core_ng/@strpc/def/src/clientAPIPathGen.ts

export function clientAPIPathGen<T extends object, V>(
    obj: T,
    callback: (path: string[], tail: V) => unknown,
    path: string[] = [],
): T {
    const map = new Map<string, unknown>();
    return new Proxy(obj, {
        get(target, key) {
            if(typeof key === 'symbol'){
                throw new Error('Symbol is not supported');
            }

            const cachedResult = map.get(key);
            if(cachedResult !== undefined){
                return cachedResult;
            }

            const nextPath = [...path, key];

            let next;
            if (key in target) {
                next = target[key as keyof typeof target];
            }
            else {
                throw `${nextPath} is not exists`;
            }

            if (typeof (next) === 'function') {
                const result = callback(nextPath, next as V);
                map.set(key, result);
                return result;
            }
            const result = clientAPIPathGen<object, V>(next as object, callback, nextPath);
            map.set(key, result);
            return result;
        }
    }) as T;
}