On some databases, columns with the text data type might want to be serialized. The ToJSON helper defaults prevented this, so it needed to be subclassed as well as some of the code duplicated. Adding the new method unserializable_data_types simplifies overriding the defaults.
Coverage increased (+0.007%) to 98.417% when pulling fee641601041fff668b57ffff374a45c8a9b6f27 on kwakwaversal:master into 0e9a59fd75c3e2ee74ea75ab4c4eaea9f8c18337 on frioux:master.
On some databases, columns with the text data type might want to be serialized. The ToJSON helper defaults prevented this, so it needed to be subclassed as well as some of the code duplicated. Adding the new method unserializable_data_types simplifies overriding the defaults.
Fixes #79