die with a helpful error message if $TYPE_MAP{$isa}->() returned something useless

diff --git a/Changes b/Changes
index a2f8e03..a0f1dc9 100644 (file)
--- a/Changes
+++ b/Changes
@@ -1,3 +1,4 @@
+  - throw a useful exception when typemap doesn't return a value
   - avoid localising @_ when not required for Sub::Quote
   - successfully inflate a metaclass for attributeless classes (RT#86415)
   - fix false default values used with non-lazy accessors

diff --git a/lib/Moo/HandleMoose.pm b/lib/Moo/HandleMoose.pm
index 3bcb725..15ab89e 100644 (file)
--- a/lib/Moo/HandleMoose.pm
+++ b/lib/Moo/HandleMoose.pm
@@ -56,7 +56,7 @@ sub inject_real_metaclass_for {
   my ($name) = @_;
   our %DID_INJECT;
   return Class::MOP::get_metaclass_by_name($name) if $DID_INJECT{$name};
-  require Moose; require Moo; require Moo::Role;
+  require Moose; require Moo; require Moo::Role; require Scalar::Util;
   Class::MOP::remove_metaclass_by_name($name);
   my ($am_role, $meta, $attr_specs, $attr_order) = do {
     if (my $info = $Moo::Role::INFO{$name}) {
@@ -109,6 +109,8 @@ sub inject_real_metaclass_for {
         my $tc = $spec{isa} = do {
           if (my $mapped = $TYPE_MAP{$isa}) {
             my $type = $mapped->();
+            Scalar::Util::blessed($type) && $type->isa("Moose::Meta::TypeConstraint")
+              or die "error inflating attribute '$name' for package '$_[0]': \$TYPE_MAP{$isa} did not return a valid type constraint'";
             $coerce ? $type->create_child_type(name => $type->name) : $type;
           } else {
             Moose::Meta::TypeConstraint->new(

diff --git a/xt/moox-types.t b/xt/moox-types.t
index 3f3eef5..59edbe4 100644 (file)
--- a/xt/moox-types.t
+++ b/xt/moox-types.t
@@ -39,4 +39,20 @@ is(
   'External (MooseX::Types type) ok'
 );
 
+local $@;
+eval q {
+  package Fooble;
+  use Moo;
+  my $isa = sub { 1 };
+  $Moo::HandleMoose::TYPE_MAP{$isa} = sub { $isa };
+  has barble => (is => "ro", isa => $isa);
+  __PACKAGE__->meta->get_attribute("barble");
+};
+
+like(
+  $@,
+  qr{^error inflating attribute 'barble' for package 'Fooble': \$TYPE_MAP\{CODE\(\w+?\)\} did not return a valid type constraint},
+  'error message for incorrect type constraint inflation',
+);
+
 done_testing;