How to use createHandlers method of org.openqa.selenium.grid.commands.Standalone class

Try to wait until element that gets click disappeared:

new WebDriverWait(driver, 10).until(ExpectedConditions.invisibilityOfElementLocated(By.xpath('//div[@style="position: absolute; left: 0px; top: 0px; width: 100%; height: 100%; z-index: 30; background-color: rgb(221, 221, 221); opacity: 0.4;"]')));

As this answer was downvoted, I add some more details to explain why it could be acceptable solution.

It's a known issue (I personally have faced it few times) of chromedriver: chromedriver sometimes ignores modal windows such as "Page loading in progress"

and "thinks" that target element (that is covered by modal window) actually visible and clickable and tries to make click which is received by modal window.

So it makes sense to wait until modal window disappeared.

It's an interesting approach, but I'm concerned you might be masking other issues. I'd prefer to work more closely with the developers to avoid breaking UI issues in the first place.

Are the changing IDs dynamically produced? If that's the case, look to see if you can't get a suffix on the IDs, something like _loginlink. You might also have to work with an XPath that starts from a nearby static ID: "//div[@id='login_link_container'/a". (Starting from the root of the document like your example shows is a recipe for pain! :) )

You can switch between windows as below:

// Store the current window handle
String winHandleBefore = driver.getWindowHandle();

// Perform the click operation that opens new window

// Switch to new window opened
for(String winHandle : driver.getWindowHandles()){
    driver.switchTo().window(winHandle);
}

// Perform the actions on new window

// Close the new window, if that window no more required
driver.close();

// Switch back to original browser (first window)
driver.switchTo().window(winHandleBefore);

// Continue with original browser (first window)

These cases are usually when Firefox & Selenium are a little "out of sync" in terms of compatibility.

You should try two things: update Selenium to the latest one and/or downgrade Firefox. Keeping an eye on the Selenium Release Notes

The WebElementWait class as metioned above:

package org.openqa.selenium.support.ui;

import java.util.concurrent.TimeUnit;

import org.openqa.selenium.NotFoundException;
import org.openqa.selenium.WebElement;

public class WebElementWait  extends FluentWait<WebElement>  {
    public final static long DEFAULT_SLEEP_TIMEOUT = 500;

      public WebElementWait(WebElement element, long timeOutInSeconds) {
            this(element, new SystemClock(), Sleeper.SYSTEM_SLEEPER, timeOutInSeconds, DEFAULT_SLEEP_TIMEOUT);
      }

      public WebElementWait(WebElement element, long timeOutInSeconds, long sleepInMillis) {
            this(element, new SystemClock(), Sleeper.SYSTEM_SLEEPER, timeOutInSeconds, sleepInMillis);
      }

      protected WebElementWait(WebElement element, Clock clock, Sleeper sleeper, long timeOutInSeconds,
              long sleepTimeOut) {
            super(element, clock, sleeper);
            withTimeout(timeOutInSeconds, TimeUnit.SECONDS);
            pollingEvery(sleepTimeOut, TimeUnit.MILLISECONDS);
            ignoring(NotFoundException.class);
      }

}

It's the same as WebDriverWait, except that the WebDriver argument is replaced with WebElement.

Then, the isValid method:

//import com.google.common.base.Function;
    //import org.openqa.selenium.TimeoutException;

public boolean isValid(WebElement e) {
    try {
        WebElementWait wait = new WebElementWait(e, 1);
        //@SuppressWarnings("unused")
        //WebElement icon = 
        wait.until(new Function<WebElement, WebElement>() {
                    public WebElement apply(WebElement d) {
                        return d.findElement(By
                                .xpath("./following-sibling::div[class='invalid-icon']"));
                    }
                });
        return false;
    } catch (TimeoutException exception) {
        return true;
    }
}

The WebElementWait class as metioned above:

package org.openqa.selenium.support.ui;

import java.util.concurrent.TimeUnit;

import org.openqa.selenium.NotFoundException;
import org.openqa.selenium.WebElement;

public class WebElementWait  extends FluentWait<WebElement>  {
    public final static long DEFAULT_SLEEP_TIMEOUT = 500;

      public WebElementWait(WebElement element, long timeOutInSeconds) {
            this(element, new SystemClock(), Sleeper.SYSTEM_SLEEPER, timeOutInSeconds, DEFAULT_SLEEP_TIMEOUT);
      }

      public WebElementWait(WebElement element, long timeOutInSeconds, long sleepInMillis) {
            this(element, new SystemClock(), Sleeper.SYSTEM_SLEEPER, timeOutInSeconds, sleepInMillis);
      }

      protected WebElementWait(WebElement element, Clock clock, Sleeper sleeper, long timeOutInSeconds,
              long sleepTimeOut) {
            super(element, clock, sleeper);
            withTimeout(timeOutInSeconds, TimeUnit.SECONDS);
            pollingEvery(sleepTimeOut, TimeUnit.MILLISECONDS);
            ignoring(NotFoundException.class);
      }

}

It's the same as WebDriverWait, except that the WebDriver argument is replaced with WebElement.

Then, the isValid method:

//import com.google.common.base.Function;
    //import org.openqa.selenium.TimeoutException;

public boolean isValid(WebElement e) {
    try {
        WebElementWait wait = new WebElementWait(e, 1);
        //@SuppressWarnings("unused")
        //WebElement icon = 
        wait.until(new Function<WebElement, WebElement>() {
                    public WebElement apply(WebElement d) {
                        return d.findElement(By
                                .xpath("./following-sibling::div[class='invalid-icon']"));
                    }
                });
        return false;
    } catch (TimeoutException exception) {
        return true;
    }
}

I'm sure Florent B's solutions are viable, but for retro-fitting an old test, I found that zoonabar's solution posted to this duplicate question is easier to implement, takes considerably less code, and requires no special preparation of the test box. It also seems that it would be easier to follow for new developers looking at the code.

In short: visiting any URL with credentials before visiting the URL under test (without credentials) will cause the browser to remember the credentials.

goTo("http://user:password@localhost"); // Caches auth, but page itself is blocked
goTo("http://localhost"); // Uses cached auth, page renders fine
// Continue test as normal

This may feel like a vulnerability in the browser which will be patched, but I think this is unlikely; the restriction has been imposed to avoid phishing risks (where the username chosen looks like a domain, e.g. "http://google.com:long-token-here-which-makes-the-real-domain-disappear@example.com/"), and this workaround for setting credentials doesn't pose the same risk.

See zoonabar's answer

You have to use System.setProperty not the System.getProperty as follows.

System.setProperty("webdriver.gecko.driver",
                "C:\\Selenium WebDriver\\geckodriver\\geckodriver-v0.17.0-win64\\geckodriver.exe");

There are two ways to debug. You can get Page Source and check what is different.

Now when you launch a browser using Selenium, it is using the Debugging session to automate chrome. So you can't do a remote debugger to your website using this.

You need to launch chrome manually.

chrome --headless --remote-debugging-port=9222 --disable-gpu http://tarunlalwani.com

Now in open another chrome and debug the site by going to http://127.0.0.1:9222 and inspect the site.