JSON is still an adapter specific type.

Several changes were made in #21110 which I am strongly opposed to.
(this is what I get for going on vacation. :trollface:) No type should
be introduced into the generic `ActiveRecord::Type` namespace, and
*certainly* should not be registered into the registry unconstrained
unless it is supported by *all* adapters (which basically means that it
was specified in the ANSI SQL standard).

I do not think `# :nodoc:` ing the type is sufficient, as it still makes
the code of Rails itself very unclear as to what the role of that class
is. While I would argue that this shouldn't even be a super class, and
that MySql and PG's JSON types are only superficially duplicated (they
might look the same but will change for different reasons in the
future).

However, I don't feel strongly enough about it as a point of contention
(and the biggest cost of harming the blameability has already occured),
so I simply moved the superclass into a namespace where its role is
absolutely clear.

After this change, `attribute :foo, :json` will once again work with
MySQL and PG, but not with Sqlite3 or any third party adapters.

Unresolved questions
--------------------

The types that and adapter publishes (at least those are unique to that
adapter, and not adding additional behavior like `MysqlString` should
probably be part of the adapter's public API. Should we standardize the
namespace for these, and document them?

1 files changed, 2 insertions, 2 deletions

diff --git a/activerecord/lib/active_record/type.rb b/activerecord/lib/active_record/type.rb
index 8f56a37f3c..53f3b53bec 100644
--- a/activerecord/lib/active_record/type.rb
+++ b/activerecord/lib/active_record/type.rb
@@ -10,7 +10,6 @@ require 'active_record/type/decimal'
 require 'active_record/type/decimal_without_scale'
 require 'active_record/type/float'
 require 'active_record/type/integer'
-require 'active_record/type/json'
 require 'active_record/type/serialized'
 require 'active_record/type/string'
 require 'active_record/type/text'
@@ -21,6 +20,8 @@ require 'active_record/type/adapter_specific_registry'
 require 'active_record/type/type_map'
 require 'active_record/type/hash_lookup_type_map'
 
+require 'active_record/type/internal/abstract_json'
+
 module ActiveRecord
   module Type
     @registry = AdapterSpecificRegistry.new
@@ -60,7 +61,6 @@ module ActiveRecord
     register(:decimal, Type::Decimal, override: false)
     register(:float, Type::Float, override: false)
     register(:integer, Type::Integer, override: false)
-    register(:json, Type::Json, override: false)
     register(:string, Type::String, override: false)
     register(:text, Type::Text, override: false)
     register(:time, Type::Time, override: false)