Using ExecuteAsyncScript - WebDriverTimeoutException and not seeing the arguments

[gerrald...@gmail.com]

Hello,

I'm new to webdriver so the question might already be answered but I've not found it here

I need help in understanding usage of ExecuteAsyncScript. Currently the simple test with it gets WebDriverTimeoutException and argument is undefined

IJavaScriptExecutor js = Driver as IJavaScriptExecutor;
Driver.Manage().Timeouts().SetScriptTimeout(TimeSpan.FromSeconds(20));

js.ExecuteAsyncScript(
                "console.log('Starting'); setTimeout( function() { console.log('From timeout: '+ document.URL + arguments[arguments.length - 1]) }, 600); console.log('After .....'); ", 10);          

Thanks

[Mark Collin]

The JavaScript you are executing needs to return a callback (See https://developer.mozilla.org/en-US/docs/Mozilla/js-ctypes/Using_js-ctypes/Declaring_and_Using_Callbacks).

Selenium will wait for up to the ScriptTimeout time for the JavaScript you have executed to make a callback, if it doesn't detect a callback it will time out.

[David]

I don't use executeAsyncScript() myself, but from looking at the OP's post and Mark's response, it would seem the OP is attempting functionality similar to example #1 found under 

https://seleniumhq.github.io/selenium/docs/api/java/org/openqa/selenium/JavascriptExecutor.html#executeAsyncScript-java.lang.String-java.lang.Object...-

e.g. use of setTimeout(), although the OP's implementation might not be implemented correctly.

Mark, any tips for the OP in terms of reworking their setTimeout() implementation to be like the Selenium example? I assume they probably have to wrap the before & after console logs along with the setTimeout call and insert a callback somewhere in there.

[Mark Collin]

I would have called Example one a synchronous example because the code isn't going to return until the timeout has completed, I also don't see an explicit callback  (I am not a JavaScript developer though, so there may be something about setTimeout I'm unaware of).

The other examples explicitly define a callback.