1 files changed, 80 insertions, 2 deletions
diff --git a/activerecord/test/cases/cache_key_test.rb b/activerecord/test/cases/cache_key_test.rb
index 3a569f226e..3a06b1c795 100644
--- a/activerecord/test/cases/cache_key_test.rb
+++ b/activerecord/test/cases/cache_key_test.rb
@@ -44,10 +44,88 @@ module ActiveRecord
 
     test "cache_key_with_version always has both key and version" do
       r1 = CacheMeWithVersion.create
-      assert_equal "active_record/cache_key_test/cache_me_with_versions/#{r1.id}-#{r1.updated_at.to_s(:usec)}", r1.cache_key_with_version
+      assert_equal "active_record/cache_key_test/cache_me_with_versions/#{r1.id}-#{r1.updated_at.utc.to_s(:usec)}", r1.cache_key_with_version
 
       r2 = CacheMe.create
-      assert_equal "active_record/cache_key_test/cache_mes/#{r2.id}-#{r2.updated_at.to_s(:usec)}", r2.cache_key_with_version
+      assert_equal "active_record/cache_key_test/cache_mes/#{r2.id}-#{r2.updated_at.utc.to_s(:usec)}", r2.cache_key_with_version
+    end
+
+    test "cache_version is the same when it comes from the DB or from the user" do
+      skip("Mysql2 does not return a string value for updated_at") if current_adapter?(:Mysql2Adapter)
+
+      record = CacheMeWithVersion.create
+      record_from_db = CacheMeWithVersion.find(record.id)
+      assert_not_called(record_from_db, :updated_at) do
+        record_from_db.cache_version
+      end
+
+      assert_equal record.cache_version, record_from_db.cache_version
+    end
+
+    test "cache_version does not truncate zeros when timestamp ends in zeros" do
+      skip("Mysql2 does not return a string value for updated_at") if current_adapter?(:Mysql2Adapter)
+
+      travel_to Time.now.beginning_of_day do
+        record = CacheMeWithVersion.create
+        record_from_db = CacheMeWithVersion.find(record.id)
+        assert_not_called(record_from_db, :updated_at) do
+          record_from_db.cache_version
+        end
+
+        assert_equal record.cache_version, record_from_db.cache_version
+      end
+    end
+
+    test "cache_version calls updated_at when the value is generated at create time" do
+      record = CacheMeWithVersion.create
+      assert_called(record, :updated_at) do
+        record.cache_version
+      end
+    end
+
+    test "cache_version does NOT call updated_at when value is from the database" do
+      skip("Mysql2 does not return a string value for updated_at") if current_adapter?(:Mysql2Adapter)
+
+      record = CacheMeWithVersion.create
+      record_from_db = CacheMeWithVersion.find(record.id)
+      assert_not_called(record_from_db, :updated_at) do
+        record_from_db.cache_version
+      end
+    end
+
+    test "cache_version does call updated_at when it is assigned via a Time object" do
+      record = CacheMeWithVersion.create
+      record_from_db = CacheMeWithVersion.find(record.id)
+      assert_called(record_from_db, :updated_at) do
+        record_from_db.updated_at = Time.now
+        record_from_db.cache_version
+      end
+    end
+
+    test "cache_version does call updated_at when it is assigned via a string" do
+      record = CacheMeWithVersion.create
+      record_from_db = CacheMeWithVersion.find(record.id)
+      assert_called(record_from_db, :updated_at) do
+        record_from_db.updated_at = Time.now.to_s
+        record_from_db.cache_version
+      end
+    end
+
+    test "cache_version does call updated_at when it is assigned via a hash" do
+      record = CacheMeWithVersion.create
+      record_from_db = CacheMeWithVersion.find(record.id)
+      assert_called(record_from_db, :updated_at) do
+        record_from_db.updated_at = { 1 => 2016, 2 => 11, 3 => 12, 4 => 1, 5 => 2, 6 => 3, 7 => 22 }
+        record_from_db.cache_version
+      end
+    end
+
+    test "updated_at on class but not on instance raises an error" do
+      record = CacheMeWithVersion.create
+      record_from_db = CacheMeWithVersion.where(id: record.id).select(:id).first
+      assert_raises(ActiveModel::MissingAttributeError) do
+        record_from_db.cache_version
+      end
     end
   end
 end