On Tuesday 09 September 2003 15:29, Tony Bowden wrote:
> On Tue, Sep 09, 2003 at 01:25:22PM +0100, Adrian Howard wrote:
> > >1) ok $str1 eq $str2;
> > >2) is $str1, $str2;
> > >3) is_deeply [$str1], [$str2];
> > >4) is_deeply $str1, $str2;
> > All should pass as far as I am concerned.
I agree. There is no difference between them except the class into which they
are blessed and is_deeply is supposed to ignore classes.
> my $str1 = MyString->new("foo", "bar");
> my $str2 = MyOtherString->new("foo", "baz");
Now they _do_ differ by more than just class and it should be a fail, although
I must admit that even with the current is_deeply it will be a pass. I
consider that a bug and it's something I avoided in Test::Deep by using
Scalar::Util::refaddr, I just never backported that to Test::More.
The reason I want it to fail is because if I pass these objects (and they are
definitely objects, they're only strings if you squint) into some other
function which calls a method on them then "bar" vs "baz" might be a very
crucial difference. Or if I pass them to a function that behaves differently
for strings and objects, I'll get the object behaviour, not the string
behaviour.
For me, it comes down to 2 things, utility and the total pain in the backside
that it would be to even get close to implementing what's being asked for.
<utility>
Which is more useful?
Scenario A:
"Mr deeply please check that datastructure and tell me if it's an array of a
type 5 widgets"
"I checked and it's exactly what you asked for no way could it be anything
different"
Scenario B:
"Mr deeply please check that datastructure and tell me if it's an array of a
type 5 widgets"
"Well, some of them definitely were and some of them had labels on them that
said they were so I didn't bother checking those"
"which ones has labels?"
"none of them, all of them, some of them, I can't remember. Relax it's only
testing. Look at them yourself if you want to be sure"
</utility>
Here's my pop quiz what is the result of this
package Counter;
use overload '""' => \&get;
sub new
{
my $val = 1;
return bless \$val, shift;
}
sub get
{
my $self = shift;
return ${$self}++;
}
my $counter = Couner->new;
is_deeply(
{ a => $counter, b => $counter},
{ a => 1, $b => 2}
);
for bonus points, what will be the puzzling diagnostic message?
<pain>
We need changes in _deep_check, in diagnostics, we also need to forget about
handling circular structures and we need to document it properly so that this
doesn't happen again.
</pain>
Another quiz, given that is_deeply is supposed to ignore blessings on
references, see
http://www.mail-archive.com/[EMAIL PROTECTED]/msg01679.html
how about this
sub three_tests
{
my ($a, $b) = @_;
is_deeply($a, $b);
bless $a, "wibble";
is_deeply($a, $b);
bless $a, "MyString";
is_deeply($a, $b);
}
three_tests({value => "cat"}, {value => "cat"});
three_tests({value => "cat"}, "cat");
Finally did anyone's intuitive knowledge of is_deeply include this
possibility?
is_deeply($a, $b)
OK
is_deeply($b, $c)
OK
is_deeply($a, $c)
NOT OK
or this
my $a = bless [$something], "APackage";
my $b = fn();
if (is_deeply($a, $b))
{
isa_ok($b->[0], "anotherPackage");
}
Not an ARRAY reference at line 5.
The outcome of a good test should indicate 1 thing and 1 thing only. It should
not mean A was true or B was true because then you have to test specifically
for A or for B in which case why bother with the original test,
F
