1 files changed, 9 insertions, 0 deletions
diff --git a/activerecord/test/cases/connection_adapters/abstract_adapter_test.rb b/activerecord/test/cases/connection_adapters/abstract_adapter_test.rb
index 1fd64dd0af..eb2fe5639b 100644
--- a/activerecord/test/cases/connection_adapters/abstract_adapter_test.rb
+++ b/activerecord/test/cases/connection_adapters/abstract_adapter_test.rb
@@ -2,6 +2,15 @@ require "cases/helper"
 
 module ActiveRecord
   module ConnectionAdapters
+    class ConnectionPool
+      def insert_connection_for_test!(c)
+        synchronize do
+          @connections << c
+          @available.add c
+        end
+      end
+    end
+
     class AbstractAdapterTest < ActiveRecord::TestCase
       attr_reader :adapter