Throw a sensible error when a malformed 'as'-spec is supplied

diff --git a/Changes b/Changes
index 3139ec3..275273f 100644 (file)
--- a/Changes
+++ b/Changes
@@ -4,6 +4,7 @@ Revision history for DBIx::Class
         - Fix tests for DBD::SQLite >= 1.34.
         - Fix the find() condition heuristics being invoked even when the
           call defaults to 'primary' (i.e. when invoked with bare values)
+        - Throw much clearer error on incorrect inflation spec
 
     * Misc
         - No longer depend on Variable::Magic now that a pure-perl

diff --git a/lib/DBIx/Class/Row.pm b/lib/DBIx/Class/Row.pm
index 4eaa431..60c854b 100644 (file)
--- a/lib/DBIx/Class/Row.pm
+++ b/lib/DBIx/Class/Row.pm
@@ -1139,23 +1139,38 @@ sub inflate_result {
 
   foreach my $pre (keys %{$prefetch||{}}) {
 
-    my $pre_source = $source->related_source($pre)
-      or $class->throw_exception("Can't prefetch non-existent relationship ${pre}");
-
-    my $accessor = $source->relationship_info($pre)->{attrs}{accessor}
-      or $class->throw_exception("No accessor for prefetched $pre");
-
-    my @pre_vals;
+    my (@pre_vals, $is_multi);
     if (ref $prefetch->{$pre}[0] eq 'ARRAY') {
+      $is_multi = 1;
       @pre_vals = @{$prefetch->{$pre}};
     }
-    elsif ($accessor eq 'multi') {
-      $class->throw_exception("Implicit prefetch (via select/columns) not supported with accessor 'multi'");
-    }
     else {
       @pre_vals = $prefetch->{$pre};
     }
 
+    my $pre_source = try {
+      $source->related_source($pre)
+    }
+    catch {
+      $class->throw_exception(sprintf
+
+        "Can't inflate manual prefetch into non-existent relationship '%s' from '%s', "
+      . "check the inflation specification (columns/as) ending in '%s.%s'.",
+
+        $pre,
+        $source->source_name,
+        $pre,
+        (keys %{$pre_vals[0][0]})[0] || 'something.something...',
+      );
+    };
+
+    my $accessor = $source->relationship_info($pre)->{attrs}{accessor}
+      or $class->throw_exception("No accessor type declared for prefetched $pre");
+
+    if (! $is_multi and $accessor eq 'multi') {
+      $class->throw_exception("Manual prefetch (via select/columns) not supported with accessor 'multi'");
+    }
+
     my @pre_objects;
     for my $me_pref (@pre_vals) {
 

diff --git a/t/prefetch/incomplete.t b/t/prefetch/incomplete.t
index a93e693..8682ba7 100644 (file)
--- a/t/prefetch/incomplete.t
+++ b/t/prefetch/incomplete.t
@@ -6,8 +6,6 @@ use Test::Exception;
 use lib qw(t/lib);
 use DBICTest;
 
-plan tests => 9;
-
 my $schema = DBICTest->init_schema();
 
 lives_ok(sub {
@@ -51,3 +49,14 @@ lives_ok(sub {
   is ($cd->artist->name, 'Random Boy Band', 'Artist object has correct name');
 
 }, 'implicit keyless prefetch works');
+
+# sane error
+throws_ok(
+  sub {
+    $schema->resultset('Track')->search({}, { join => { cd => 'artist' }, '+columns' => 'artist.name' } )->next;
+  },
+  qr|\QCan't inflate manual prefetch into non-existent relationship 'artist' from 'Track', check the inflation specification (columns/as) ending in 'artist.name'|,
+  'Sensible error message on mis-specified "as"',
+);
+
+done_testing;