[Perlunit-users] assert_isa, assert_can: accept class names?

[Matthew A. <mc...@us...>]

I've just added to CVS Marek's patch from the RT bug at
 http://rt.cpan.org/NoAuth/Bug.html?id=4613

Changes will be visible at
  http://cvs.sourceforge.net/viewcvs.py/perlunit/src/Test-Unit/lib/Test/Unit/Assert.pm
  http://cvs.sourceforge.net/viewcvs.py/perlunit/src/Test-Unit/t/tlib/AssertTest.pm
once the public repository has updated.


The patch provides new assertions like this,

    my $object = Horse->new("Dobbin");
    $self->assert_isa('Horse', $object);
    $self->assert_can('gallop', $object);

and what I'm wondering is whether folks expect these to pass
classnames in addition to instances of the classes,

    $self->assert_isa('Horse', 'Horse::Shire');
    $self->assert_can('gallop', 'Horse');

when @Horse::Shire::ISA = ('Horse') .


There are several options,

 1) accept classnames as well as objects, to match the behaviour of
    UNIVERSAL::isa and UNIVERSAL::can

 2) don't accept classnames because that's less likely to be useful in
    testing - this is what Marek's original code does

 3) same as 2) but change the names to assert_objisa and assert_objcan

For now I've left the code doing 2) but the installation tests require
1), so this will need resolving one way or another before the next
release.  It seemed best to ask the users what they expect the code to
do...


Other questions that might arise later are

 do we need assert_not_isa and assert_not_can?  or some way to make
 composite assertions, that would make this easier?

 do we need to break Test::Unit::Assert or its POD down into smaller
 pieces to make it less scary?

Suggestions welcome.


Matthew  #8-)