Mikro ORM: error while updating property having custom type

[kkhanhluu]

In my model, I'm having a property that has custom mikro orm type:

@Property({ type: CalendarDateType })
  createdAt: CalendarDate | null = null;

The CalendateDateType is a class which extends class Type from mikro-orm and it has following the methods convertToDatabaseValue and convertToJSValue.

When I used pg-mem with mikro-orm and tried to update lockedAt property of 1 entity like this:

obj.createdAt = new CalendarDate();

The record in database was updated correctly but I got the following error:

update "obj" set "created_at" = '2022-01-01' where "id" = 'some_id' - 
ERROR: invalid input syntax for type json. 
DETAIL: Unexpected number in JSON at position 4 
🐜 This seems to be an execution error, which means that your request syntax seems okay, 
but the resulting statement cannot be executed → Probably not a pg-mem error.

Did someone encounter such the problem? Thanks in advanced.