How can I troubleshoot and resolve the issue of “InvalidSelectorException” error?
I am currently engaged in a particular task that is related to testing a web-based application by using the Selenium WebDriver. I attempted to select a button on the page by its CSS selector, however, when I was running my test, I encountered an “InvalidSelectorException” error which indicates that it is invalid or illegal. What could be the potential reasons for this particular exception and how can I troubleshoot and resolve it?
In the context of selenium, here are the potential reasons and solutions given:-
Syntax errors in the selectors
You should try to ensure that the CSS selector syntax is correct.
Use of multiple IDs in a selector
An element should not have multiple IDs. A CSS selector such as button#login-btn#invalid-selector is invalid because an element cannot have more than one ID.
Unsupported or complex selectors
Certain complex selectors or even the pseudo-element could not be supported by the browser’s native query selector.
Here is the solution given:-
Correct the selector syntax
You can use the CSS selectors. For Instance, if the element has a single ID called “Login -btn” then the selector would be “button#login-btn”.
Simplify the selector
If selecting by I’d, you can directly use the “By.id(login-btn”) which is more straightforward and it can also avoid the CSS selector complexity.
Here is the example given below of how you can correct the CSS selector and properly Interact with the login button:-
Import org.openqa.selenium.By;
Import org.openqa.selenium.WebDriver;
Import org.openqa.selenium.WebElement;
Import org.openqa.selenium.chrome.ChromeDriver;
Public class LoginTest {
Public static void main(String[] args) {
// Set the path to the ChromeDriver executable
System.setProperty(“webdriver.chrome.driver”, “path/to/chromedriver”);
// Initialize WebDriver
WebDriver driver = new ChromeDriver();
Try {
// Open the login page
Driver.get(file:///path/to/login.html);
// Correctly locate the login button using a valid CSS selector
WebElement loginButton = driver.findElement(By.cssSelector(“button#login-btn”));
loginButton.click();
// Alternatively, use By.id to locate the button
// WebElement loginButton = driver.findElement(By.id(“login-btn”));
// loginButton.click();
System.out.println(“Login button clicked successfully.”);
} catch (Exception e) {
// Handle any exceptions that occur
System.out.println(“Exception caught: “ + e.getMessage());
} finally {