Delay croaking until use. Fixes RT #119534.

This is to maintain compatibility with modules that declare types but
never use them. In 0.49, this could cause an exception if
Sub::Defer::undefer_all was called.

Author: oschwald

lib/MooseX/Types.pm

@@ -491,9 +491,11 @@ sub coercion_export_generator {
         my ($value) = @_;
 
         # we need a type object
-        my $tobj = find_type_constraint($full) or croak $undef_msg;
+        my $tobj = find_type_constraint($full);
 
         return sub {
+            croak $undef_msg unless $tobj;
+
             my $return = $tobj->coerce($_[0]);
 
             # non-successful coercion returns false
@@ -517,11 +519,15 @@ sub check_export_generator {
         my ($value) = @_;
 
         # we need a type object
-        my $tobj = find_type_constraint($full) or croak $undef_msg;
+        my $tobj = find_type_constraint($full);
 
         # This method will actually compile an inlined sub if possible. If
         # not, it will return something like sub { $tobj->check($_[0]) }
-        return $tobj->_compiled_type_constraint;
+        #
+        # If $tobj is undef, we delay the croaking until the check is
+        # actually used for backward compatibility reasons. See
+        # RT #119534.
+        return $tobj ? $tobj->_compiled_type_constraint : sub { croak $undef_msg};
     }
 }
 

t/27-sub-defer.t

@@ -25,4 +25,17 @@ unlike(
     'is_Int sub is now undeferred'
 );
 
+{
+    package MyTypes;
+
+    use MooseX::Types -declare => ['Unused'];
+
+}
+
+is(
+    exception { undefer_all() },
+    undef,
+    'Sub::Defer::undefer_all does not throw an exception with unused type declaration'
+);
+
 done_testing();