> 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.
That is fine, I'm sorry if my mail felt like a rant :) > 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. As Arvid pointed out, using assertj might help the people working on the junit5 effort as well, since assertj works seamlessly with junit4, junit5 and even other java testing frameworks. > 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. This is why I'm proposing a convention and not a rewrite of all the tests at once, that's unfeasible. As you sad, we can provide guides, like in our contribution guides, explaining our assertion convention, that is use assertj or whatever other library we want to use and how. So then we can ask contributors to use such assertion convention when they PR new tests or when they modify existing ones. Something like that: https://github.com/apache/flink-web/commit/87c572ccd4e0ae48eeff3eb15ad9847d302e659d On Fri, Nov 12, 2021 at 5:07 PM Arvid Heise <ar...@apache.org> wrote: > 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 > >> > > >> > > >
