我有以下工厂类：

public class EmployeeFactory {

    public static Employee createEmployee(Employee employee) {

        switch (employee) {
            case DOCTOR:
                return new Doctor();
            case NURSE:
                return new Nurse();
        }

       throw new EmployeeException("Invalid Employee!");
    }

}

• • 枚举类：**

public enum Employee {

    DOCTOR("Doctor"),
    NURSE("Nurse");

    private final String description;

    Employee(String description) {
        this.description = description;
    }

    public String getDescription() {
        return description;
    }
}

我想创建一个模拟枚举，例如TEACHER，它是我的factory方法的无效输入，以Assertexception被抛出。
我怎么能这样做呢？

• • 当前测试：**

@Test
    void shouldThrowException(){

        assertThrows(EmployeeException.class,
                () -> {
                    // arrange
                    //todo - how to?
                    Employee invalidEmployee = mock(Employee.class);
                    when(invalidEmployee.getDescription()).thenReturn("Teacher");

                    // act
                    EmployeeFactory.createEmployee(invalidEmployee);
                });
    }