首先，确保安装了AWS CDK的所有必需模块。然后，可以使用以下代码示例在对象属性上正确地定义Jest测试：

import { expect as expectCDK, haveResource } from '@aws-cdk/assert';
import * as cdk from '@aws-cdk/core';
import { MyStack } from '../lib/my-stack';

test('Test my stack', () => {
  const app = new cdk.App();
  const stack = new MyStack(app, 'MyTestStack');
  expectCDK(stack).to(haveResource('AWS::S3::Bucket', {
    BucketName: '',
    PublicAccessBlockConfiguration: {
      BlockPublicAcls: true,
      BlockPublicPolicy: true,
      IgnorePublicAcls: true,
      RestrictPublicBuckets: true
    }
  }));
});

该代码使用了haveResource方法来检查在AWS S3桶资源上是否定义了正确的属性。此代码示例可以在AWS CDK中正确使用Jest测试对象属性。