Checker

[EdwardZZZ]

enum E {
    a = 'a',
    b = 'b',
}

class A {
    name: string = 'Zhangsan';

    pw: E = E.a;

    sports: string[] = ['swimming', 'running'];
}

/**
 * is/has fn?
 * @returns 
 */
function Checker<T extends { [key: string]: any }>(obj: T): { [P in keyof T]: { is: T & Record<T[P], boolean>; has: T[P] extends Array<infer U extends string> ? Record<U, boolean> : never } } {
    return new Proxy<T>(obj, {
        get(target: T, field: string) {
            return new Proxy(target, {
                get(target: T, type: string) {
                    return new Proxy(target, {
                        get(target: T, val: string) {
                            const v = obj[field];

                            if (v === undefined) return false;

                            if (type === 'is') return val === v;

                            if (type === 'has') return v.indexOf(val) > -1;

                            return false;
                        },
                    });
                },
            });
        },
    });
}

const a = new A();
console.log(a, Reflect.ownKeys(a));

console.log(Checker(a).name.is.Zhangsan);
console.log(Checker(a).name.is.Lisi);
console.log(Checker(a).pw.is.a);
console.log(Checker(a).pw.is.c);
console.log(Checker(a).pw.has.a);

console.log(Checker(a).sports.has.swimming);