UNSAFE_METHOD_ACCESS warning should take into consideration existing "if" statements

[Blocker226]

Hi, I am a junior developer with previous experience in Unity, transitioning to Godot and GDScript. I used to enjoy JetBrains Rider's C# support, which included auto-formatting for safe casting/method access.

Coming to GDScript, I noticed that when I set the warnings/unsafe_method_access setting in the project settings, it does encourage me to use the as keyword to cast my derived classes accordingly, providing some level of validation on par with Rider.

However, it does not take into account the presence of any type of checks that precede it, namely, cases like this, where the class Selectable extends Node3D:

if current_hover && current_hover is Selectable:
    current_hover.set_highlight(true) 
# The method "set_highlight()" is not present on the inferred type "Node3D" (but may be present on a subtype).

I'm hoping it's possible to add some sort of contextualisation to the editor for it to be able to identify such cases, and perhaps open up new opportunities to add auto-suggest/format/fix options down the line.

[AThousandShips]

It does, as far as I know, either this is a bug or a limitation with using custom classes

Does it work if you do:

if current_hover is Selectable:
    current_hover.set_highlight(true)

AFAIK is does null checking too

CC @dalexeev

[Blocker226]

I can confirm that is does null checking, but that code snippet doesn't work either, probably for the reasons @dalexeev mentioned. His workaround does work, but I think this would be nice to look into down the line, at least for style reasons.

Maybe expanding the warning to be able to elaborate on, show or link to workarounds such as these would suffice in the short term?

[miv391]

New variable is not necessarily needed. This should also work:

if current_hover and current_hover is Selectable:
	(current_hover as Selectable).set_highlight(true)

But it would be nice if GDScript had an optional chaining operator ?. like in Typescript. In this example you could write:

(current_hover as Selectable)?.set_highlight(true)

set_highlight would be called only if current_hover as Selectable is not null.

[Blocker226]

@miv391 Yes, but I'm trying to avoid repetitive scenarios like this:

if current_hover and current_hover is Selectable:
    (current_hover as Selectable).set_highlight(true)
    (current_hover as Selectable).on_select()
    # code that relies on Selectable

I do agree that having a conditional access operator would be nice, but that's probably for another discussion.

[dalexeev]

Yes, it is not necessary to create a new variable. But keep in mind that the as operator in this case generates runtime code, so it is more rational to create a variable if you want to use the result several times.

[Mickeon]

Admittedly, it would be nice if the compiler was smarter about this and casted under the hood. I aim to have as many safe lines as possible, but to achieve that an implicit cast is always necessary, which feels redundant for GDScript, specifically.

[mieldepoche]

see also #3691