source: trunk/essentials/dev-lang/perl/t/op/concat.t@ 3314

#!./perl

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

# This ok() function is specially written to avoid any concatenation.
my $test = 1;
sub ok {
    my($ok, $name) = @_;

    printf "%sok %d - %s\n", ($ok ? "" : "not "), $test, $name;

    printf "# Failed test at line %d\n", (caller)[2] unless $ok;

    $test++;
    return $ok;
}

print "1..29\n";

($a, $b, $c) = qw(foo bar);

ok("$a"     eq "foo",    "verifying assign");
ok("$a$b"   eq "foobar", "basic concatenation");
ok("$c$a$c" eq "foo",    "concatenate undef, fore and aft");

# Okay, so that wasn't very challenging.  Let's go Unicode.

{
    # bug id 20000819.004 

    $_ = $dx = "\x{10f2}";
    s/($dx)/$dx$1/;
    {
        ok($_ eq  "$dx$dx","bug id 20000819.004, back");
    }

    $_ = $dx = "\x{10f2}";
    s/($dx)/$1$dx/;
    {
        ok($_ eq  "$dx$dx","bug id 20000819.004, front");
    }

    $dx = "\x{10f2}";
    $_  = "\x{10f2}\x{10f2}";
    s/($dx)($dx)/$1$2/;
    {
        ok($_ eq  "$dx$dx","bug id 20000819.004, front and back");
    }
}

{
    # bug id 20000901.092
    # test that undef left and right of utf8 results in a valid string

    my $a;
    $a .= "\x{1ff}";
    ok($a eq  "\x{1ff}", "bug id 20000901.092, undef left");
    $a .= undef;
    ok($a eq  "\x{1ff}", "bug id 20000901.092, undef right");