813172 - Evaluating 'arguments' as a watch expression always yields an empty pseudo-array

Status: RESOLVED FIXED

(DevTools :: Debugger, defect)

Comment 1

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

Attachment: v1

Comment 2

[Rob Campbell [:rc] (:robcee)]

Comment on attachment 683149 [details] [diff] [review]
v1

that's probably accurate, isn't it? Since we're evaling inside the scope of that function, arguments is likely just an empty array. Not sure we need to special-case this or not.

Comment 3

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

(In reply to Rob Campbell [:rc] (:robcee) from comment #2)
> Comment on attachment 683149 [details] [diff] [review]
> v1
> 
> that's probably accurate, isn't it? Since we're evaling inside the scope of
> that function, arguments is likely just an empty array. Not sure we need to
> special-case this or not.

Well, what we're doing is a hack (avoid multiple client evaluation requests), and we shouldn't expose this fact. Neither Chrome nor Firebug has this behavior.

Comment 4

[Rob Campbell [:rc] (:robcee)]

Comment on attachment 683149 [details] [diff] [review]
v1

alrighty then. Maybe this is worthy of a comment around the arguments argument and the regex to help future generations.

Comment 5

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

(In reply to Rob Campbell [:rc] (:robcee) from comment #4)
> Comment on attachment 683149 [details] [diff] [review]
> v1
> 
> alrighty then. Maybe this is worthy of a comment around the arguments
> argument and the regex to help future generations.

Thanks. The regex was there before this patch, but ok.

Comment 6

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

Attachment: v1.1

Added comments.

Comment 7

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

https://hg.mozilla.org/integration/fx-team/rev/56f72c68233a

Comment 8

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

https://hg.mozilla.org/mozilla-central/rev/56f72c68233a

Comment 9

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

Comment on attachment 683552 [details] [diff] [review]
v1.1

[Approval Request Comment]
Bug caused by (feature/regressing bug #): Although a remote use case, evaluating "arguments" (incorrectly) yields an empty pseduo-array.
User impact if declined: Almost none, this patch affects a developer tool, however it's a brand new feature that is likely to get some attention.
Testing completed (on m-c, etc.): fx-team and m-c
Risk to taking this patch (and alternatives if risky): None.
String or UUID changes made by this patch: None.

Comment 10

[Lukas Blakk [:lsblakk] use ?needinfo]

New feature, low risk, developer tools only, approving.

Comment 11

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

https://hg.mozilla.org/releases/mozilla-aurora/rev/83fbb172185e