1 files changed, 18 insertions, 0 deletions
diff --git a/activerecord/test/cases/counter_cache_test.rb b/activerecord/test/cases/counter_cache_test.rb
index 07a182070b..1f5055b2a2 100644
--- a/activerecord/test/cases/counter_cache_test.rb
+++ b/activerecord/test/cases/counter_cache_test.rb
@@ -180,4 +180,22 @@ class CounterCacheTest < ActiveRecord::TestCase
       SpecialTopic.reset_counters(special.id, :lightweight_special_replies)
     end
   end
+
+  test "counters are updated both in memory and in the database on create" do
+    car = Car.new(engines_count: 0)
+    car.engines = [Engine.new, Engine.new]
+    car.save!
+
+    assert_equal 2, car.engines_count
+    assert_equal 2, car.reload.engines_count
+  end
+
+  test "counter caches are updated in memory when the default value is nil" do
+    car = Car.new(engines_count: nil)
+    car.engines = [Engine.new, Engine.new]
+    car.save!
+
+    assert_equal 2, car.engines_count
+    assert_equal 2, car.reload.engines_count
+  end
 end