1 files changed, 56 insertions, 0 deletions
diff --git a/activerecord/test/cases/adapters/postgresql/postgresql_adapter_test.rb b/activerecord/test/cases/adapters/postgresql/postgresql_adapter_test.rb
index cbb6cd42b5..34b4fc344b 100644
--- a/activerecord/test/cases/adapters/postgresql/postgresql_adapter_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/postgresql_adapter_test.rb
@@ -376,6 +376,62 @@ module ActiveRecord
         end
       end
 
+      def test_errors_when_an_insert_query_is_called_while_preventing_writes
+        with_example_table do
+          assert_raises(ActiveRecord::ReadOnlyError) do
+            @connection.while_preventing_writes do
+              @connection.execute("INSERT INTO ex (data) VALUES ('138853948594')")
+            end
+          end
+        end
+      end
+
+      def test_errors_when_an_update_query_is_called_while_preventing_writes
+        with_example_table do
+          @connection.execute("INSERT INTO ex (data) VALUES ('138853948594')")
+
+          assert_raises(ActiveRecord::ReadOnlyError) do
+            @connection.while_preventing_writes do
+              @connection.execute("UPDATE ex SET data = '9989' WHERE data = '138853948594'")
+            end
+          end
+        end
+      end
+
+      def test_errors_when_a_delete_query_is_called_while_preventing_writes
+        with_example_table do
+          @connection.execute("INSERT INTO ex (data) VALUES ('138853948594')")
+
+          assert_raises(ActiveRecord::ReadOnlyError) do
+            @connection.while_preventing_writes do
+              @connection.execute("DELETE FROM ex where data = '138853948594'")
+            end
+          end
+        end
+      end
+
+      def test_doesnt_error_when_a_select_query_is_called_while_preventing_writes
+        with_example_table do
+          @connection.execute("INSERT INTO ex (data) VALUES ('138853948594')")
+
+          @connection.while_preventing_writes do
+            assert_equal 1, @connection.execute("SELECT * FROM ex WHERE data = '138853948594'").entries.count
+          end
+        end
+      end
+
+      def test_doesnt_error_when_a_show_query_is_called_while_preventing_writes
+        @connection.while_preventing_writes do
+          assert_equal 1, @connection.execute("SHOW TIME ZONE").entries.count
+        end
+      end
+
+      def test_doesnt_error_when_a_set_query_is_called_while_preventing_writes
+        @connection.while_preventing_writes do
+          assert_equal [], @connection.execute("SET standard_conforming_strings = on").entries
+        end
+      end
+
       private
 
         def with_example_table(definition = "id serial primary key, number integer, data character varying(255)", &block)