967946 - Add a convenience function to create an exception from a nsresult

Status: NEW

(Core :: DOM: Core & HTML, defect, P5)

Description

[Nikhil Marathe [:nsm] (No longer reading bugmail, please needinfo?)]

A lot of the new APIs require Promises to be rejected on error. If this error is due to underlying XPCOM stuff, I'd like a nice way to get an exception object from the nsresult. The XPCOM machinery that allows functions to return an NS_ERROR_FAILURE and have a nice exception thrown in JS, but without actually throwing it. Then you could just promise->MaybeReject(cx, val) the exception.

I'm not sure how to actually do this.

Comment 1

[Boris Zbarsky [:bzbarsky]]

See dom/bindings/Exceptions.cpp, in particular mozilla::dom::Throw and ThrowExceptionObject.

We could refactor that to have a method that creates the Value and returns it that you could use.  Throw() and company would then call that method and then JS_SetPendingException on the result.

Comment 2

[Firefox Bug Husbandry Bot]

https://bugzilla.mozilla.org/show_bug.cgi?id=1472046

Move all DOM bugs that haven’t been updated in more than 3 years and has no one currently assigned to P5.

If you have questions, please contact :mdaly.