Selenium Headless Browser Testing: HTMLUnitDriver & PhantomJS

What is a Headless Browser?

A headless browser is a web browser that operates without a graphical user interface (GUI). These browsers work in the background, executing commands and interacting with web pages without displaying any visible interface. This allows developers to perform various operations, such as testing and automation, without the need for a visually interactive browser session.

# Types of Headless Drivers

– HtmlUnit
– PhantomJS
– Ghost
– ZombieJS

PhantomJS

PhantomJS is a headless browser that employs the WebKit rendering engine and supports various web standards including HTML5, CSS3, and JavaScript. It is commonly used for tasks such as screen capture and page automation. PhantomJS is open-source and compatible with multiple operating systems.

# Features of PhantomJS

– Headless Testing
– Screen Capture Capability
– Network Monitoring
– Unit Testing on the Command Line
– PDF Generation from HTML

PhantomJS integrates well with Selenium and makes it easy to write automation code. It also supports various tasks such as taking screenshots and monitoring network activity.

# Steps to Run Selenium with PhantomJS

1. Install Eclipse with Selenium
2. Download and Extract PhantomJS
3. Download and Add PhantomJS Driver to Your Project
4. Write and Run the Selenium Code

“`java
from selenium import webdriver
from selenium.webdriver.common.desired_capabilities import DesiredCapabilities

# Set up PhantomJS options
phantomjs_options = webdriver.DesiredCapabilities.PHANTOMJS.copy()
phantomjs_options[‘phantomjs.page.settings.userAgent’] = ‘Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.3’

# Set up the PhantomJS driver
driver = webdriver.PhantomJS(‘/path/to/phantomjs’, desired_capabilities=phantomjs_options)

# Perform actions using the driver
driver.get(‘https://www.example.com’)
print(driver.title)

# Close the driver
driver.quit()
“`

HTMLUnitDriver

HTMLUnitDriver is a lightweight and fast implementation of a web driver that offers several advantages:

# Features of HTMLUnitDriver

– Speed and Performance Improvements
– Allows for Browserless Setup
– Support for HTTPS and HTTP Protocols
– Multitasking
– Cookies Support
– Excellent JavaScript Support

# Steps to Use HTMLUnit Driver with Selenium

1. Copy and Run the Standard Selenium Code
2. No Additional Jar Files Needed

“`java
package htmldriver;

import org.openqa.selenium.By;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.WebElement;
import org.openqa.selenium.htmlunit.HtmlUnitDriver;

public class htmlUnitYest {
public static void main(String[] args) {
// Creating a new instance of the HTML unit driver
WebDriver driver = new HtmlUnitDriver();

// Navigate to Google
driver.get(“http://www.google.com”);

// Locate the search box using its name
WebElement element = driver.findElement(By.name(“q”));

// Enter a search query
element.sendKeys(“Guru99”);

// Submit the query
element.submit();

// This code will print the page title
System.out.println(“Page title is: ” + driver.getTitle());

driver.quit();
}
}
“`

Benefits of Headless Browser Testing

Headless browser testing provides several benefits:

– Efficient and Effective Testing
– Time and Resource Savings
– Improved Performance

# Limitations of Headless Browser Testing

– Debugging Can Be Challenging
– May Miss Cosmetic Bugs
– Does Not Mimic Exact User Behavior

By integrating headless browser drivers like HTMLUnitDriver and PhantomJS with Selenium, developers can automate and test web applications efficiently and effectively, saving both time and resources.