Hi Stephan, Thanks for nice guide! I think we can upload this to the wiki or how to contribute documentation. This guide would be helpful for newcomers.
Regards, Chiwan Park > On Sep 17, 2015, at 9:33 PM, Stephan Ewen <se...@apache.org> wrote: > > Hi all! > > The build time of Flink with all tests is nearing 1h on Travis for the > shortest run. > It is good that we do excessive testing, there are many mechanisms that > need that. > > I have also seen that a lot of fixes that could be tested in a UnitTest > style are actually tested as a full Flink program (Integration test style) > > While these tests are always easier to write, they have two problems: > - The bring up the build time by about 5 secs per test > - They are often not as targeted to the problem as a UnitTest > > I would like to encourage everyone to keep this in mind and do Unit tests > in the cases where they are the preferred choice. Please also keep that in > mind when reviewing pull requests. > > For Example: > - API / TypeInformation changes can be very well tested without running > the program. Simply create the program and test the operator's type info. > - Custom functions can be very well tested in isolation > - Input/Output formats actually test well in UnitTests. > > Integration tests need to be used when verifying behavior across components > / layers, so keep using them when they need to be used. > > > Greetings, > Stephan
