相关疑难解决方法(0)

我是单元测试的新手,我不断听到很多东西被抛出的"模拟对象".通俗地说,有人可以解释什么是模拟对象,以及在编写单元测试时它们通常用于什么？

我在Assertionerror中的期望值和实际值都显示相同的内容。它们是相同的参考。有人知道为什么以及如何解决吗？下面的代码和错误。提前致谢：

@Test
public void test_CreateAUserWritesAFileReadsFilePrintsFile() throws IOException {
    //Arrange
    WriteCommand fwc = new FileWriteCommand();
    ReadCommand frc = new FileReadCommand();
    RegistrationController rc = new RegistrationController();
    User user = new User("Jerry", "123", "Engineer");
    rc.registerNewUser("Jerry", "123", "Engineer");
    fwc.writeUser(user);
    User one = frc.readUser("Jerry");
    System.out.println(one);
    User expected = one;

    //Act
    User actual = user;

    //Assert
    assertEquals(expected, actual);

}

错误

java.lang.AssertionError: expected: com.fdmgroup.userregistration.User<User [username=Jerry, password=123, role=Engineer]> but was: com.fdmgroup.userregistration.User<User [username=Jerry, password=123, role=Engineer]>