>From http://use.perl.org/~Ovid/journal/39193
The latest developer release of Test::More allows subtests. Subtests are great
in that they solve a lot of
problems in advanced Perl testing, but they have required a change in
Test::Builder. Previously you could do stuff like this:
package Test::StringReverse;
use base 'Test::Builder::Module';
our @EXPORT = qw(is_reversed);
my $BUILDER = Test::Builder->new;
sub is_reversed ($$;$) {
my ( $have, $want, $name ) = @_;
my $passed = $want eq scalar reverse $name;
$BUILDER->ok($passed, $name);
$BUILDER->diag(<<" END_DIAG") if not $passed;
have: $have
want: $want
END_DIAG
return $passed;
}
1;
And you've have a simple (untested;) test for whether or not strings are
reversed. The reason that worked is that Test::Builder->new used to return a
singleton. This is no longer true. If someone uses
your test library in a subtest, the above code would break. Instead,
you want to do this:
sub is_reversed ($$;$) {
my ( $have, $want, $name ) = @_;
my $passed = $want eq scalar reverse $name;
my $builder = __PACKAGE__->builder;
$builder->ok($passed, $name);
$builder->diag(<<" END_DIAG") if not $passed;
have: $have
want: $want
END_DIAG
return $passed;
}
It's a minor change, it's completely backwards-compatible and it supports
subtests.
Cheers,
Ovid
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