`validates_acceptance_of` shouldn't require a database connection

The implementation of `attribute_method?` on Active Record requires
establishing a database connection and querying the schema. As a general
rule, we don't want to require database connections for any class macro,
as the class should be able to be loaded without a database (e.g. for
things like compiling assets).

Instead of eagerly defining these methods, we do it lazily the first
time they are accessed via `method_missing`. This should not cause any
performance hits, as it will only hit `method_missing` once for the
entire class.

1 files changed, 11 insertions, 0 deletions

diff --git a/activerecord/test/cases/validations_test.rb b/activerecord/test/cases/validations_test.rb
index a429d06aad..d04f4f7ce7 100644
--- a/activerecord/test/cases/validations_test.rb
+++ b/activerecord/test/cases/validations_test.rb
@@ -168,4 +168,15 @@ class ValidationsTest < ActiveRecord::TestCase
   ensure
     Topic.reset_column_information
   end
+
+  def test_acceptance_validator_doesnt_require_db_connection
+    klass = Class.new(ActiveRecord::Base) do
+      self.table_name = 'posts'
+    end
+    klass.reset_column_information
+
+    assert_no_queries do
+      klass.validates_acceptance_of(:foo)
+    end
+  end
 end