Exploring Selenium 4 Alpha: DevTools, Window Management, Relative Locators & Full‑Page Screenshots

ChromiumDriver and DevTools

Selenium 4 introduces a unified ChromiumDriver class that gives direct access to browser DevTools, replacing the previous separate EdgeDriver and ChromeDriver implementations. The following Java snippet creates a driver, opens a session, and runs a JavaScript console log through DevTools.

// create driver
WebDriver driver = new ChromeDriver();
Connection connection = null;
DevTools devtools = new DevTools(connection);
devtools.createSession();
String message = "chrome 浏览器测试Demo!";
driver.get("https://www.bing.cn");
JavascriptExecutor js = (JavascriptExecutor) driver;
js.executeScript("console.log('" + message + " ' ) ;");

The code demonstrates how DevTools can be used for tasks such as performance evaluation and page‑load timing.

Better Window and Tab Management

Selenium 4 adds the ability to open and control multiple windows or tabs without relying on a separate driver instance. This is especially useful when tests need to interact with different pages simultaneously.

WebDriver window2 = driver.switchTo().newWindow(WindowType.TAB);
window2.get("url");
WebDriver window1 = driver.switchTo().newWindow(WindowType.WINDOW);
window1.get("url");

The newWindow() method creates a new window or tab based on the WindowType argument.

Relative Locators

Selenium 4 Alpha enriches element location by allowing selectors relative to other elements. Available methods include: toLeftOf() – element positioned to the left of a reference element. toRightOf() – element positioned to the right of a reference element. above() – element located above a reference element. below() – element located below a reference element. near() – element within a configurable pixel distance (default 50 px) of a reference element.

Full‑Page Screenshot

Firefox now supports a dedicated method for capturing the entire page without casting to TakesScreenshot. The driver must be cast to FirefoxDriver to access this functionality.

File src = ((FirefoxDriver) driver).getFullPageScreenshotAs(OutputType.FILE);

These enhancements illustrate Selenium 4's focus on more powerful, flexible browser automation, encouraging developers to explore further capabilities.