JUnit5 migration is currently mostly prepared. The rules are being migrated [1] and Hang and Qingsheng have migrated most tests in their branch afaik (Kudos to them!).
Using assertj would make migration easier as it's independent of the JUnit version. But the same can be said about hamcrest, albeit less expressive. I'm personally in favor of assertj (disclaimer I contributed to the project a bit). But I'm not sure if it's wise to change everything at once also from the perspective of less active contributors. We may alleviate that pain by providing good guides though. So maybe, we should also include a temporal dimension into the discussion. [1] https://github.com/apache/flink/pull/17556 On Fri, Nov 12, 2021 at 3:58 PM Till Rohrmann <trohrm...@apache.org> wrote: > Thanks for starting this discussion Francesco. I think there is a lot of > value in consistency because it makes it a lot easier to navigate and > contribute to the code base. The testing tools are definitely one important > aspect of consistency. > > It is a bit unfortunate that we have tests that follow different patterns. > This, however, is mainly due to organic growth. I think the community > started with Junit4, then we chose to use Hamcrest because of its better > expressiveness. Most recently, there was an effort started that aimed at > switching over to Junit5 [1, 2]. @Arvid Heise <ar...@apache.org> knows > more about the current status. > > Personally, I don't have a strong preference for which testing tools to > use. The important bit is that we agree as a community, then document the > choice and finally stick to it. So before starting to use assertj, we > should probably align with the folks working on the Junit5 effort first. > > [1] https://lists.apache.org/thread/jsjvc2cqb91pyh47d4p6olk3c1vxqm3w > [2] https://lists.apache.org/thread/d9y5tzcl8wpk6ozmf8575qfzww450jpk > > Cheers, > Till > > On Fri, Nov 12, 2021 at 3:41 PM David Anderson <dander...@apache.org> > wrote: > >> For what it's worth, I recently rewrote all of the tests in flink-training >> to use assertj, removing a mixture of junit4 assertions and hamcrest in >> the >> process. I chose assertj because I found it to be more expressive and made >> the tests more readable. >> >> +1 from me >> >> David >> >> On Fri, Nov 12, 2021 at 10:03 AM Francesco Guardiani < >> france...@ververica.com> wrote: >> >> > Hi all, >> > >> > I wonder If we have a convention of the testing tools (in particular >> > assertions) to use in our tests. If not, are modules free to decide on a >> > convention on their own? >> > >> > In case of table, we have a mixed bag of different assertions of all >> kinds, >> > sometimes mixed even in the same test: >> > >> > - Assertions from junit 4 >> > - Assertions from junit 5 >> > - Hamcrest >> > - Some custom assertions classes (e.g. RowDataHarnessAssertor) >> > - assert instructions >> > >> > The result is that most tests are very complicated to read and >> understand, >> > and we have a lot of copy pasted "assertion methods" all around our >> > codebase. >> > >> > For table in particular, I propose to introduce assertj [1] and develop >> a >> > couple of custom assertions [2] for the types we use most in our tests, >> > e.g. Row, RowData, DataType, LogicalType, etc... For example: >> > >> > assertFalse(row.isNullAt(1)); >> > assert row instanceof GenericRowData; >> > assertEquals(row.getField(1), >> TimestampData.ofEpochMillis(expectedMillis)); >> > >> > Could be: >> > >> > assertThat(row) >> > .getField(1, TimestampData.class) >> > .isEqualToEpochMillis(expectedMillis) >> > >> > We could have these in table-common so every part of the table stack can >> > benefit from it. Of course we can't take all our tests and convert them >> to >> > the new assertions, but as a policy we can enforce to use the new >> > assertions convention for every new test or for every test we modify in >> > future PRs. >> > >> > What's your opinion about it? Do you agree to have such kind of policy >> of >> > using the same assertions? If yes, do you like the idea of using >> assertj to >> > implement such policy? >> > >> > FG >> > >> > [1] A library for assertions https://assertj.github.io, already used by >> > the >> > pulsar connector >> > [2] >> https://assertj.github.io/doc/#assertj-core-custom-assertions-creation >> > -- >> > >> > Francesco Guardiani | Software Engineer >> > >> > france...@ververica.com >> > >> > >> > <https://www.ververica.com/> >> > >> > Follow us @VervericaData >> > >> > -- >> > >> > Join Flink Forward <https://flink-forward.org/> - The Apache Flink >> > Conference >> > >> > Stream Processing | Event Driven | Real Time >> > >> > -- >> > >> > Ververica GmbH | Invalidenstrasse 115, 10115 Berlin, Germany >> > >> > -- >> > >> > Ververica GmbH >> > >> > Registered at Amtsgericht Charlottenburg: HRB 158244 B >> > >> > Managing Directors: Karl Anton Wehner, Holger Temme, Yip Park Tung >> Jason, >> > Jinwei (Kevin) Zhang >> > >> >
