1952622 - devtools/debug/watch doesn't show variables assigned 0 or false - shows (unavailable) instead

Status: RESOLVED FIXED

(DevTools :: Debugger, defect, P2)

Description

[[:jaborandi]]

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:136.0) Gecko/20100101 Firefox/136.0

Steps to reproduce:

1. open new tab
2. open dev tools
3. go to https://ewnjtgouierg.github.io/ffbugs/WatchZeroOrFalse.html - it will open Debugger tab because of a debugger directive
4. add these in Watch pane:
   a
   b
   c
   d
   a+1
   a===0

Actual results:

a: (unavailable)
b: (unavailable)
c: null
d: 1
a+1: 1
a===0: true

Expected results:

a: 0
b: false
c: null
d: 1
a+1: 1
a===0: true

Comment 1

[BugBot [:suhaib / :marco/ :calixte]]

The Bugbug bot thinks this bug should belong to the 'DevTools::Debugger' component, and is moving the bug to that component. Please correct in case you think the bot is wrong.

Comment 2

[[:jaborandi]]

behavior is the same when you stop execution with debugger before the assignment and step through it

Comment 3

[[:jaborandi]]

same with stopping on a regular breakpoint

Comment 4

[Hubert Boma Manilla (:bomsy)]

Looks like this relates around
https://searchfox.org/mozilla-central/rev/b0e8e4ceb46cb3339cdcb90310fcc161ef4b9e3e/devtools/client/debugger/src/utils/expressions.js#48-50

We could be better at handling falseys

Comment 5

[Holger Benl [:hbenl]]

It's actually due to !valueGrip on this line: https://searchfox.org/mozilla-central/rev/b0e8e4ceb46cb3339cdcb90310fcc161ef4b9e3e/devtools/client/debugger/src/utils/expressions.js#54

Comment 6

[Holger Benl [:hbenl]]

Note that empty strings are also shown as unavailable.
Simplified STRs:

• open devtools
• add a (constant) watch expression 0, false or ""

Comment 7

[Holger Benl [:hbenl]]

Attachment: Bug 1952622 - [devtools] Don't show falsy values as unavailable in the watch expressions panel. r=#devtools-reviewers,nchevobbe

Comment 8

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/3b5132ab4e0c
[devtools] Don't show falsy values as unavailable in the watch expressions panel. r=nchevobbe,devtools-reviewers

Comment 9

[Serban Stanca [:SerbanS]]

https://hg.mozilla.org/mozilla-central/rev/3b5132ab4e0c