Are you curious about automating tests for websites or web applications? Have you come across the idea of using a browser without a visible interface in combination with Selenium?
In this article, we will discuss the concept of headless browser testing with Selenium, its benefits, and how you can start using Selenium to conduct efficient and reliable tests without having a browser window appear on your screen.
Selenium
Selenium is a helpful tool that allows developers to test web browsers without looking at them on the screen. It enables them to run automated tests fast and efficiently without requiring a visual interface. It not only conserves time but also saves valuable resources.
Selenium is helpful when finding problems that might be difficult to notice in a normal testing setup with a user interface. The lack of performance or improper organization of the webpage causes these problems.
It is important to remember that headless testing has its limitations. Accordingly, it is advisable to incorporate it with traditional methods. These traditional methods involve seeing the browser interface to ensure thorough testing.
What Headless Browsers Testing Means?
Developers and testers can manipulate them using code. This benefits developers and testers because they can automatically use headless browsers to test websites. Headless browsers can mimic human actions, such as clicking buttons or completing forms, just as a person would.
Headless browsers have a great advantage: they can run tests independently without human assistance. It means they can complete tasks more quickly and efficiently. In the past, older versions of Selenium depended on the HTMLUnitDriver.
HTMLUnitDriver is a fast and lightweight way to simulate a web browser without a visible window. It is designed explicitly for WebDriver and is a headless browser, meaning it operates without a graphical user interface (GUI). With quick performance and clarity, HTMLUnit Driver is a popular choice for automating web testing tasks.
Headless Browser Testing with Selenium
Headless automation in Selenium refers to the execution of Selenium tests without a visible browser window. Instead of launching a browser window to interact with web elements, headless automation runs tests in the background, making it faster and more efficient.
Using headless browsers like Chrome Headless or Firefox Headless, Selenium can perform web scraping, automated testing, and data extraction without needing a graphical user interface (GUI). Selenium Webdriver is particularly helpful when dealing with dynamic web pages.
Executing Headless Browser Tests Using The HTMLUnitDriver in Selenium.
HtmlUnitDriver is a Selenium WebDriver framework tool that allows you to test web applications automatically. It's designed for testing websites without even opening a visible browser. It uses a Java library called HtmlUnit, which imitates a browser's behavior.
Here's a simple step to run Selenium tests with a headless browser using the HTMLUnitDriver.
Step 1: Download the Necessary Files.
To begin, go to the website and download the files you need for HtmlUnitDriver. Ensure you get the latest version and save it on your computer. After that, open your project in Eclipse and add the downloaded file to your project's build path. To do this, right-click on your project, go to Build Path, then Configure Build Path. In the Libraries section, click Add External JARs, choose the file you downloaded from its folder, and click Apply and Close to complete the process.
Step 2: Check the Downloaded File
After including the file, you can effortlessly import the required class to your test by executing the following command.
We can create new instances using the following command.
WebDriver driver = new HTMLUnitDriver();
Step 4: Write The Test Code Using HTMLUnitDriver.
You can write a test code using the created HTMLUnitDriver instance.
Example
An example shows running selenium test cases in headless mode with HTMLUnitDriver.
Code
public class App {
public static void main(String[] args) {
// Create an instance of HtmlUnitDriver
WebDriver driver = new HtmlUnitDriver();
// Open url
driver.get("https://www.google.com/");
// Print a message
System.out.println("Welcome to Coding Ninjas..\n");
// Print a message showing that HtmlUnitDriver is working
System.out.println("Executing HtmlUnitDriver in Headless mode..\n");
// Print the contents you want to print
System.out.println(">> Page Title : " + driver.getTitle());
System.out.println(">> Page URL : " + driver.getCurrentUrl());
}
}
Output
Explanation
The code above is a Java program demonstrating how to use HtmlUnitDriver to test a web browser without a visible interface. To begin, we create an HtmlUnitDriver object. This object allows us to interact with the browser. Afterward, it retrieves and prints the title and URL of the page. The HtmlUnitDriver enables automated testing without needing a physical browser window. This code example shows the fundamental steps for setting up and utilizing HtmlUnitDriver for headless browser testing in Selenium.
Executing Headless Browser Tests Using The Headless Chrome Browser
Headless browser testing allows you to run automated website tests without opening a visible web browser. Headless Chrome is a version of the Google Chrome browser that works without a graphical interface. Using frameworks like Selenium, you can write scripts that affect website user interactions and show the expected results.
Step 1: Download the Latest Version of the Chrome Driver.
You need to install the latest version of chromeDrive into your system.
Step 2: Add the File to Eclipse
After extracting the file, you must add these files to the Eclipse. To do this, click "Build to Configure" and "Add External JARs." After adding the file it will been seen like this in Eclipse.
Step 3: Create Instance
When using ChromeOptions, you can run tests in headless mode by including the argument "headless" or "--headless" in the syntax. Another way is to use the setHeadless() method and pass true as an argument. Both methods allow you to perform browser automation without a visible browser window.
Step 4: Write the Test Code using ChromeDriver.
You can write a test code using the created ChromeDriver instance.
Example
An example shows running selenium test cases in headless mode with ChromeDriver.
Code
public class Chrome_Browser_in_Headless_mode {
public static void main(String[] args) {
// Set the path of the ChromeDriver executable
System.setProperty("webdriver.chrome.driver","C://demo/src/main/java/com/demo/demo/chromedriver.exe");
// Create ChromeOptions instance
ChromeOptions options = new ChromeOptions();
// Add the "--headless" argument to run in headless mode
options.addArguments("--headless");
// Create a new ChromeDriver instance
WebDriver driver = new ChromeDriver(options);
// Open the url
driver.get("https://www.google.com/");
// Print some messages
System.out.println("Welcome to Coding Ninjas!!..\n");
System.out.println("Hi Ninjas!!..\n");
System.out.println("Launching Chrome Browser in Headless mode..\n");
// Print the page title and URL
System.out.println(">> Page Title: " + driver.getTitle());
System.out.println(">> Page URL: " + driver.getCurrentUrl());
//Quitting the browser
driver.quit();
}
}
Output
Explanation
This code shows how to use Headless Chrome for browser automation. The code selects the path for the ChromeDriver executable, forms a ChromeOptions object, adds the "--headless" argument, and initializes the WebDriver with these choices. It then opens a defined URL, prints some messages, retrieves and prints the page title and URL, and ultimately closes the browser. This code shows some basic steps to control Chrome in headless mode using Selenium WebDriver.
Executing Headless Browser Tests Using The Headless Firefox Browser
In addition to Headless Chrome, Headless Firefox is another option for executing these tests. Headless Firefox is a version of Mozilla Firefox that operates without a graphical interface, allowing programmable and automated browser tasks. Using testing frameworks like Selenium, you can write scripts to interact with Headless Firefox, perform navigation, interact with web elements, and show results.
Example
An example shows running selenium test cases in headless mode with Firefox browser. Code
public class Chrome_Browser_in_Headless_mode {
public static void main(String[] args) {
// TODO Auto-generated method stub
// Set the path of the GeckoDriver executable
System.setProperty("webdriver.gecko.driver","/demo/src/main/java/com/demo/demo/geckodriver.exe");
// Create FirefoxOptions instance
FirefoxOptions options = new FirefoxOptions();
// Set headless mode to true
options.setHeadless(true);
// Create a new FirefoxDriver instance
WebDriver driver = new FirefoxDriver(options);
// Open the url
driver.get("https://www.google.com/");
// Print messages
System.out.println("Welcome to Coding Ninjas...Let's learn something new\n");
System.out.println("Launching Firefox in Headless mode...\n");
// Print the page title and URL
System.out.println(">> Page Title: " + driver.getTitle());
System.out.println(">> Page URL: " + driver.getCurrentUrl());
}
}
Output
Explanation
This code shows how to use Headless Firefox for browser automation. It specifies the path for the GeckoDriver executable and forms a new instance of FirefoxOptions to configure the Firefox browser. The code allows the browser to run headless mode and creates a new FirefoxDriver. It opens the Google homepage, prints a welcome message, and shows the page title and URL. This code allows you to run Firefox in headless mode and recover information from web pages.
Applications of Selenium Headless
There are many applications of Selenium headless like:
Selenium headless browser testing offers data scraping, aggregation, and pricing monitoring by automating data extraction from websites.
Headless browser testing makes it possible to automate online application testing and ensure all performance, user interactions, and visual components are in good working order.
Headless browser testing can proactively inform users of website updates, mistakes, or performance concerns, enabling speedy resolution of any problems.
Search engine optimization (SEO) characteristics, including meta descriptions, headers, and text architecture, may be analyzed and evaluated for web pages using headless browser testing with Selenium by emulating a browser environment.
With headless browser testing, web developers may test web applications across various browsers and versions, assuring consistent operation and presentation across many platforms.
Advantages
There are many advantages of Headless Browser testing:
Selenium's headless browser testing feature enables thorough coverage of various user environments by testing web applications in multiple browsers and versions.
Compared to conventional browser-based testing, headless browsers accelerate test execution times by doing away with the necessity for GUI rendering.
Selenium's headless browser testing makes it simple to scale up by running tests concurrently, making it possible to effectively test large and complicated online applications.
Testing with a headless browser can drastically save infrastructure expenses because it does not require actual computers or virtual desktop equipment.
Automated and effective testing is made possible by smoothly integrating headless browser testing with CI/CD pipelines as part of the software development lifecycle.
Disadvantages
There are some disadvantages of Headless Browser testing:
Some JavaScript frameworks and libraries may only partially be supported by headless browsers, leading to incompatibilities and insufficient test coverage.
Debugging and troubleshooting can be more difficult without a visible interface, making it more difficult to pinpoint the main reason for test failures.
When using different versions of browsers, distinct headless browser implementations may have their own restrictions and compatibility issues that call for updates and modifications.
Since headless browsers don't have a graphical user interface, it can be more challenging and inaccurate to simulate intricate user interactions like mouse movements and visual validations.
Headless browsers need more computational power, which lengthens execution times and could reduce the effectiveness of the test suite as a whole.
A headless browser is a web browser that doesn't need a GUI to navigate the internet. It operates in the background, so browsing and automated testing may be done without a visible browser window.
Which programming languages support headless browser testing with Selenium?
Selenium supports multiple programming languages, including Java, Python, C#, Ruby, and JavaScript. Therefore, depending on your preferences and project requirements, you can test a headless browser using Selenium with any of these languages.
What are the advantages of using headless browser testing with Selenium?
Some advantages of headless browser testing with Selenium include faster test execution, improved scalability, and the ability to run tests in headless environments, such as continuous integration and deployment pipelines. It also allows for running tests on servers without a desktop environment.
Does headless browser testing allow us to take screenshots and generate reports?
Headless browser testing allows capturing screenshots and generating reports for analysis and documentation.
Can multiple instances of headless browsers be run simultaneously to speed up test execution?
Multiple headless browser instances can be executed in parallel, allowing for concurrent testing and faster test execution in a distributed or parallel test environment.
Conclusion
In this article, we will learn about headless browser testing with Selenium. In this article, we have discussed Selenium and what headless browser testing means. We have also explored headless browser testing in HTMLUnitDriver, Chrome, and Firefox. We also have learned about different applications of headless browsers in this article. Ultimately, we discuss the advantages and disadvantages of headless browsers that developers should consider while using.
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