better error when no predicate for required attribute

diff --git a/lib/Reaction/InterfaceModel/Action.pm b/lib/Reaction/InterfaceModel/Action.pm
index 70eb0d1..0074b02 100644 (file)
--- a/lib/Reaction/InterfaceModel/Action.pm
+++ b/lib/Reaction/InterfaceModel/Action.pm
@@ -33,6 +33,8 @@ sub can_apply {
   foreach my $attr ($self->parameter_attributes) {
     my $predicate = $attr->get_predicate_method;
     if ($self->attribute_is_required($attr)) {
+      confess "No predicate for required attribute ${\$attr->name} for ${self}"
+        unless $predicate;
       return 0 unless $self->$predicate;
     }
     if ($attr->has_valid_values) {