devdaily home | apple | java | perl | unix | directory | blog

What this is

This file is included in the DevDaily.com "Perl Source Code Warehouse" project. The intent of this project is to help you "Learn Perl by Example" TM.

Other links

The source code

#!./perl -w

# Tests for the coderef-in-@INC feature

BEGIN {
    chdir 't' if -d 't';
    @INC = qw(. ../lib);
}

use File::Spec;

require "test.pl";
plan(tests => 45);

my @tempfiles = ();

sub get_temp_fh {
    my $f = "DummyModule0000";
    1 while -e ++$f;
    push @tempfiles, $f;
    open my $fh, ">$f" or die "Can't create $f: $!";
    print $fh "package ".substr($_[0],0,-3).";\n1;\n";
    print $fh $_[1] if @_ > 1;
    close $fh or die "Couldn't close: $!";
    open $fh, $f or die "Can't open $f: $!";
    return $fh;
}

END { 1 while unlink @tempfiles }

sub fooinc {
    my ($self, $filename) = @_;
    if (substr($filename,0,3) eq 'Foo') {
	return get_temp_fh($filename);
    }
    else {
        return undef;
    }
}

push @INC, \&fooinc;

my $evalret = eval { require Bar; 1 };
ok( !$evalret,      'Trying non-magic package' );

$evalret = eval { require Foo; 1 };
die $@ if $@;
ok( $evalret,                      'require Foo; magic via code ref'  );
ok( exists $INC{'Foo.pm'},         '  %INC sees Foo.pm' );
is( ref $INC{'Foo.pm'}, 'CODE',    '  val Foo.pm is a coderef in %INC' );
is( $INC{'Foo.pm'}, \&fooinc,	   '  val Foo.pm is correct in %INC' );

$evalret = eval "use Foo1; 1;";
die $@ if $@;
ok( $evalret,                      'use Foo1' );
ok( exists $INC{'Foo1.pm'},        '  %INC sees Foo1.pm' );
is( ref $INC{'Foo1.pm'}, 'CODE',   '  val Foo1.pm is a coderef in %INC' );
is( $INC{'Foo1.pm'}, \&fooinc,     '  val Foo1.pm is correct in %INC' );

$evalret = eval { do 'Foo2.pl'; 1 };
die $@ if $@;
ok( $evalret,                      'do "Foo2.pl"' );
ok( exists $INC{'Foo2.pl'},        '  %INC sees Foo2.pl' );
is( ref $INC{'Foo2.pl'}, 'CODE',   '  val Foo2.pl is a coderef in %INC' );
is( $INC{'Foo2.pl'}, \&fooinc,     '  val Foo2.pl is correct in %INC' );

pop @INC;


sub fooinc2 {
    my ($self, $filename) = @_;
    if (substr($filename, 0, length($self->[1])) eq $self->[1]) {
	return get_temp_fh($filename);
    }
    else {
        return undef;
    }
}

my $arrayref = [ \&fooinc2, 'Bar' ];
push @INC, $arrayref;

$evalret = eval { require Foo; 1; };
die $@ if $@;
ok( $evalret,                     'Originally loaded packages preserved' );
$evalret = eval { require Foo3; 1; };
ok( !$evalret,                    'Original magic INC purged' );

$evalret = eval { require Bar; 1 };
die $@ if $@;
ok( $evalret,                     'require Bar; magic via array ref' );
ok( exists $INC{'Bar.pm'},        '  %INC sees Bar.pm' );
is( ref $INC{'Bar.pm'}, 'ARRAY',  '  val Bar.pm is an arrayref in %INC' );
is( $INC{'Bar.pm'}, $arrayref,    '  val Bar.pm is correct in %INC' );

ok( eval "use Bar1; 1;",          'use Bar1' );
ok( exists $INC{'Bar1.pm'},       '  %INC sees Bar1.pm' );
is( ref $INC{'Bar1.pm'}, 'ARRAY', '  val Bar1.pm is an arrayref in %INC' );
is( $INC{'Bar1.pm'}, $arrayref,   '  val Bar1.pm is correct in %INC' );

ok( eval { do 'Bar2.pl'; 1 },     'do "Bar2.pl"' );
ok( exists $INC{'Bar2.pl'},       '  %INC sees Bar2.pl' );
is( ref $INC{'Bar2.pl'}, 'ARRAY', '  val Bar2.pl is an arrayref in %INC' );
is( $INC{'Bar2.pl'}, $arrayref,   '  val Bar2.pl is correct in %INC' );

pop @INC;

sub FooLoader::INC {
    my ($self, $filename) = @_;
    if (substr($filename,0,4) eq 'Quux') {
	return get_temp_fh($filename);
    }
    else {
        return undef;
    }
}

my $href = bless( {}, 'FooLoader' );
push @INC, $href;

$evalret = eval { require Quux; 1 };
die $@ if $@;
ok( $evalret,                      'require Quux; magic via hash object' );
ok( exists $INC{'Quux.pm'},        '  %INC sees Quux.pm' );
is( ref $INC{'Quux.pm'}, 'FooLoader',
				   '  val Quux.pm is an object in %INC' );
is( $INC{'Quux.pm'}, $href,        '  val Quux.pm is correct in %INC' );

pop @INC;

my $aref = bless( [], 'FooLoader' );
push @INC, $aref;

$evalret = eval { require Quux1; 1 };
die $@ if $@;
ok( $evalret,                      'require Quux1; magic via array object' );
ok( exists $INC{'Quux1.pm'},       '  %INC sees Quux1.pm' );
is( ref $INC{'Quux1.pm'}, 'FooLoader',
				   '  val Quux1.pm is an object in %INC' );
is( $INC{'Quux1.pm'}, $aref,       '  val Quux1.pm  is correct in %INC' );

pop @INC;

my $sref = bless( \(my $x = 1), 'FooLoader' );
push @INC, $sref;

$evalret = eval { require Quux2; 1 };
die $@ if $@;
ok( $evalret,                      'require Quux2; magic via scalar object' );
ok( exists $INC{'Quux2.pm'},       '  %INC sees Quux2.pm' );
is( ref $INC{'Quux2.pm'}, 'FooLoader',
				   '  val Quux2.pm is an object in %INC' );
is( $INC{'Quux2.pm'}, $sref,       '  val Quux2.pm is correct in %INC' );

pop @INC;

push @INC, sub {
    my ($self, $filename) = @_;
    if (substr($filename,0,4) eq 'Toto') {
	$INC{$filename} = 'xyz';
	return get_temp_fh($filename);
    }
    else {
        return undef;
    }
};

$evalret = eval { require Toto; 1 };
die $@ if $@;
ok( $evalret,                      'require Toto; magic via anonymous code ref'  );
ok( exists $INC{'Toto.pm'},        '  %INC sees Toto.pm' );
ok( ! ref $INC{'Toto.pm'},         q/  val Toto.pm isn't a ref in %INC/ );
is( $INC{'Toto.pm'}, 'xyz',	   '  val Toto.pm is correct in %INC' );

pop @INC;

push @INC, sub {
    my ($self, $filename) = @_;
    if ($filename eq 'abc.pl') {
	return get_temp_fh($filename, qq(return "abc";\n));
    }
    else {
	return undef;
    }
};

$ret = "";
$ret ||= do 'abc.pl';
is( $ret, 'abc', 'do "abc.pl" sees return value' );

pop @INC;

my $filename = $^O eq 'MacOS' ? ':Foo:Foo.pm' : './Foo.pm';
{
    local @INC;
    @INC = sub { $filename = 'seen'; return undef; };
    eval { require $filename; };
    is( $filename, 'seen', 'the coderef sees fully-qualified pathnames' );
}




Copyright 1998-2008 Alvin Alexander
All Rights Reserved.
 
devdaily.com is based in louisville, kentucky, and this web site is hosted by godaddy.com