Re: testing framework and package.el

[Stephen J. Turnbull]

Christian Ohler writes:
 >   On 13/10/10 4:41, Stephen J. Turnbull wrote:
 > > Christian Ohler writes:
 > >
 > >   >  As long as we don't touch a given test, we know that it's
 > >   >  compatible.  If we have to modify it to keep it passing, we know
 > >   >  that there was an incompatible change.
 > >
 > > You are forgetting new tests for old features.
 > 
 > I was referring to them as "tests written after the fact", sorry for not 
 > being clearer.
 > 
 > > These *must* be run against old versions to ensure that the
 > > current version of the feature is still compatible with the old
 > > one.
 > 
 > Yes; but this only needs to be done once per test.

That assumes that the test doesn't change, and that the test-writer
remembers to add/fix the test in old versions of Emacs.  If she
forgets, then it doesn't need to be done at all, you just have to live
with any divergences that *would* have been cuaght by the test.

 > The old version is not going to change.  This is assuming that
 > tests get merged into all branches where changes are made,
 > including bugfix branches.  I assume this is the part that you want
 > to avoid.

Yes, indeed.  I might do it, but I might forget.  I doubt very many
contributors would be willing to do so at all, unless reminded
aggressively.  But that sort of implies a "no commits without tests"
policy, and I don't think Emacs is ready for that.