[Pdx-pm] Pod::Coverage Weirdness with Class::Trait

Ovid publiustemp-pdxpm at yahoo.com
Wed Feb 15 07:46:57 PST 2006

--- Richard Clamp <richardc at unixbeard.net> wrote:

>              no warnings 'redefine';
>              eval qq{
>                  package $package;
>                  sub $method_label { $method(\@_) }
>              };
> To make Pod::Coverage happy that would be done as method injection,
> more like:
> {
>    no strict 'refs';
>    *{"$package\::$method_label"} = \&{$method};
> }
> But I only just met Class::Trait so I'm only speculating as to
> whether that's really equivalent.

As the current maintainer of Class::Trait, I'm embarrassed I forgot
about that.  Yeah, that's what could be causing the Pod::Coverage
behavior.  In fact, because traits are generally there for creating
public methods and not just for importing helper functions, I would
even argue that the Pod::Coverage behavior is correct.

As for the method injection in lieue of the eval, it fails in the case
of $self->SUPER::method(@_) because the trait methods get confused and
thing the class to redispatch to is the calling code (main:: in the
case of tests) instead of the proper SUPER class.

Because SUPER binds a bit too early for me, there's actually an
AUTOLOAD in Class::Trait::Base which traps and fixes this behavior, but
it relies on the eval().  Ugly, I know.  Here's the relevant code:

    # if someone is attempting a call to
    # SUPER, then we need to handle this.
    if ( my ($super_method) = $auto_load =~ /(SUPER::.*)/ ) {

        # get our arguemnts
        my ( $self, @args ) = @_;

        # lets get the intended method name
        $super_method = scalar( caller 1 ) . '::' . $super_method;
        return $self->$super_method(@args);

Now that I look at this, I wonder if searching the $self inheritance
tree would be better than checking caller?  I'm not sure.  I didn't
write this part of Class::Trait so I don't know the subtleties here.


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