1 files changed, 87 insertions, 0 deletions
diff --git a/activerecord/test/cases/adapters/mysql/datetime_test.rb b/activerecord/test/cases/adapters/mysql/datetime_test.rb
new file mode 100644
index 0000000000..ae00f4e131
--- /dev/null
+++ b/activerecord/test/cases/adapters/mysql/datetime_test.rb
@@ -0,0 +1,87 @@
+require 'cases/helper'
+
+if mysql_56?
+  class DateTimeTest < ActiveRecord::TestCase
+    self.use_transactional_fixtures = false
+
+    class Foo < ActiveRecord::Base; end
+
+    def test_default_datetime_precision
+      ActiveRecord::Base.connection.create_table(:foos, force: true)
+      ActiveRecord::Base.connection.add_column :foos, :created_at, :datetime
+      ActiveRecord::Base.connection.add_column :foos, :updated_at, :datetime
+      assert_nil activerecord_column_option('foos', 'created_at', 'precision')
+    end
+
+    def test_datetime_data_type_with_precision
+      ActiveRecord::Base.connection.create_table(:foos, force: true)
+      ActiveRecord::Base.connection.add_column :foos, :created_at, :datetime, precision: 1
+      ActiveRecord::Base.connection.add_column :foos, :updated_at, :datetime, precision: 5
+      assert_equal 1, activerecord_column_option('foos', 'created_at', 'precision')
+      assert_equal 5, activerecord_column_option('foos', 'updated_at', 'precision')
+    end
+
+    def test_timestamps_helper_with_custom_precision
+      ActiveRecord::Base.connection.create_table(:foos, force: true) do |t|
+        t.timestamps null: true, precision: 4
+      end
+      assert_equal 4, activerecord_column_option('foos', 'created_at', 'precision')
+      assert_equal 4, activerecord_column_option('foos', 'updated_at', 'precision')
+    end
+
+    def test_passing_precision_to_datetime_does_not_set_limit
+      ActiveRecord::Base.connection.create_table(:foos, force: true) do |t|
+        t.timestamps null: true, precision: 4
+      end
+      assert_nil activerecord_column_option('foos', 'created_at', 'limit')
+      assert_nil activerecord_column_option('foos', 'updated_at', 'limit')
+    end
+
+    def test_invalid_datetime_precision_raises_error
+      assert_raises ActiveRecord::ActiveRecordError do
+        ActiveRecord::Base.connection.create_table(:foos, force: true) do |t|
+          t.timestamps null: true, precision: 7
+        end
+      end
+    end
+
+    def test_mysql_agrees_with_activerecord_about_precision
+      ActiveRecord::Base.connection.create_table(:foos, force: true) do |t|
+        t.timestamps null: true, precision: 4
+      end
+      assert_equal 4, mysql_datetime_precision('foos', 'created_at')
+      assert_equal 4, mysql_datetime_precision('foos', 'updated_at')
+    end
+
+    def test_formatting_datetime_according_to_precision
+      ActiveRecord::Base.connection.create_table(:foos, force: true) do |t|
+        t.datetime :created_at, precision: 0
+        t.datetime :updated_at, precision: 4
+      end
+      date = ::Time.utc(2014, 8, 17, 12, 30, 0, 999999)
+      Foo.create!(created_at: date, updated_at: date)
+      assert foo = Foo.find_by(created_at: date)
+      assert_equal date.to_s, foo.created_at.to_s
+      assert_equal date.to_s, foo.updated_at.to_s
+      assert_equal 000000, foo.created_at.usec
+      assert_equal 999900, foo.updated_at.usec
+    end
+
+    private
+
+    def mysql_datetime_precision(table_name, column_name)
+      results = ActiveRecord::Base.connection.exec_query("SELECT column_name, datetime_precision FROM information_schema.columns WHERE table_name = '#{table_name}'")
+      result = results.find do |result_hash|
+        result_hash["column_name"] == column_name
+      end
+      result && result["datetime_precision"]
+    end
+
+    def activerecord_column_option(tablename, column_name, option)
+      result = ActiveRecord::Base.connection.columns(tablename).find do |column|
+        column.name == column_name
+      end
+      result && result.send(option)
+    end
+  end
+end