Type error when using useResource

[nightire]

First of all, I can not write a failing test because in test cases, we instantiate the resource class directly, but the type error is caused by useResource utility function.

Then I spend a little time investigating what's going on with useResource, here when describing the arguments of Constructable, I found:

export interface Constructable<T = unknown> {
    new (...args: unknown[]): T; // <- `unknown` causes the type error
}

If I change it to any[] or more precisely (Positional | Named)[], the problem will be solved, at least for my case. I'm not sure if this fix is correct, @NullVoxPopuli how do you think?

[NullVoxPopuli]

Ah! That could be it. Yeah, I'd be happy with any there. It more or less is the same in this case anyway

[NullVoxPopuli]

does Positional<[Field[]]> work?

upon closer inspection, it looks like you are passing an array of fields, but the type of the positional params is 0..n fields, which would be invoked as useResource(this, PreviewGrid, () => [...this.selectedFields[) (note the spread)

tldr:
Positional<Field[]>: useResource(this, PreviewGrid, () => [...this.selectedFields[)
Positional<[Field[]]>: useResource(this, PreviewGrid, () => [this.selectedFields[)

[nightire]

does Positional<[Field[]]> work?

Unfortunately Positional<[Field[]]> still causes the same type error.

[NullVoxPopuli]

I made this demo, of what I thought was the issue, and the type checking passes: #49

Does this help?

[nightire]

I made this demo, of what I thought was the issue, and the type checking passes: #49

Does this help?

Nope.

I'm starting to think maybe it's my side's problem, maybe I need to try in a new ember app instead.

[NullVoxPopuli]

Lemme know how it goes!

[nightire]

@NullVoxPopuli I can confirm the types are correct in a new ember app, now I need to figure out the problem of my side. Thank you anyway.

[nightire]

@NullVoxPopuli I reopen this issue because I found the root cause; I got this error before because I set "strict": true in tsconfig.json, ember-cli-typescript doesn't use this flag by default, but our company follows a more strict policy.

Since "strict": true means to enable a wide range of type checking, I try to toggle them one by one, and I'm pretty sure "strictFunctionTypes": true will lead to this error. According to its documentation, I think it does make sense:

When enabled, this flag causes functions parameters to be checked more correctly.

[github-actions]

🎉 This issue has been resolved in version 1.3.1 🎉

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

Your semantic-release bot 📦🚀

[NullVoxPopuli]

@nightire do you happen to have a reproduction repo?

[nightire]

@NullVoxPopuli Sorry for the delay, I've got caught up in something else this last month.

Here is a reproduction: https://github.com/nightire/ember-resources-type-issue/tree/main#ember-resources-type-issue, hope it can help you.

[github-actions]

🎉 This issue has been resolved in version 3.2.1 🎉

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

Your semantic-release bot 📦🚀

[NullVoxPopuli]

@nightire can you try this latest release?, 3.2.1?

[nightire]

@nightire can you try this latest release?, 3.2.1?

Unfortunately, the error remains. I can live with "strictFunctionTypes": false for now.

[NullVoxPopuli]

Does the error in your reproduction go away?
What's the reproduction missing? 🤔

[nightire]

Does the error in your reproduction go away?
What's the reproduction missing? 🤔

I have upgraded the ember-resources in my reproduction, and the error remains.

This repro is a brand new v3.28.0 ember application with the latest ember-cli-typescript and ember-resources, nothing else.

BTW, this small change will solve the error as I mentioned at the beginning of this issue. Is it an acceptable solution? I'm not an expert on typescript, just ask for curiosity.

export interface Constructable<T = unknown> {
-  new (...args: unknown[]): T;
+  new (...args: any[]): T;
}

[lougreenwood]

I also just hit this issue after enabling strict TS mode.

[nightire]

I also just hit this issue after enabling strict TS mode.

You can use strict mode with strictFunctionType off:

  "strict": true,
  "strictFunctionTypes": false,

I found this setting is not that important as we thought it would be, according to the official document:

During the development of this feature, we discovered a large number of inherently unsafe class hierarchies, including some in the DOM. Because of this, the setting only applies to functions written in function syntax, not to those in method syntax

[NullVoxPopuli]

fixed via... deprecation 😅

better alternative landed in v4.5