#!./perl -w
#
#  Copyright 2005, Adam Kennedy.
#
#  You may redistribute only under the same terms as Perl 5, as specified
#  in the README file that comes with the distribution.
#

# Tests freezing/thawing structures containing Singleton objects,
# which should see both structs pointing to the same object.

use Test::More tests => 11;
use Storable ();

# Get the singleton
my $object = My::Singleton->new;
isa_ok( $object, 'My::Singleton' );

# Confirm (for the record) that the class is actually a Singleton
my $object2 = My::Singleton->new;
isa_ok( $object2, 'My::Singleton' );
is( $object, $object2, 'Class is a singleton' );

############
# Main Tests

my $struct = \@( 1, $object, 3 );

# Freeze the struct
my $frozen = Storable::freeze( $struct );
ok( (defined($frozen) and ! ref($frozen) and length($frozen)), 'freeze returns a string' );

# Thaw the struct
my $thawed = Storable::thaw( $frozen );

# Now it should look exactly like the original
is_deeply( $struct, $thawed, 'Struct superficially looks like the original' );

# ... EXCEPT that the Singleton should be the same instance of the object
is( $struct->[1], $thawed->[1], 'Singleton thaws correctly' );

# We can also test this empirically
$struct->[1]->{+value} = 'Goodbye cruel world!';
is_deeply( $struct, $thawed, 'Empiric testing corfirms correct behaviour' );

# End Tests
###########

package My::Singleton;

my $SINGLETON = undef;

sub new {
	$SINGLETON or
	$SINGLETON = bless \%( value => 'Hello World!' ), @_[0];
}

sub STORABLE_freeze {
	my $self = shift;

	# We don't actually need to return anything, but provide a null string
	# to avoid the null-list-return behaviour.
	return  @('foo');
}

sub STORABLE_attach($class, $clone, $string) {
	Test::More::ok( ! ref $class, 'STORABLE_attach passed class, and not an object' );
	Test::More::is( $class, 'My::Singleton', 'STORABLE_attach is passed the correct class name' );
	Test::More::is( $clone, 0, 'We are not in a dclone' );
	Test::More::is( $string, 'foo', 'STORABLE_attach gets the string back' );

	# Get the Singleton object and return it
	return $class->new;
}