Show exception widget for promise rejection

[roblourens]

I set different StoppedEvent reasons for exceptions vs promise rejections, and we should show the exception widget for promise rejections too. From #21905

It seems like it's currently only shown when reason === 'exception', but it should be shown either whenever the exception text is set, or when reason === 'promise rejection'

[weinand]

Let's do this after I've added support for a "robust reason attribute" to the DAP (currently the "reason" attribute is localized).

[weinand]

@roblourens I'm a bit reluctant to hardcode an additional StoppedEvent reason into the VS Code frontend. Could you try to use "exception" reason for promise rejections and use the new "description" attribute for conveying the "Promise Rejection" to the UI?

With the "robust reason attribute" work "reason" is no longer shown in the UI if a "description" attribute is present.

[jrieken]

@roblourens @weinand While this seems to work the information seems to be pretty useless. I understand that in this case rejection happens with null but at least the error message should talk about 'Rejected Promise' instead of 'Exception has occurred: null'

[weinand]

@michelkaporin we do not seem to show the "description" attribute when it's available. Its value would be "Promise Rejection" in this case (and this already shows in the CALL STACK view).

The "description" should take precedence over the fallback message "Exception has occurred".

[michelkaporin]

@weinand we do surface description attribute in exception widget. I can see that 'null' is coming from DA for description, and it is surfaced in UI as-is.

[weinand]

Ok, I've tweaked the use of the "description" attribute in node-debug.

Here is how it looks now for different values passed to reject():

BTW, the missing stacktrace bug is tracked in #25555

[weinand]

To align better with the "inspector" debugger, I've changed the wording from "Rejected Promise" to "Promise Rejection":