Hello Fuxiang, thanks for your interest in Apache Commons Email.
I don't see a reason to add the add a null check here. We're talking about a test class and we know that the VALID_EMAILS array will never be null. Adding a null check just clutters the test code and makes it harder to understand. The reference you've provided is a completely different use case. Just because somebody on StackOverflow implemented a tower defense game that throws a NPE in a for loop doesn't mean all for loops in the world have to be null checked :-) If your looking for code quality metrics, you should have a look at tools like FindBugs [1], PMD [2] and SonarQube [3] and the rules they implement. Best regards and good luck with your studies, Benedikt [1] http://findbugs.sourceforge.net/ [2] http://pmd.sourceforge.net/ [3] http://www.sonarqube.org/ 2014-07-21 0:32 GMT+02:00 Fuxiang Chen <[email protected]>: > Dear Developers, > > We are a team of researchers from the Hong Kong University of Science and > Technology (HKUST). Currently, we are studying how crowdsourcing can help > developers to build a higher quality software. > > One of the subjects that we used is Apache Commons Email. From our > experiment, we identified a few areas in a particular file "EmailTest.java" > that might be proned to NullPointerException being thrown. > > The following 7 methods are identified as "NullPointerException Prone": > 1) testAddToWithEncoding() > 2) testAddTo2() > 3) testAddCc2() > 4) testAddBccWithEncoding() > 5) testAddBcc2() > 6) testAddReplyToWithEncoding() > 7) testAddReplyTo2() > All the above methods encompassed a for loop that checks for the length of > the object > "VALID_EMAILS" in its condition. > > Our reference from the Stack Overflow community pointed out that a null > check to the object of a for loop is preferred to prevent the occurrence of > NPE. The Stack Overflow reference to this is at " > http://stackoverflow.com/questions/10565323";. > > We would like to propose an additional change for your kind consideration: > 1) Having an extra assertion to check if the object "VALID_EMAILS" is null > > By having this new assertion, unnecessary NPE can be avoided. > > We hope that you can consider this and let us know about any thoughts. This > will be a tremendous help to us in our continuing research to building a > better software and to help the open-source community as a whole. > > Please do not hesitate to contact me @ [email protected] if there are any > queries. > > Thanks a lot and have a great week ahead! > > -- > Warmest Regards, > Fuxiang > -- http://people.apache.org/~britter/ http://www.systemoutprintln.de/ http://twitter.com/BenediktRitter http://github.com/britter
