如何在返回 void 类型的公共方法中测试局部变量？

Question

My CUT has a public method, "sync()" which returns void and it use some variables like "syncContactEnabled" which they are set using spring and properties file. it is my CUT:

public class ContactSyncServiceImpl implements SyncService {

 public void sync() {
        long start = System.currentTimeMillis();
        logger.info("-----sync() start:{}", start);
        if (!syncContactEnabled) {      //***********first: want to test this if
            logger.info("Contact sync isn't enabled.");
            return;
        }

        SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss", Locale.ENGLISH);
        Date now = new Date();
        Date startDate = null;
        String contactSyncStartDateConfig = configService.get(CONTACT_SYNC_START_DATE);
        if (StringUtils.isBlank(contactSyncStartDateConfig)) {       \\**********second: I want to test startDate value in this if-else
            startDate = new Date(now.getTime() - syncStartDaysCount * 24 * 60 * 60 * 1000l);
        } else {
            try {
                startDate = formatter.parse(contactSyncStartDateConfig);
            } catch (Exception e) {
                logger.warn("There's a problem parsing date:" + e);
            }
        }


/////////It is NOT complite code of class.......(:
}

first question:

• How can I mock some variables like "syncContactEnabled" which it is set in properties file?

second question:

• How can I test internal manner of "sync()" method, for example How can I test "startDate" value in if-else condition?

and finally, it is my properties file:

sync.contact.enabled=false
sync.page.size=100
sync.cron=0 30 6,18 * * ?
#*/1 * * * * *
sync.start.days.count=365

Answer 1

first question:

• How can I mock some variables like "syncContactEnabled" which it is set in properties file?

You don't.

second question:

• How can I test internal manner of "sync()" method, for example How can I test "startDate" value in if-else condition?

You do not either.

When Unittesting you verify public observable behavior that means: What results are returned depending on the input and how does the unit communicate with its dependencies .

The variable 'syncContactEnabled' is an implementation detail that you do not verify. This is because in may change without changing the units behavior and you don't want to change the test in that case.

---

I think, I just can use some test like: PowerMockito.donothing or PowerMockito.verify..... yes???? and I can not test internal manner... – m.mjn202

Avoid PowerMock(-ito) by any chance. In most cases the need of PowerMock(-ito) is a sign of bad design and the lack of dependency injection .

Usually you mock dependencies , other classes your unit communicates with. The only exception is that your unit is an abstract class .

The doNothing(mock).someMethod() configuration is needed, if you mocked a real class (instead of an interface) and you need to prohibit the method ( someMethod() ) to be called (eg because it connects to a database...)