable tests on top

Explanation#

Each page or reusable component gets a class exposing user actions (LoginAs, SearchFor) and read-only state (ErrorMessage).

Locators stay private inside the class; if the UI changes, you fix one place.

Actions that navigate return the next page object, giving fluent, readable tests.

Keep assertions in tests, not page objects, so pages stay reusable.

Code example: Login page object and test#

1public class LoginPage(IWebDriver driver)
2{
3    private readonly By email = By.Id("email");
4    private readonly By password = By.Id("password");
5    private readonly By submit = By.CssSelector("[data-testid='login-submit']");
6    private readonly By error = By.CssSelector("[role='alert']");
7

8    public LoginPage Open() { driver.Navigate().GoToUrl(Config.BaseUrl + "/login"); return this; }
9

10    public DashboardPage LoginAs(string user, string pass)
11    {
12        driver.FindElement(email).SendKeys(user);
13        driver.FindElement(password).SendKeys(pass);
14        driver.FindElement(submit).Click();
15        return new DashboardPage(driver);
16    }
17

18    public string ErrorMessage => driver.FindElement(error).Text;
19}
20

21[Test]
22public void Valid_user_sees_their_name()
23{
24    var dashboard = new LoginPage(driver).Open().LoginAs("asha@example.com", "Passw0rd!");
25    Assert.That(dashboard.Greeting, Is.EqualTo("Namaste, Asha"));
26}

The test reads like a user story; a changed login button selector is fixed in LoginPage only.

This example is illustrative. Copy or download it and run it in your own environment; the expected output is shown above.

Step-by-step explanation#

1. Locators are private fields.
2. Open and LoginAs describe user actions.
3. LoginAs returns the DashboardPage.
4. The test asserts on the result.

Real-world use case#

Common mistakes#

Best practices#

• One class per page/component
• Private locators
• Return next page objects
• Assertions in tests only

Remember this#

Practice exercise#

1public ResultsPage SearchFor(string term)
2{
3    driver.FindElement(By.Name("q")).SendKeys(term + Keys.Enter);
4    return new ResultsPage(driver);
5}

Mini quiz#

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Related topics#

My notes#

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