Fix misleading errors for has_one through relations

1 files changed, 10 insertions, 2 deletions

diff --git a/activerecord/lib/active_record/associations/through_association.rb b/activerecord/lib/active_record/associations/through_association.rb
index 55ee9f04e0..d0ec3e8015 100644
--- a/activerecord/lib/active_record/associations/through_association.rb
+++ b/activerecord/lib/active_record/associations/through_association.rb
@@ -76,13 +76,21 @@ module ActiveRecord
 
         def ensure_mutable
           unless source_reflection.belongs_to?
-            raise HasManyThroughCantAssociateThroughHasOneOrManyReflection.new(owner, reflection)
+            if reflection.has_one?
+              raise HasOneThroughCantAssociateThroughHasOneOrManyReflection.new(owner, reflection)
+            else
+              raise HasManyThroughCantAssociateThroughHasOneOrManyReflection.new(owner, reflection)
+            end
           end
         end
 
         def ensure_not_nested
           if reflection.nested?
-            raise HasManyThroughNestedAssociationsAreReadonly.new(owner, reflection)
+            if reflection.has_one?
+              raise HasOneThroughNestedAssociationsAreReadonly.new(owner, reflection)
+            else
+              raise HasManyThroughNestedAssociationsAreReadonly.new(owner, reflection)
+            end
           end
         end