910696 - Further expand the variables view when appropriate

Status: RESOLVED DUPLICATE of bug 1448166

(DevTools :: Debugger, defect, P5)

Description

[Nick Fitzgerald [:fitzgen] [⏰PST; UTC-8]]

It is annoying that when I go into a new frame, only the youngest environment is expanded in the variables view. Often it is a block scope with only one or two bindings. We should expand all the environments, so that you can actually see the bindings.

Comment 1

[Panos Astithas (he/him) [:past] (please ni?)]

Note that doing that would make things slower, obviously. But maybe if we just omit the global scope it will be OK. Some experimentation is warranted.

Comment 2

[Nick Fitzgerald [:fitzgen] [⏰PST; UTC-8]]

Victor and I talked about continuing to expand frames while the total number of variables shown was less than N (excluding the global scope, of course). I think this is a pretty good way to control (and experiment with) the performance trade off.

Comment 3

[Victor Porof [:vporof][:vp]]

From what I talked to Nick in Paris, a better plan would be to use some heuristics, not just blindingly expand all environments all the time.

We should keep the current behavior, expect the following cases, in which it'd be helpful if we expanded everything (maybe not the global scope though?):
* selecting a different stackframe
* having less than n enumerable variables in the local scope
* (?) if the local scope is a |with| environment

Comment 4

[Nick Fitzgerald [:fitzgen] [⏰PST; UTC-8]]

I'm unassigning myself because I won't be working on this anytime soon.

Comment 5

[Victor Porof [:vporof][:vp]]

I fixed this in bug 758157 (but entirely accidentally, so without taking into consideration my own fears, described from comment 3), and quickly realized that it can be a significant performance regression in some cases, which I fixed in bug 952767.

All I can say is, let's be very careful when actually fixing this bug :)

Comment 6

[Jason Laster [:jlast]]

closing as I believe it is addressed by bug 1448166