Follow mg_obj, which points to an SV.

[p5sagit/Devel-Size.git] / t / magic.t

diff --git a/t/magic.t b/t/magic.t
index d0f5b73..08d7eb0 100644 (file)
--- a/t/magic.t
+++ b/t/magic.t
@@ -1,7 +1,7 @@
 #!/usr/bin/perl -w
 
 use strict;
-use Test::More tests => 7;
+use Test::More tests => 11;
 use Devel::Size ':all';
 require Tie::Scalar;
 
@@ -31,3 +31,22 @@ require Tie::Scalar;
     cmp_ok($after_size, '>', $before_size, 'Still larger than initial size');
     cmp_ok($after_size, '<', $compiled_size, 'size decreases due to unmagic');
 }
+
+{
+    my $string = 'Perl Rules';
+    my $before_size = total_size($string);
+    cmp_ok($before_size, '>', length $string,
+          'Our string has a non-zero length');
+    tie $string, 'Tie::StdScalar';
+    my $after_size = total_size($string);
+    cmp_ok($after_size, '>', $before_size, 'size increases due to magic');
+    is($string, undef, 'No value yet');
+    # This is defineately cheating, in that we're poking inside the
+    # implementation of Tie::StdScalar, but if we just write to $string, the way
+    # magic works, the (nice long) value is first written to the regular scalar,
+    # then picked up by the magic. So it grows, which defeats the purpose of the
+    # test.
+    ${tied $string} = 'X' x 1024;
+    cmp_ok(total_size($string), '>', $after_size + 1024,
+          'the magic object is counted');
+}