An alternative approach could be to remove the randomness from the test by using a predefined random seed and test the overloaded variants that accept a second java.util.Random argument. This will superficially reduce the test's coverage, but it does have a reliability advantage, IMHO (as seen in Otto's original email - these tests do fail occasionally).
I posted https://github.com/apache/commons-lang/pull/317 to show this approach On Wed, Feb 28, 2018 at 12:00 AM, Gary Gregory <garydgreg...@gmail.com> wrote: > Of course... but how would test then? Shuffle N times and accept a % of > non-shuffles? > > Gary > > On Tue, Feb 27, 2018, 13:18 Allon Mureinik <murei...@gmail.com> wrote: > > > There will still be a chance, however infinitesimal, of a failure. :-) > > > > > > On Tue, Feb 27, 2018 at 9:02 PM, Gary Gregory <garydgreg...@gmail.com> > > wrote: > > > > > Why not make the array 1000 items long? > > > > > > Gary > > > > > > On Tue, Feb 27, 2018 at 10:31 AM, Allon Mureinik <murei...@gmail.com> > > > wrote: > > > > > > > All the ArrayUtilsTest#testShuffleXYZ tests take an array, shuffle > it, > > > and > > > > assert that the result isn't equal to the original array. > > > > This is usually true, but there's a small chance that the shuffled > > array > > > > will be equal to the original array, and thus the test will fail. > This > > > > chance is higher for the testShuffleBoolean case where the array > > contains > > > > ten elements, but only two distinct values (true and false). > > > > > > > > I've sent a PR to remove these problematic assertions, let's see what > > the > > > > maintainers think of it: > > > > https://github.com/apache/commons-lang/pull/316 > > > > > > > > > > > > On Tue, Feb 27, 2018 at 6:59 PM, Otto Fowler < > ottobackwa...@gmail.com> > > > > wrote: > > > > > > > > > Note, this does pass in my personal travis: > > > > > https://travis-ci.org/ottobackwards/commons-lang/builds/346806991 > > > > > > > > > > > > > > > On February 27, 2018 at 11:58:24, Otto Fowler ( > > ottobackwa...@gmail.com > > > ) > > > > > wrote: > > > > > > > > > > My PR is currently failing for java 9 on this test. Anyone have > any > > > idea > > > > > why? > > > > > > > > > > [INFO] Running org.apache.commons.lang3.ArrayUtilsTest > > > > > [ERROR] Tests run: 307, Failures: 1, Errors: 0, Skipped: 0, Time > > > elapsed: > > > > > 0.114 s <<< FAILURE! - in org.apache.commons.lang3.ArrayUtilsTest > > > > > [ERROR] testShuffleBoolean(org.apache. > commons.lang3.ArrayUtilsTest) > > > Time > > > > > elapsed: 0.008 s <<< FAILURE! > > > > > java.lang.AssertionError > > > > > at > > > > > org.apache.commons.lang3.ArrayUtilsTest.testShuffleBoolean( > > > > > ArrayUtilsTest.java:5023) > > > > > > > > > > > > > > >
