1 files changed, 20 insertions, 0 deletions
diff --git a/activerecord/test/cases/time_precision_test.rb b/activerecord/test/cases/time_precision_test.rb
index 086500de38..2f534ea110 100644
--- a/activerecord/test/cases/time_precision_test.rb
+++ b/activerecord/test/cases/time_precision_test.rb
@@ -45,6 +45,26 @@ if subsecond_precision_supported?
       assert_equal 123456000, foo.finish.nsec
     end
 
+    unless current_adapter?(:Mysql2Adapter)
+      def test_no_time_precision_isnt_truncated_on_assignment
+        @connection.create_table(:foos, force: true)
+        @connection.add_column :foos, :start,  :time
+        @connection.add_column :foos, :finish, :time, precision: 6
+
+        time = ::Time.now.change(nsec: 123)
+        foo = Foo.new(start: time, finish: time)
+
+        assert_equal 123, foo.start.nsec
+        assert_equal 0, foo.finish.nsec
+
+        foo.save!
+        foo.reload
+
+        assert_equal 0, foo.start.nsec
+        assert_equal 0, foo.finish.nsec
+      end
+    end
+
     def test_passing_precision_to_time_does_not_set_limit
       @connection.create_table(:foos, force: true) do |t|
         t.time :start,  precision: 3