Merge pull request #17374 from maurogeorge/scope-exception

Raises ArgumentError when try to define a scope without a callable

activerecord/CHANGELOG.md

@@ -1,3 +1,7 @@
+*   Raise `ArgumentError` when the body of a scope is not callable.
+
+    *Mauro George*
+
 *   Use type column first in multi-column indexes created with `add-reference`.
 
     *Derek Prior*

activerecord/lib/active_record/scoping/named.rb

@@ -139,6 +139,10 @@ module ActiveRecord
         #   Article.published.featured.latest_article
         #   Article.featured.titles
         def scope(name, body, &block)
+          unless body.respond_to?:call
+            raise ArgumentError, 'The scope body needs to be callable.'
+          end
+
           if dangerous_class_method?(name)
             raise ArgumentError, "You tried to define a scope named \"#{name}\" " \
               "on the model \"#{self.name}\", but Active Record already defined " \

activerecord/test/cases/scoping/named_scoping_test.rb

@@ -132,6 +132,13 @@ class NamedScopingTest < ActiveRecord::TestCase
     assert_equal Post.ranked_by_comments.limit_by(5), Post.top(5)
   end
 
+  def test_scopes_body_is_a_callable
+    e = assert_raises ArgumentError do
+      Class.new(Post).class_eval { scope :containing_the_letter_z, where("body LIKE '%z%'") }
+    end
+    assert_equal "The scope body needs to be callable.", e.message
+  end
+
   def test_active_records_have_scope_named__all__
     assert !Topic.all.empty?