new page added to wiki: https://github.com/sympy/sympy/wiki/Closing-an-Issue
On Tuesday, September 2, 2014 9:26:59 PM UTC-5, Chris Smith wrote: > > At https://github.com/sympy/sympy/pull/7945 discussion involving a change > that I made to a test that was added in response to issue 6533 has arisen. > In that issue a particular expression (which is slow to compute) raised an > assertion error, identifying that a change needed to be made in the code. > The code was fixed and that original slow expression and 2 others were > added as tests. > > I noticed this issue while waiting for a local test to run. Specifically, > I noticed that the slow test was taking about 2 minutes. I went back in > history to where the change was made, backed up to the previous commit, and > experimented with simpler expressions (similar to the one identified in the > issue) that gave the same error. I replaced the original tests with that > expression. > > The question that has come up is whether the original error-producing > expression needs to appear in the test suite. I think not and offer the > following guide for adding tests for code modified after a problem has been > identified: > > 1) use the original failing expression unless a much simpler expression > will exhibit the same failure or a similar expression will run much faster; > if the original expression runs quickly and is not too complicated, it is > not necessary to spend much time trying to find something simpler. > 2) add any additional tests needed to make sure that all the code added is > covered. > > The reason for not using the original expression is that in debugging a > problem one often finds what the key failing issue is and can pinpoint that > portion of code with a simpler test. > > I just happened across this issue and went back to the commit before the > commit that fixed the issue (0fa7b9730e56759e5f4bc3752143f5) and found a > simpler expression that failed in the same way as the original expression > and covered the few lines that were added in the fix. On my computer it > cuts about 2 minutes off the suite test time. I would like to make this > change in PR https://github.com/sympy/sympy/pull/7945 . It has been > requested that somebody else confirm or reject my proposal. > -- You received this message because you are subscribed to the Google Groups "sympy" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/sympy. To view this discussion on the web visit https://groups.google.com/d/msgid/sympy/63d48bce-0d23-41e4-a43e-9317a41aa074%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
