Hi.
On Wed, 28 Feb 2018 08:49:42 +0200, Allon Mureinik wrote:
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 do not seen the occasional failures as a problem if one is aware
that they can happen due to the "random" nature of the algorithm.[1]
Letting the seed vary (as in the application world) can reveal
unexpected behaviour.[2]
Gilles
[1] See here for example:
https://travis-ci.org/apache/commons-rng/builds/345961304
[2] See here for example:
https://issues.apache.org/jira/projects/MATH/issues/MATH-1361
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)
> > > >
> > >
> >
>
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