Hi Oleg, Migrating to Junit 4 sounds as great idea. I believe everybody is quite surprised when finds Junit 3 in Ignite. But for me personally it is good to understand what problem we are trying to solve? What benefits will Junit 4 give us? What are the most painful moments with current testing framework? (I my mind I draw a proposal which contains sections "Motivation", "Alternatives", etc.)
Also I must say that I made some experiments related to Junit4 migration. And from the first glance it seems that the most important Ignite test framework classes contain a huge amount of utility methods and a little amount of code related to a test lifecycle. These classes are GridAbstractTest and GridCommonAbstractTest. Both are quite thick, but as already said it is mostly utility code which could be extracted. I would be great to come to very thin base test classes (or even to baseclass-less tests at all) and include all kind of utilities without inheritance. But massive refactoring perhaps is more for future. The main point here is that Ignite test framework is not complex at all and could be easily adopted to Junit 4. Regarding twin classes. How to keep them in sync? If the migration process will be paused halfway it could make things complicated in future. Additionally, I have a wild idea how to marry junit 3 and 4 without introducing twins. The idea looks ugly from OOP perspective, but here it is. We can simply annotate overridden Junit 3 setUp and tearDown methods with @Before and @After annotations. And use runTest overridden method for Junit 3 and TestRule for Junit 4 in order to run test methods in newly started thread. For all details you can see an experiment on github [1]. Among them are ticks with @RunWith annotation making possible to run a test inherited from TestCase as Junit 4 test. Still, I might have missed something. Does it sound sane anyhow? [1] https://github.com/apache/ignite/pull/5354/files ср, 7 нояб. 2018 г. в 19:57, oignatenko <oignate...@gridgain.com>: > Hello, > > I created JIRA task for this move, with detailed explanation and > step-by-step subtasks, your comments are welcome: > > - https://issues.apache.org/jira/browse/IGNITE-10173 > > In brief, the plan is to gradually migrate the part of tests that still > uses > Junit 3 (hundreds if not thousands of those that depend on GridAbstractTest > and its subclasses) to newer version. The trick proposed to avoid doing all > this in one (big and risky) step is to introduce a Junit4-based "twin" of > GridAbstractTest (and respective twins of its subclasses) and use it to > gradually change tests to use that newer API instead. > > After above is over, Junit 3 and all its related stuff (including > GridAbstractTest) could be safely removed from project. > > regards, Oleg > > > > > -- > Sent from: http://apache-ignite-developers.2346864.n4.nabble.com/ > -- Best regards, Ivan Pavlukhin
