1216632 - Make console autocompletion work on $0

Status: VERIFIED FIXED

(DevTools :: Console, defect, P1)

Description

[Brian Grinstead [:bgrins]]

Right now if you run `$0.` in the console you don't get any autocompletion.  However if you do `foo = $0;` then run `foo.` you do.

I think it has to do with the fact that $0 is added as an extra binding for the debugger and the JSPropertyProvider we use for webconsole just looks in the normal environment.

Comment 1

[Sebastian Zartner [:sebo]]

I stumble over this issue every day. This bug limits the usefulness of $0 a lot, because you have to know and type out all the properties by yourself.

Brian, it sounded like you had an idea how to fix this. Could this please get some priority?

Sebastian

Comment 2

[Brian Grinstead [:bgrins]]

I agree this would be a great feature to have. But I don't expect to have the cycles to look into this in the near future as we are focused right now on getting the new console frontend shipped to release.

If someone wanted to look into this, I'd start in the JSPropertyProvider, where we have some special case handing for `this` [0]. I expect we could add something similar for $0.  $0 is special cased in the backend as a WebConsoleCommand [1], and we should be able to do a call similar to what is being done there, if we pass the selected node into it.  In that case, the selectedNode object is created from a property sent from client `selectedNodeActor` [2].

[0]: https://dxr.mozilla.org/mozilla-central/source/devtools/shared/webconsole/js-property-provider.js#228-235
[1]: https://dxr.mozilla.org/mozilla-central/source/devtools/server/actors/webconsole/utils.js#379-383
[2]: https://dxr.mozilla.org/mozilla-central/source/devtools/server/actors/webconsole.js#1344-1349

Comment 4

[Nicolas Chevobbe [:nchevobbe]]

TRY looks good: https://treeherder.mozilla.org/#/jobs?repo=try&revision=e326485dc1f84b8f891c2d0512128eec67b1dbb7

Comment 5

[Nicolas Chevobbe [:nchevobbe]]

Attachment: Bug 1216632 - Make autocompletion work on $_ and $0; r=bgrins.

To make $0 autocompletion work, we need to pass the current
selectedNode actor from the frontend, so we can retrieve the
object reference later.
For $_, we need the webconsole actor reference to be able
to retrieve the last input result.
Since the list of parameters of JsPropertyProviders was
getting a bit long, we transform them in an object so it's
more legible on the consumer side.
Mochitests are added for both helpers to ensure this work
as expected.

Comment 6

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/18eddae8a268
Make autocompletion work on $_ and $0; r=bgrins.

Comment 7

[Eliza Balazs [:ebalazs_]]

https://hg.mozilla.org/mozilla-central/rev/18eddae8a268

Comment 8

[Sebastian Zartner [:sebo]]

I can verify that the autocompletion for $0 and $_ works in Nightly 2018-11-15, while it didn't work in 2018-11-14.

This was one of the major regressions on the transition from Firebug to the DevTools, especially $0. So, thank you very much for this change, Nicolas!

Sebastian