deep_proxy.ts

function isObject(value: any): value is object {
  return value !== null && typeof value === 'object';
}

export const DELETED = Symbol();

export function deepProxy(
  original: any,
  handler: (path: string[], value: any | typeof DELETED) => void,
  selfPath: string[] = [],
): any {
  return new Proxy(original, {
    get: (target, prop) => {
      if (Reflect.has(target, prop) && isObject(target[prop])) {
        return deepProxy(target[prop], handler, [...selfPath, prop as string]);
      }
      return target[prop];
    },
    set(target, property, value, _receiver) {
      if (isObject(value)) {
        for (const k of Object.keys(value)) {
          const v = (value as any)[k];
          if (isObject(v)) {
            // @ts-ignore
            value[k] = deepProxy(v, handler, [...selfPath, property as string, k]);
          }
        }
        value = deepProxy(value, handler, selfPath);
      }
      target[property] = value;
      handler([...selfPath, property as string], value);
      return true;
    },
    deleteProperty(target, property) {
      if (Reflect.has(target, property)) {
        const deleted = Reflect.deleteProperty(target, property);
        if (deleted) {
          handler([...selfPath, property as string], DELETED);
        }
        return deleted;
      }
      return false;
    },
  });
}