typescript cheatsheet

resources.md

https://stackoverflow.com/questions/40510611/typescript-interface-require-one-of-two-properties-to-exist

typescript_cheatsheet.ts

type CallbackFunction = () => void;
type CallbackFunctionVariadic = (...args: any[]) => void;
type CallbackFunctionVariadicAnyReturn = (...args: any[]) => any;
type CallbackFunctionSomeVariadic = (arg1: string, arg2: number, ...args: any[]) => void;


// MIXIN

type Constructor<T> = new(...args: any[]) => T;

interface Tagged {
    _tag: string;
}

function Tagged<T extends Constructor<{}>>(Base: T): Constructor<Tagged> & T {
    return class extends Base {
        _tag: string;
        constructor(...args: any[]) {
            super(...args);
            this._tag = "";
        }
    }
}

const TaggedPoint: Constructor<Tagged> & typeof Point = Tagged(Point);

let point: Tagged & Point = new TaggedPoint(10, 20);
point._tag = "hello";



interface Jakis { dupa: number }
function a<T extends Jakis>(x: T) {}
a({dupa: 8, cycki: 9})