swaf/src/Extendable.ts

import {Type} from "./Utils.js";

export default interface Extendable<ComponentClass> {
    as<C extends ComponentClass>(type: Type<C>): C;

    asOptional<C extends ComponentClass>(type: Type<C>): C | null;

    has<C extends ComponentClass>(type: Type<C>): boolean;

    /**
     * @throws MissingComponentError
     */
    require<C extends ComponentClass>(type: Type<C>): void;
}

export class MissingComponentError<ComponentClass> extends Error {
    public constructor(type: Type<ComponentClass>) {
        super(`Required component ${type.name} was not found.`);
    }
}