1380711 - Investigate in showing Promise update in the Object inspector

Status: RESOLVED FIXED

(DevTools :: Object Inspector, enhancement, P3)

Description

[Oriol Brufau [:Oriol]]

1. Open the new console frontend
2. Enter new Promise(f => setTimeout(f, 0))
3. The preview shows Promise { <state>: "pending" } because the promise didn't resolve immediately
4. Expand the promise

Result: it still says <state> : "pending", but now the promise has been resolved.

This didn't happen with variablesview, e.g.

 > var p = new Promise(f => setTimeout(f, 0)); p;
   Promise { <state>: "pending" }
 > inspect(p);

Comment 1

[Nicolas Chevobbe [:nchevobbe]]

I am not sure if this should be considered as a bug here.
If we wanted to be more fair, we should compare 

```new Promise(f => setTimeout(f, 0))```

with

```inspect(new Promise(f => setTimeout(f, 0)))```

or 

```
> p = new Promise(f => setTimeout(f, 0));
> p;
```

with

```
> p = new Promise(f => setTimeout(f, 0));
> inspect(p);
```

Because in the latter case, you give time to the Promise to be resolved.
If we compare apples to apples, the Object Inspector and the VariableView behaves the same way.
Which I think is the correct way since logging show you the value of an object at the specific time you logged it.

What we could think about though, is having a way to tell the user that an object was updated and add a reload/refresh button on it so the user can see the new value.
I am not sure if this is useful for all objects, but promise might be a good candidate for this.

I am a bit concerned too of the performance cost that this would introduce if we start watching for every update on every logged object.

Comment 2

[Nicolas Chevobbe [:nchevobbe]]

Moving to the DOM panel as it's VariableView related and only the DOM panel uses the VariableView now

Comment 3

[Nicolas Chevobbe [:nchevobbe]]

erratum: this should have been moved to the storage inspector, which is the last consumer of the variable view

Comment 4

[Nicolas Chevobbe [:nchevobbe]]

since it's only used in Storage, the VariableView doesn't ever display Promises

Comment 5

[Oriol Brufau [:Oriol]]

This is unrelated to storage. The problem was that, when expanding a resolved promise which was still pending when creating its preview, it would still be shown as pending.

This was inconsistent with what happens when expanding the result of

var o = {};
setTimeout(() => {o.a = 1}, 100);
o;

I fixed the problem as a side effect of bug 1552648.