how to handle unhandled async function exception?

[fsz1987]

I'm using Clearscript v8 .

by default, if an async function throws an error and the caller did not await it.
then the exception is omitted like nothing happened.

example:

//index.js
async function do_some_error (){
    throw new Error ("error!");
}

do_some_error ();

//... some other stuff

is there any way to setup a global hook to handle unhandled async function exception/Promise rejection ?

I hope I can do some fallback process.
for example, print error message and stack trace to the console.

[ClearScriptLib]

Hi @fsz1987,

is there any way to setup a global hook to handle unhandled async function exception/Promise rejection ?

No, but it's something we could look into. What would this feature look like, ideally? For example, are you envisioning a script event, a managed callback, or something else?

[fsz1987]

I hope there could be a managed callback or event.
as a host program, if I need handle this in script. I can expose it to the script easily.

[ClearScriptLib]

Hi again @fsz1987,

I hope there could be a managed callback or event.

We've taken a quick look, and it appears doable.

However, unlike .NET's UnobservedTaskException event, V8's callback is synchronous with promise rejection. That means that simply calling Promise.reject would trigger the callback, and it would be a relatively expensive one due to the transition to managed code.

Would that still be useful to you? If so, V8 offers additional callbacks related to promises:

• Handler added after rejection
• Settled promise resolved
• Settled promise rejected

Would any of those be interesting to you?

Thanks!