How to Use JavaScriptExecutor in Selenium

Faisal Khatri

Posted On: September 17, 2024

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Read time11 Min Read

Selenium is an open-source suite of tools and libraries that allows you to interact with browsers to perform various operations like sending text, clicking on a button, selecting drop-downs, etc. However, there are scenarios where the actual Selenium WebDriver commands do not work as expected. This is where JavaScriptExecutor comes into the picture.

In this blog, we discuss JavaScriptExecutor in Selenium and how to get started with practical use cases and examples.

This article is a part of our Content Hub. For more in-depth resources, check out our content hub on Selenium JavaScript Tutorial.

TABLE OF CONTENTS

What Is JavaScriptExecutor in Selenium?

JavaScriptExecutor is an interface provided by Selenium that helps in executing JavaScript commands. This interface provides methods to run JavaScript on the selected window or the current web page. It is available for all the language bindings supported by Selenium.

The JavaScriptExecutor in Selenium can be used directly by importing the following package in the automation test scripts:

JavaScriptExecutor in Selenium provides two methods to interact with the WebElements:

  • executeScript(): This method executes JavaScript in the context of the currently selected window or frame in Selenium. The script will be executed as the body of an anonymous function.
  • executeAsyncScript(): This method executes an asynchronous snippet of JavaScript in the context of the currently selected window or frame in Selenium. The script will be executed as the body of an anonymous function.

Note: The major difference between executeScript() and executeAsyncScript() methods is that the script invoked using the executeAsyncScript() has to signal about the completion of execution using the callback() function.

Invoking methods using executeAsyncScript() are majorly used when sleep has to be performed in the browser under test or when tests have to be synchronized within an AJAX application.

Why Use JavaScriptExecutor in Selenium?

There are scenarios where some WebDriver commands do not work as expected due to multiple reasons. In these cases, we take the help of JavaScriptExecutor.

For example, traditionally, to locate a WebElement, we use different Selenium locators such as ID, Name, CSS Selector, XPath, etc. If these locators do not work, or you are handling a tricky XPath, in such cases, JavaScriptExecutor helps to perform the desired operation on the WebElement.

On similar lines, to click on a WebElement, we generally use the click() method:

At times, the click() method may not work on all the web browsers, or the web controls might behave differently on different browsers. To overcome such situations, the JavaScriptExecutor should be used.

As we know, browsers have JavaScript implementation inside them and can understand JavaScript commands. Hence, understanding JavaScriptExecutor in Selenium will enable us to perform a range of operations more efficiently.

Basics of JavaScriptExecutor in Selenium

The purpose of this section is to provide a high-level idea about the implementation steps of JavaScriptExecutor in Selenium. For the demonstration, we will be using Java as the preferred programming language.

Let’s take a look at the key steps.

  1. Import the package associated with JavaScriptExecutor:

  2. Use JavaScriptExecutor, create a reference for the interface, and assign it to the WebDriver instance by type-casting it:

  3. Call the executeAsyncScript()/executeScript() methods. For example, the syntax for executeScript() is given below:

    4. Where script is the JavaScript to execute, and args is the arguments to the script, or it may be empty. The return values can be Boolean/Long/Double/String/List/Map/WebElement/Null.

Demo: Using JavaScriptExecutor in Selenium

Before we look at how to use JavaScriptExecuter in Selenium, follow these prerequisites:

  • Install Java Development Kit (JDK).
  • Download Eclipse IDE for Java Developers.
  • Download Selenium Java Client Driver.

After that, create a new project in Eclipse and configure the IDE with WebDriver by adding all the required JAR files to the project. In the test scenario, we will use the LambdaTest eCommerce Playground.

Instead of the local Selenium Grid, we will run the tests on an online Selenium Grid offered by cloud testing platforms like LambdaTest. It is an AI-powered test execution platform that provides improved scalability, reliability, and better browser coverage since parallel tests can be run on a range of browser and OS combinations.

Info Note

Automate Selenium tests across 3000+ environments. Try LambdaTest Today!

You can effortlessly migrate the Selenium tests running on a local Selenium Grid to the LambdaTest Selenium Grid through a few additional configurations. After creating a LambdaTest account, make a note of the Username and Access Key available in your Account Settings > Password & Security.

The browser capabilities are generated using the LambdaTest Automation Capabilities Generator.

Test Scenario 1:

Our objective is to write a simple code to illustrate an example using the executeScript() method using the following test scenario.

  1. Navigate to the Account Login page of the LambdaTest eCommerce Playground website.
  2. Enter valid login credentials and click on the Login button by highlighting the field with a red border.
  3. Print the page title and domain name.
  4. Assert that the page header “My Account” is displayed on successful login.

Implementation:

Create a new TestJavaScriptExecutor class for implementing the test scenario. However, we first need to write the methods for setup and configuration to run the tests on the LambdaTest cloud grid.

Two global variables are created in the test class. The first one is the declaration of the RemoteWebDriver class and another variable status is the String variable that is provided to accordingly change the variable value in the test to mark it as Pass or Fail.

A new setup() method is created that will instantiate an instance of the RemoteWebDriver class and accordingly set the configuration for running the tests on the LambdaTest cloud grid.

github

The capabilities required for running the tests on the LambdaTest cloud grid are provided in the getChromeOptions() method.

This method will set the configuration to run the test on the Chrome browser with the current latest version, i.e., 127 on the Windows 10 platform. It will also set the other capabilities such as project name, build name, test name, etc.

Finally, when the test is executed, the tearDown() method will be called, which will close the RemoteWebDriver session gracefully and update the test status, marking it as pass/fail.

Let’s create a new testJavaScriptExecutorCommand() method in the test class we created in the earlier section.

Code Walkthrough:

The code navigates to the Login page of the LambdaTest eCommerce Playground website. It locates the E-Mail Address field using the id locator strategy. Then, it uses the JavaScriptExecutor command to highlight the border of the E-Mail Address field in red color.

Next, the password field is located, and it is highlighted with a red border. This highlight helps in knowing what steps are getting executed. Likewise, the Login button is located using the CSS Selector strategy, and it is highlighted as well.

Login button is located using the CSS Selector strategy

The page title and domain name are located next using the JavaScriptExecutor and printed on the console.

domain name are located next using the JavaScriptExecutor

Finally, the page header of the My Account page, which is displayed after successful login, is located, and an assertion is performed to check that it displays the text My Account.

Test Execution:

The following screenshot of the test executed on LambdaTest cloud grid. It also shows the details of test execution with granular details like logs, screenshots, video, etc.

test executed on LambdaTest cloud grid

The following screen grab from the test execution video generated by LambdaTest cloud grid shows the E-Mail Address field getting highlighted using JavaScriptExecutor.

field getting highlighted using JavaScriptExecutor

Test Scenario 2:

Our objective is to write a simple code to illustrate an example using the executeAsyncScript() method using the following test scenario.

  1. Navigate to the LambdaTest eCommerce Playground website.
  2. Scroll down to the bottom of the home page.
  3. Assert that the text “FROM THE BLOG” is displayed in the lower section of the page.

Implementation:

Create a new testExecuteAsyncScript() method in the existing text class TestJavaScriptExecutor.

Code Walkthrough:

The code will navigate to the homepage of the LambdaTest eCommerce Playground website. The executeAsyncScript() method of the JavaScriptExecutor will be called next, where it will perform the action to scroll the window. In the executeAsyncScript() method, the scripts executed need to explicitly signal that they are finished by invoking the provided callback() method.

scripts executed need to explicitly signal

After scrolling to the bottom of the window, the text FROM THE BLOG will be located, and an assertion will be performed on it.

Test Execution:

The following screenshot from the LambdaTest Web Automation shows that the test was executed successfully.

LambdaTest Web Automation shows that the test was executed

Commands for Using JavaScriptExecutor in Selenium

Let’s examine some scenarios we could handle using JavaScriptExecutor Interface for Selenium test automation.

  • To click on a button

  • To type text in a text box without using sendKeys() method

  • To handle the checkbox by passing the value as true or false

  • To generate an alert pop window in Selenium WebDriver

  • To refresh the browser window using JavaScript

  • To get the innertext of the entire webpage in Selenium

  • To get the title of the web page

  • To get the domain name

  • To get the URL of a web page

  • To get the height and width of a web page

  • To find a hidden element in Selenium using JavaScriptExecutor

  • To navigate to a different page using JavaScript

  • To perform scroll on an application using Selenium

    • To scroll the page vertically for 500px:

    To scroll the page vertically till the end:

  • Adding an element in the Document Object Model (DOM)

  • To get the shadow root in the DOM

That brings us to the end of this blog on JavaScriptExecuter in Selenium. You can also subscribe to the LambdaTest YouTube Channel to stay updated with the latest tutorials on Selenium test automation and real-life automation use cases.

Conclusion

Selenium has an interface called JavaScriptExecutor that is utilized when WebDriver commands don’t behave as intended. With the help of JavaScriptExecutor, we can use WebDriver to execute JavaScript code on the website, allowing us to handle a variety of tasks in an elegant and effective manner that would otherwise be impossible using only Java.

In this blog, we explored how to use JavaScriptExecutor in Selenium and its different methods. Further, we covered various scenarios to attain an effective solution using different methods along with practical examples.

Frequently Asked Questions (FAQs)

How to sendKeys in Selenium using JavaScriptExecutor?

The Testing Pyramid is a framework that can assist both developers and quality assurance professionals to create high-You can use JavaScriptExecutor with the script arguments[0].value=’your text’; to send keys. Locate the element first, then execute the script with the element as an argument.

How to use XPath in JavaScriptExecutor?

Use document.evaluate() with the XPath string, context node, and type to locate elements. You can then manipulate the elements by integrating the result with JavaScriptExecutor.

How to handle alerts using JavaScriptExecutor?

You can use JavaScriptExecutor to trigger or dismiss alerts by executing scripts like alert(‘message’); for showing alerts or window.alert = function() {}; to disable them during tests.

Faisal Khatri

Faisal is a Software Testing Professional having 14+ years of experience in automation as well as manual testing. He is a QA, freelancer, blogger and open source contributor.

He loves learning new tools and technologies and sharing his experience by writing blogs.

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Faisal Khatri

Faisal is a Software Testing Professional having 14+ years of experience in automation as well as manual testing. He is a QA, freelancer, blogger and open source contributor. He loves learning new tools and technologies and sharing his experience by writing blogs.

Blogs: 39



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