Cannot instantiate classes from preflight static methods

[Chriscbr]

I tried this:

bring cloud;

class Foo {
  static makeFunc(): cloud.Function {
    return new cloud.Function(inflight (s: str): str => {
      return "hello world!";
    });
  }
}

let bar = Foo.makeFunc();

test "it works" {
  let result = bar.invoke("");
  assert(result == "hello world!");
}

This happened:

$ wing compile -t sim statics.w       
Cannot read properties of undefined (reading 'root')

I expected this:

It compiles and the test passes

Is there a workaround?

Change the method from a static method to a regular method

Component

Compiler

Wing Version

0.17.7

Wing Console Version

No response

Node.js Version

18.14.1

Platform(s)

MacOS

Anything else?

No response

Community Notes

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[Chriscbr]

I think there are two problems here, one is the mechanical issue (creating a new class is translated into this.node.root.newAbstract(...), and "this" isn't available in static contexts), and the other is a design issue (if you create a preflight class in a static method, what scope does it get added to? do we need static methods to have an implicit "scope" parameter under the hood, a la #287?)

My guess is this is probably not P1 for beta

[github-actions[bot]]

Hi,

This issue hasn't seen activity in 60 days. Therefore, we are marking this issue as stale for now. It will be closed after 7 days. Feel free to re-open this issue when there's an update or relevant information to be added. Thanks!

[github-actions[bot]]

Hi,

This issue hasn't seen activity in 60 days. Therefore, we are marking this issue as stale for now. It will be closed after 7 days. Feel free to re-open this issue when there's an update or relevant information to be added. Thanks!

[Chriscbr]

@skyrpex mentions he would like this capability for creating static factories:

pub class ContainersFactory {
    pub static create(): types.IContainers {
        let driver = util.tryEnv("CONTAINERS_DRIVER") ?? "docker";
        if driver == "docker" {
            return new docker.DockerContainers();
        } elif driver == "fly" {
            return new fly.FlyContainers(
                token: util.env("CONTAINERS_FLY_TOKEN"),
                orgSlug: util.env("CONTAINERS_FLY_ORG_SLUG"),
                region: util.tryEnv("CONTAINERS_FLY_REGION"),
            );
        } else {
            throw "Unknown CONTAINERS_DRIVER: ${driver}";
        }
    }
}

[skyrpex]

From the example above, I'd expect docker.DockerContainers or fly.FlyContainers to inherit the scope where ContainersFactory.create() was called from.

[skorfmann]

was trying something similar

    pub static add(name: str, value: str) {
        new aws.ssmParameter.SsmParameter(
            name: Util.key(name),
            type: "String",
            value: value,
        ) as Util.key(name);
    }

[monadabot]

Congrats! :rocket: This was released in Wing 0.48.12.