Recently, I've been incorporating the JavascriptExecutor class in my Selenium code to take advantage of JavaScript's efficient DOM manipulation abilities. I rely on XPaths to pinpoint elements, and this line of code showcases how JavaScript deals with XPaths (where 'xpath' represents the desired XPath string):
document.evaluate(xpath, document, null, XPathResult.FIRST_ORDERED_NODE_TYPE, null).singleNodeValue;
For the most part, this approach has been effective in the JavascriptExecutor for all XPaths except one instance:
WebDriver driver = new ChromeDriver();
driver.get("example.com");
JavascriptExecutor js = (JavascriptExecutor) driver;
String xpath = "(//div[@class='aclass']//a)[2]";
String javascript = "return document.evaluate(arguments[0], document, null, XPathResult.FIRST_ORDERED_NODE_TYPE, null).singleNodeValue";
WebElement element = js.executeScript(javascript, xpath);
element.click();
The same XPath used above functions flawlessly in the browser console, but not within the JavascriptExecutor. One notable difference is the "[2]" index component. Surprisingly, if the index is changed to "[1]", it operates successfully in the JavascriptExecutor; however, any value higher than that, such as "[2]", "[3]", or beyond, fails to execute. These higher indices work seamlessly in the browser console.
This leads me to ponder: "Why does this piece of Javascript code, which clearly performs well in the browser console, struggle within the JavascriptExecutor?"
In terms of my DOM structure, I have 6 <a> elements sharing a common parent element <div class='aclass'>. While the JavaScript accurately displays each of the 6 elements in the browser console based on their respective indices using the XPath
"(//div[@class='aclass']//a)[index]"