How To Write Selenium Test Cases? A Detailed Guide

Selenium is widely loved by web testers around the world thanks to its versatility and simplicity. Testing with Selenium is quite straightforward, which is why it is commonly used for people who want to go from manual to automation testing.

In this article, we will show you how to write Selenium test cases the right way.

Before You Write Your Selenium Test Case

Achieving 100% test coverage sounds amazing. However, that figure is almost impossible to reach, considering that most teams have resource and time constraints on their testing projects.

Testers should instead aim to test what their business requires. From here arises another challenge: the tres amigos (three friends) in software development don’t always share the same perspective. The tres amigos are:

• Product owner: Wants to solve a business problem.
• Developer: Builds a solution to solve the product owner's problem.
• Tester: Checks if the solution works and identifies potential issues.

Now we need to establish a common ground between them. Instead of going the traditional way where they discuss their plans in three different languages, the tres amigos use a shared language: Gherkin. It is structured by three primary statements: Given, When, and Then, with each statement describing a specific aspect of the system:

• The Given statement sets up the initial context for the behavior and defines the starting point of the system.
• The When statement describes the trigger that brings about a change or behavior in the system.
• The Then statement defines the expected outcome that should be observed after the event mentioned in the When statement.

What To Prepare To Write a Selenium Test Case

To effectively use Selenium, you should have a basic understanding of at least one programming language. Popular choices include Java, Python, C#, and Ruby. Familiarity with programming concepts such as variables, loops, conditionals, and functions is essential.

Additionally, ensure you understand the basics of web technologies:

• HTML
• CSS
• JavaScript
• Web elements (forms, buttons, links, etc.)

Prepare your integrated development environment (IDE). Popular IDEs for Selenium include:

• Eclipse
• IntelliJ IDEA
• VS Code

After that, install Selenium from its official website. Make sure to also install the WebDriver for the browser you want to test on. 

• ChromeDriver for Chrome
• GeckoDriver for Firefox
• Microsoft Edge WebDriver for Edge
   

Now you’re ready to write your Selenium test case.

Steps To Write a Selenium Test Case

Let’s start testing on the Facebook login page.
 

Your test case should look like this:
 

Let’s start testing!

First, import the necessary libraries. Here we need ChromeDriver to control Google Chrome. The ChromeOptions statement is needed to run in headless mode where you don’t need to load the GUI for better performance (learn more about headless browser testing here):

import org.openqa.selenium.By;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.WebElement;
import org.openqa.selenium.chrome.ChromeDriver;
import org.openqa.selenium.chrome.ChromeOptions;
import org.openqa.selenium.support.ui.ExpectedConditions; 
import org.openqa.selenium.support.ui.WebDriverWait;
import java.time.Duration;

Next, set up the path to the ChromeDriver executable in your machine:

public class FacebookLoginTest {
    public static void main(String[] args) {
        System.setProperty("webdriver.chrome.driver", "/path/to/chromedriver");

Now we can configure ChromeOptions to run in headless mode:

        ChromeOptions options = new ChromeOptions();
        options.addArguments("--headless"); // Run in headless mode (no GUI)

Then we initialize the WebDriver:

        WebDriver driver = new ChromeDriver(options);

And we use driver.get(url) to navigate to the URL you want. In our case, it is https://facebook.com:

        try {
            driver.get("https://www.facebook.com");

And we use driver.get(url) to navigate to the URL you want. In our case, it is https://facebook.com.

After that, right-click on the Facebook email field and choose Inspect. You should find the ID for it. Selenium will base on this ID to locate the field and fill in the information.

Similarly, you can do the same for the password field:

Now locate the elements and use sendKeys to add your email and password to it:

            // Locate email field example:
            WebElement emailField = new WebDriverWait(driver, Duration.ofSeconds(10))
                    .until(ExpectedConditions.visibilityOfElementLocated(By.id("email")));
            emailField.sendKeys("test@example.com");
        } finally {
            driver.quit();
        }
    }
}

Here’s our full code:

import org.openqa.selenium.By;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.WebElement;
import org.openqa.selenium.chrome.ChromeDriver;
import org.openqa.selenium.chrome.ChromeOptions;
import org.openqa.selenium.support.ui.ExpectedConditions; 
import org.openqa.selenium.support.ui.WebDriverWait;

import java.time.Duration;

public class FacebookLoginTest {
    public static void main(String[] args) {
        System.setProperty("webdriver.chrome.driver", "/path/to/chromedriver");

        ChromeOptions options = new ChromeOptions();
        options.addArguments("--headless"); // Run in headless mode (no GUI)

        WebDriver driver = new ChromeDriver(options);

        try {
            driver.get("https://www.facebook.com");
            // Locate email field example:
            WebElement emailField = new WebDriverWait(driver, Duration.ofSeconds(10))
                    .until(ExpectedConditions.visibilityOfElementLocated(By.id("email")));
            emailField.sendKeys("test@example.com");
        } finally {
            driver.quit();
        }
    }
}

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