Test to make sure optional deps does not use any external modules

diff --git a/xt/optional_deps.t b/xt/optional_deps.t
index 9a59ac4..5e35930 100644 (file)
--- a/xt/optional_deps.t
+++ b/xt/optional_deps.t
@@ -5,9 +5,26 @@ no warnings qw/once/;
 use Test::More;
 use lib qw(t/lib);
 use Scalar::Util; # load before we break require()
+use Carp ();      # Carp is not used in the test, but we want to have it loaded for proper %INC comparison
+
+# a dummy test which lazy-loads more modules (so we can compare INC below)
+ok (1);
+
+# record contents of %INC - makes sure there are no extra deps slipping into
+# Opt::Dep.
+my $inc_before = [ keys %INC ];
+ok ( (! grep { $_ =~ m|DBIx/Class| } @$inc_before ), 'Nothing DBIC related is yet loaded');
 
 use_ok 'DBIx::Class::Optional::Dependencies';
 
+my $inc_after = [ keys %INC ];
+
+is_deeply (
+  [ sort @$inc_after],
+  [ sort (@$inc_before, 'DBIx/Class/Optional/Dependencies.pm') ],
+  'Nothing loaded other than DBIx::Class::OptDeps',
+);
+
 my $sqlt_dep = DBIx::Class::Optional::Dependencies->req_list_for ('deploy');
 is_deeply (
   [ keys %$sqlt_dep ],