如何替换对被测试类的私有方法的调用

Question

好吧，我现在正在测试遗留代码。而且，我已经接近通过这个测试了，但是它被困在了有评论的线路上。这是代码片段

    new NonStrictExpectations(){
        SASCustomerDataAssemblerBD assembleBd;
        CustomerTOs tos;
        CustomerSASTO to;
        Another rowTo;
        SelectionJobLogBD logBd;    

        {
                SASCustomerDataAssemblerBD.getInstanceUsingEjbRef(); result = assembleBd;
                assembleBd.getData(); result = tos;
                ..
                ..
                //This line is not being invoked. 
                //Instead the actual line of code is working. Which is,
                //Collections.max(someCollection, someComparator);
                //Hence I am stuck because getting null in "to"
                invoke(Collections.class, "max", new ArrayList(), new MaxDateComparator()); result = to;
                to.getSasDataRow(); result = rowTo;
                SelectionJobLogBD.getInstanceUsingEjbRef(); result = logBd;                                 
                ..
        }
    };

    new TaskSASCustomerReading().execute(); 

，而 result 的所有值都是模拟的。

Answer 1

解决了，用另一种方式:)。模拟了原始方法——仅在底层调用 Collections.max() 的方法。

    new MockUp<TaskSASCustomerReading>()
    {
        @Mock
        // This original method is invoking Collections.max(). 
        // Therefore, I just mocked this one, other methods are all original
        String findLatestSelectionDate(Collection customerTOs) {
           return "";
        }
    };

    new Expectations(){
        SASCustomerDataAssemblerBD assembleBd;
        CustomerTOs tos;         
        SelectionJobLogBD logBd;
        {
            try {
                SASCustomerDataAssemblerBD.getInstanceUsingEjbRef(); result = assembleBd;
                assembleBd.getData();  result = tos;
                SelectionJobLogBD.getInstanceUsingEjbRef();  result = logBd;                                
            }catch(Exception e){}
        }
    };

    new TaskSASCustomerReading().execute(); 

尽管如此，当我问这个问题时，我一开始就完全误解了这件事。在我原来的问题中，我实际上是在尝试调用一个方法，而不是替换它。 （PS 切勿在下班后工作。;)）