Improve Component types to allow for type inference on schema properties

[brmenchl]

These changes should enable type inference on component schema properties, while not changing the way Components are constructed.

Now when using Typescript and creating a component like: class Position extends Component<{ x: number, y: number }>{} for any new instance of Position typescript will recognize all base Component properties, as well as the properties specified in the Component generic type parameter (the schema). (in this case, new Position().x will resolve to number)

Example usage (type declarations copied from PR)

Fixes #249

[ulyssesdotcodes]

Does this work with Entity.d.ts? I think taking out the generic from ComponentConstructor makes it more difficult to getComponent

[brmenchl]

@ulyssesp Good catch. I modified component types to allow parametrizing component constructors. For now, there are new two type entry points. One, where you know the schema type already (referencing existing Component constructors, you can now reference ComponentConstructor), and two, where you don't (now this is just called ComponentStatic, and only the constructor function new is parametrized).

[brmenchl]

I also added simple type tests to the repo to show usage, and updated all type files to reference the correct types

[brmenchl]

Typescript playground link with updated PR types here

[DavidPeicho]

Pretty cool. The only thing is that at the end we duplicate the type information in the extends and schema. I am wondering if it would be possible to directly use the schema.

[brmenchl]

In Typescript, The static members of a generic class can never refer to the class's type parameters, so we can't reference back and forth from scheme to the type parameters, we have to duplicate.

https://microsoft.github.io/TypeScript-New-Handbook/chapters/classes/#type-parameters-in-static-members

[brmenchl]

@robertlong (or some other maintainer), are we good to merge this?