Cannot invoke "org.htmlunit.corejs.javascript.Scriptable.getParentScope()" because "obj" is null

Hi everyone!

I am super excited to see there is something compatible with Selenium that I can use to unit test with. My test works as follows:

In the constructor, I initialize a new WebDriver:

HtmlUnitDriverOptions options = new HtmlUnitDriverOptions(BrowserVersion.CHROME);

options.setJavaScriptEnabled(true)
       .setCapability(HtmlUnitOption.optThrowExceptionOnScriptError, false);

webDriver = new HtmlUnitDriver(options);

Then later on in a different method call, I instruct it to load a static resource. In this case, it is a rendered HTML file from twitter. I then immediately after instruct it to wait for the JavaScript to finish executing by waiting for the root node to finish rendering.

String currentDirectory = System.getProperty("user.dir");
webDriver.get("file:///" + currentDirectory + "/resources/test/web/twitter_source.html");

WebDriverWait jsWait = new WebDriverWait(webDriver, Duration.ofSeconds(20));
jsWait.until(ExpectedConditions.presenceOfAllElementsLocatedBy(By.id("react-root")));

This all works well.

Then even later in the code, I run a JavaScript file that crawls the DOM and adds style attributes to each node. For example:

style-boundingx

When HtmlUnit processes this file, I get the exception or error message in the issue title:

Cannot invoke "org.htmlunit.corejs.javascript.Scriptable.getParentScope()" because "obj" is null

I tried to look up the javadoc for ScriptableObject but I get a 404 and so I cannot debug further. Any indication as to what the issue may be? I don't know what "obj" refers to. This code runs in Java Selenium with a ChromeDriver v127, so the JavaScript script should be fine. This only happens on HtmlUnit.

https://www.htmlunit.org/apidocs/org/htmlunit/corejs.javascript.ScriptableObject.html

Any help is appreciated. Thanks!

Start by reproducing the failure with the HtmlUnitDriverOptions setup and resources/test/web/twitter_source.html, then inspect the later JavaScript file that crawls the DOM and adds style attributes. Compare the behavior with ChromeDriver and trace the null Scriptable involved; done means the same DOM-processing script runs without the reported exception.