Properly serialize all JSON primitives in the AR JSON type

Previously we were assuming that the only valid types for encoding were
arrays and hashes. However, any JSON primitive is an accepted value by
both PG and MySQL.

This does involve a minor breaking change in the handling of `default`
in the schema dumper. This is easily worked around, as passing a
hash/array literal would have worked fine in previous versions of Rails.
However, because of this, I will not be backporting this to 4.2 or
earlier.

Fixes #24234

1 files changed, 1 insertions, 5 deletions

diff --git a/activerecord/lib/active_record/type/internal/abstract_json.rb b/activerecord/lib/active_record/type/internal/abstract_json.rb
index 097d1bd363..513c938088 100644
--- a/activerecord/lib/active_record/type/internal/abstract_json.rb
+++ b/activerecord/lib/active_record/type/internal/abstract_json.rb
@@ -17,11 +17,7 @@ module ActiveRecord
         end
 
         def serialize(value)
-          if value.is_a?(::Array) || value.is_a?(::Hash)
-            ::ActiveSupport::JSON.encode(value)
-          else
-            value
-          end
+          ::ActiveSupport::JSON.encode(value)
         end
 
         def accessor