I switched some progress events over to the DAP ProgressStartEvent recently but discovered that there's a delay of 500ms before these progress events appear:

And although the ProgressEndEvent takes a "final message", it's never used by VS Code.

The result is that short-lived progress messages (for example hot reloading an app) the message is never shown to the user (this has come up a few times - for example Dart-Code/Dart-Code#2597).

It feels like a debug adapter should have some control over this - right now I need to decide between:

• Doing nothing and having users confused about whether the hot reload ran
• Put a fake delay of 500ms in before sending the ProgressEndEvent - this makes the progress visible, but it's delayed by half a second which is also confusing
• Switching back from DAP requests to using my own custom events and displaying my own progress

I think it would be better if the delay was removed (and left to the DA), reduced, or DAP-provided and the ProgressEndEvent's final message was displayed for a short period after it arrived.

(cc @isidorn - delay was added in a47badb)