Fixes #402, fix custom JSON/JSONB type support.

gino/dialects/asyncpg.py

@@ -21,6 +21,9 @@
 
 from . import base
 
+JSON_COLTYPE = 114
+JSONB_COLTYPE = 3802
+
 
 class AsyncpgDBAPI(base.BaseDBAPI):
     Error = asyncpg.PostgresError, asyncpg.InterfaceError
@@ -283,6 +286,15 @@ async def _on_metadata_drop_async(self, target, bind, checkfirst=False,
             await self.drop_async(bind=bind, checkfirst=checkfirst)
 
 
+class GinoNullType(sqltypes.NullType):
+    def result_processor(self, dialect, coltype):
+        if coltype == JSON_COLTYPE:
+            return JSON().result_processor(dialect, coltype)
+        if coltype == JSONB_COLTYPE:
+            return JSONB().result_processor(dialect, coltype)
+        return super().result_processor(dialect, coltype)
+
+
 # noinspection PyAbstractClass
 class AsyncpgDialect(PGDialect, base.AsyncDialectMixin):
     driver = 'asyncpg'
@@ -299,6 +311,7 @@ class AsyncpgDialect(PGDialect, base.AsyncDialectMixin):
         {
             ENUM: AsyncEnum,
             sqltypes.Enum: AsyncEnum,
+            sqltypes.NullType: GinoNullType,
         }
     )
 

gino/dialects/base.py

@@ -2,15 +2,12 @@
 import weakref
 
 from sqlalchemy import util
-from sqlalchemy.dialects.postgresql import JSON, JSONB
 
 # noinspection PyProtectedMember
 from ..engine import _SAConnection, _SAEngine, _DBAPIConnection
 from ..loader import Loader
 
 DEFAULT = object()
-JSON_COLTYPE = 114
-JSONB_COLTYPE = 3802
 
 
 class BaseDBAPI:
@@ -375,13 +372,6 @@ def _init_statement_prepared(cls, dialect, connection, dbapi_connection,
         self.cursor = self.create_cursor()
         return self
 
-    def get_result_processor(self, type_, colname, coltype):
-        if coltype == JSON_COLTYPE:
-            return JSON().result_processor(self.dialect, coltype)
-        if coltype == JSONB_COLTYPE:
-            return JSONB().result_processor(self.dialect, coltype)
-        return super().get_result_processor(type_, colname, coltype)
-
 
 class AsyncDialectMixin:
     cursor_cls = DBAPICursor

tests/test_json.py

@@ -176,13 +176,21 @@ class Test(db.Model):
             age = db.IntegerProperty(default=18)
 
 
-async def test_t291(bind):
+async def test_t291_t402(bind):
     from gino.dialects.asyncpg import JSON, JSONB
 
+    class CustomJSONB(db.TypeDecorator):
+        impl = JSONB
+
+        def process_result_value(self, *_):
+            return 123
+
     class PropsTest(db.Model):
         __tablename__ = 'props_test_291'
         profile = db.Column(JSONB(), nullable=False, server_default='{}')
         profile1 = db.Column(JSON(), nullable=False, server_default='{}')
+        profile2 = db.Column(CustomJSONB(),
+                             nullable=False, server_default='{}')
 
         bool = db.BooleanProperty()
         bool1 = db.BooleanProperty(prop_name='profile1')
@@ -197,5 +205,10 @@ class PropsTest(db.Model):
         assert isinstance(profile, dict)
         profile1 = await bind.scalar('SELECT profile1 FROM props_test_291')
         assert isinstance(profile1, dict)
+        profile2 = await bind.scalar('SELECT profile2 FROM props_test_291')
+        assert isinstance(profile2, dict)
+        custom_profile2 = await bind.scalar(PropsTest.select('profile2'))
+        assert isinstance(custom_profile2, int)
+        assert custom_profile2 == 123
     finally:
         await PropsTest.gino.drop()