Selenium WebDriver Setup

Learning objectives#

• Install Selenium for .NET
• Write and run a first test
• Run headless for CI
• Clean up the browser after each test

Explanation#

Packages: Selenium.WebDriver plus a test framework (NUnit here). Selenium Manager downloads the matching browser driver automatically.

Create a driver (new ChromeDriver(options)), navigate, find elements, act and assert.

Headless mode runs without a visible window — required on most CI servers.

Always Quit() the driver in teardown, or browsers pile up and memory runs out.

Code example: First Selenium test#

1// dotnet new nunit -n Shop.UiTests && cd Shop.UiTests
2// dotnet add package Selenium.WebDriver
3using NUnit.Framework;
4using OpenQA.Selenium;
5using OpenQA.Selenium.Chrome;
6

7public class LoginTests
8{
9    private IWebDriver driver = null!;
10

11    [SetUp]
12    public void Start()
13    {
14        var options = new ChromeOptions();
15        options.AddArgument("--headless=new");
16        options.AddArgument("--window-size=1366,900");
17        driver = new ChromeDriver(options);
18    }
19

20    [Test]
21    public void Valid_login_shows_dashboard()
22    {
23        driver.Navigate().GoToUrl("https://staging.shop.example/login");
24        driver.FindElement(By.Id("email")).SendKeys("asha@example.com");
25        driver.FindElement(By.Id("password")).SendKeys("Passw0rd!");
26        driver.FindElement(By.CssSelector("button[type=submit]")).Click();
27

28        Assert.That(driver.Url, Does.Contain("/dashboard"));
29    }
30

31    [TearDown]
32    public void Stop() => driver.Quit();
33}

Passed!  - Failed: 0, Passed: 1, Skipped: 0, Total: 1, Duration: 3 s

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. SetUp creates a headless Chrome before each test.
2. The test navigates, types and clicks.
3. The assertion checks the redirect.
4. TearDown always quits the browser.

Real-world use case#

Common mistakes#

Best practices#

• Headless in CI
• Quit in teardown
• Config for URLs and users
• Explicit waits (next lessons)

Remember this#

Practice exercise#

1var options = new FirefoxOptions();
2options.AddArgument("-headless");
3driver = new FirefoxDriver(options);

Mini quiz#

Want more? Practise all Automation Testing MCQs · Automation Testing interview questions

Related topics#

My notes#

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