"Can't call method "category" without a package or object reference at" in perl

Question

I can't seem to figure this out, and I couldn't find anything online. So here is my code:

Type.pm

use constant {
UNABLE_TO_PING_SWITCH_ERROR => {
         category => 'Connection Error',
         template => "Could not ping switch %s in %s seconds.",
         context => [ qw(switch_ip  timeout) ],
         tt => {template => 'disabled'},
         fatal => 1,
         wiki_page => 'www.error-fix.com/',
     },
};

Error.pm The new method outputs the error message in the format shown in stringify

# Method for creating error message
  sub new {
      my ( $class, $error, %args ) = @_;
      # Initialize error with data
      my $self = $error;
      # If the error contains context parameters... Insert parameters into string template
      if(%args) {
          foreach my $key (@{ $self->{context} } ) {
              # And take the ones we need
              $self->{args}->{$key} = $args{$key};
          }
          my @template_args = map { $self->{args}->{$_} } @{ $self->{context} };
          # map/insert arguments into context hash and insert into string template
          $self->{message} = sprintf ($self->{template}, @template_args);
          $self->stringify;
          }
          return bless $self, $class;
      }
      else { return bless $self, $class; }
  }

stringify {
    my ($self) = @_;
    return sprintf("%s : %s\nMore info: %s", $self->category, $self->message, $self->wiki_page);
}

This is the error I am receiving.

#   Failed test 'Return the correct message'
    #   at t/67_Error.t line 47.
    #          got: undef
    #     expected: 'Could not ping switch 192.192.0.0 in 30 seconds.'
Can't call method "category" without a package or object reference at Error.pm line 77.

Line 77 is the return statement inside stringify.

If you need any more info or code let me know.

Attempt solution (sof far)

 sub new {
    my ( $class, $error, %args ) = @_;
    # Initialize error with data
    my $self = $error;
    # If the error contains context parameters... Insert parameters into string template
        if($self eq 'HASH' && %args) {
            bless $self, $class;
            foreach my $key (@{ $self->{context} } ) {
                 # bless $self, $class;
                 # And take the ones we need
                 $self->{args}->{$key} = $args{$key};
            }
            my @template_args = map { $self->{args}->{$_} } @{ $self->{context} };
            # map/insert arguments into context hash and insert into string template
            $self->{message} = sprintf ($self->{template}, @template_args);
            my $output = _stringify($self->category, $self->message, $self->wiki_page);
            bless $output, $class;
            return $output;
            }
            else { return bless $self, $class; }
   }

Test Code : t/67_Error.t

#!/usr/bin/env perl

use lib ('./t/lib');
use strict;
no strict 'refs';
use warnings;

use ASC::Builder::Error;
use ASC::Builder::Error::Type;
use ASC::Builder::Error::Type 'code';
use Test::More;
use Test::Exception;
use LWP::Simple 'head'; # Used to test if wiki link is giving a response

subtest 'Functionality of Error' => sub {

    my $example_error = {
        category => 'Connection Error',
        template => 'Could not ping switch %s in %s seconds.',
        context => [ qw(switch_ip  timeout) ],
        tt => {template => 'disabled'},
        fatal => 1,
        wiki_page => 'http://www.error-fix.com',
    };
    # Correct case
    {
        my $error = ASC::Builder::Error->new( $example_error, timeout => 30, switch_ip => '192.192.0.0' );

        isa_ok ($error, 'ASC::Builder::Error');

        can_ok ($error, 'category');
        is ($error->category(), 'Connection Error', 'Return the correct category');

        can_ok ($error, 'template');
        is ($error->template(), 'Could not ping switch %s in %s seconds.', 'Return the correct category');

        can_ok ($error, 'tt');
        is ($error->tt(), 'disabled', 'Return the correct tt template');

        can_ok ($error, 'context');
        is_deeply($error->context(), ['switch_ip', 'timeout'], 'Return the correct context params');

        can_ok ($error, 'is_fatal');
        ok($error->is_fatal(), 'Return the correct value');

        can_ok ($error, 'message');
        is ($error->message(), 'Could not ping switch 192.192.0.0 in 30 seconds.', 'Return the correct message');
        can_ok ($error, 'stringify');
        is ($error->stringify(), "Connection Error : Could not ping switch 192.192.0.0 in 30 seconds.\nMore info: http://www.error-fix.com", 'stringify creates the correct message');

};

    # Too many arguments (this is okay)
    lives_ok( sub { ASC::Builder::Error->new($example_error, timeout => 1, switch_ip => 2, extra => 3 ) }, 'Creating with too many arguments lives. (allows for additional context          string to be added in the code)' );
    };

    subtest 'Correctness of Type.pm' => sub {

# These test cases contain all the errors from Type.pm
    my @test_cases = (
       {
            name => 'UNABLE_TO_PING_SWITCH_ERROR',
            args => {
                switch_ip => '192.192.0.0',
                timeout => 30,
            },
            message => 'Could not ping switch 192.192.0.0 in 30 seconds.',
        },
    );


    foreach my $t (@test_cases) {
        subtest $t->{name} => sub {
            no strict 'refs'; # Because we need to use variable to get to a constant
            ASC::Builder::Error::Type->import($t->{name});

            # Create the Error object from the test data
            # Will also fail if the name was not exported by Type.pm
            my $error;
            lives_ok( sub { $error = ASC::Builder::Error->new( &{ $t->{name} },%{ $t->{args} }) }, 'Error can be created');

            # See if it has the right values
            is ($error->message, $t->{message}, 'Error message is correct');

            # Using LWP::Simple to check if the wiki page link is not broken
            #ok head($error->wiki_page); #CANT'T GET THIS TEST TO WORK

        }
    }
};
done_testing;

UPDATE: Message method:

It is just a getter.

 sub message {
        return shift->{message};
 }

Answer 1

return sprintf("%s : %s\nMore info: %s", $self->category, $self->message, $self->wiki_page);

Here the code looks like you're invoking methods called category, message and wiki_page on $self. You should put them in braces if they are actually hash keys.