add types for Resource and @use

[NullVoxPopuli]

Also adds a utility function to get the type of value when using @use

Demo

[josemarluedke]

We definably need to have types here. But for comparison, these are the types I have been using:

declare module 'ember-could-get-used-to-this' {
  interface TemplateArgs {
    positional?: unknown[];
    named?: Record<string, unknown>;
  }

  type Owner = unknown;

  type Thunk<T> = () => T;

  declare class Resource<
    Args extends TemplateArgs = TemplateArgs,
    T = unknown
  > {
    protected readonly args!: Args;
    abstract readonly value: T;

    constructor(ownerOrThunk: Owner | Thunk<Args>, args?: Args): void;

    setup(): void;
    abstract update?(): void;
    abstract teardown?(): void;
  }

  export declare let use: PropertyDecorator;
}

[NullVoxPopuli]

I'll add the lifecycle methods, but:

• value is a getter, rather than a property, so what's in this PR should be sufficient?
• that leaves the constructor: is using the constructor supported?

[NullVoxPopuli]

TypeScript playground Demo added to description

[scottmessinger]

@NullVoxPopuli I thought value could be either a property or a getter, at least that's how we've been using it. Working from @josemarluedke's definition (thanks, @josemarluedke!), here's what I'm doing. I've created a resource to replace our usage of ObjectPromiseProxy's, which we're using to fetch documents from our server.

interface Args {
  positional: [string, string]
}

interface Value<T> {
  isPending: boolean
  isSettled: boolean
  isRejected: boolean
  isFulfilled: boolean
  content: T | null
}

export default class FindDoc<T> extends Resource<Args, Value<T>> {
  value: Value<T> = new TrackedObject({
    isPending: false,
    isSettled: false,
    isRejected: false,
    isFulfilled: false,
    content: null,
  })
  ...

And how it's used:

  @use document = new FindDocument<MyModelName>(() => [
    "my-model-name",
    this.args.model.id,
  ])

This gives me the correct type hinting in the component that consumes this resource. Can we add the ability to type the value even if some people implement value as a getter? It would certainly be useful for us!

[josemarluedke]

@scottmessinger In a recent PR #35 (not yet released), we changed to return the instance of the resource rather than the value. Therefore there is no need to have specific types for the value.

[NullVoxPopuli]

I'm going to close this, because after #37, the typescript stuff would have to be re-done anyway.

Once #37 is merged, I'll convert everything to TS :D

[scottmessinger]

@josemarluedke Just looked through that PR and I'm 💯 . For me, it feels more intuitive. I like it!