Caveats to using RouteTemplate as decorator?

[IgnaceMaes]

Been very much enjoying using this addon, thanks for creating this!

The documentation in the Readme only documents calling RouteTemplate in the function form. However, I've been using it as decorator and it's been working great. I wonder if this should be documented?

Decorator usage

Example:

// app/templates/index.gjs
import RouteTemplate from 'ember-route-template';
import Component from '@glimmer/component';

// eslint-disable-next-line ember/no-empty-glimmer-component-classes
@RouteTemplate
export default class IndexTemplate extends Component {
  <template>
    Hello {{@model}}!
  </template>
}

I like that it resembles a regular component definition greatly. The downside is that it doesn't work for template-only components, though. In this example it's just a simple template wrapped in the backing class, but that does trigger the ES Lint warning.

TypeScript

TypeScript works, but complains on the return type:

Decorator function return type 'TemplateFactory' is not assignable to type 'void | typeof IndexTemplate'.

// app/templates/index.gts
import RouteTemplate from 'ember-route-template';
import Component from '@ember/component';

interface IndexTemplateSignature {
  Args: {
    model: string;
  }
}

@RouteTemplate
export default class IndexTemplate extends Component<IndexTemplateSignature> {
  <template>
    Hello {{@model}}!
  </template>
}

A hacky patch can be achieved by just adding an override that returns void:

declare module 'ember-route-template' {
  export default function RouteTemplate(Component: object): void;
}

Now TypeScript is happy 😄