Warn when Moose::Exporter is overwriting existing symbols.

diff --git a/lib/Moose/Exporter.pm b/lib/Moose/Exporter.pm
index 9d3b785..f33711f 100644 (file)
--- a/lib/Moose/Exporter.pm
+++ b/lib/Moose/Exporter.pm
@@ -9,7 +9,9 @@ $VERSION = eval $VERSION;
 our $AUTHORITY = 'cpan:STEVAN';
 
 use Class::MOP;
+use Carp qw(carp);
 use List::MoreUtils qw( first_index uniq );
+use Moose::Util;
 use Moose::Util::MetaRole;
 use Sub::Exporter 0.980;
 use Sub::Name qw(subname);
@@ -51,8 +53,30 @@ sub build_import_methods {
 
     my $exporter = Sub::Exporter::build_exporter(
         {
-            exports => $exports,
-            groups  => { default => [':all'] }
+            exports   => $exports,
+            groups    => { default => [':all'] },
+            installer => sub {
+                my ($arg, $to_export) = @_;
+                my $meta = Class::MOP::Package->initialize($arg->{into});
+
+                my @overwritten;
+
+                for (my $i = 0; $i < @{ $to_export }; $i += 2) {
+                    my $as = $to_export->[$i];
+                    push @overwritten, $as
+                        if $meta->has_package_symbol('&' . $as);
+                }
+
+                if (@overwritten) {
+                    local $Carp::CarpLevel = 2;
+                    carp $arg->{class}
+                        . " is overwriting symbol"
+                        . (@overwritten > 1 ? 's' : '') . " "
+                        . Moose::Util::english_list(map { join '::' => $arg->{into}, $_ } @overwritten);
+                }
+
+                goto &Sub::Exporter::default_installer;
+            },
         }
     );
 

diff --git a/t/050_metaclasses/012_moose_exporter.t b/t/050_metaclasses/012_moose_exporter.t
index 2809867..2c4fe79 100644 (file)
--- a/t/050_metaclasses/012_moose_exporter.t
+++ b/t/050_metaclasses/012_moose_exporter.t
@@ -393,10 +393,11 @@ BEGIN {
     package AlreadyHasImport;
 
     sub as_is1 { 42 }
+    sub with_caller1 { 23 }
 
     ::stderr_like(
-        sub { AllOptions->import('as_is1') },
-        qr/AllOptions is overwriting symbol as_is1 at ${\__FILE__}/,
+        sub { AllOptions->import('as_is1', 'with_caller1') },
+        qr/AllOptions is overwriting symbols AlreadyHasImport::as_is1 and AlreadyHasImport::with_caller1 at ${\__FILE__}/,
         'warning when overwriting existign symbols',
     );