fix JSONPathType bind processor for asyncpg

gino/dialects/asyncpg.py

@@ -9,7 +9,8 @@
     CreateEnumType,
     DropEnumType,
     JSON,
-    JSONB
+    JSONB,
+    json,
 )
 from sqlalchemy.dialects.postgresql.base import (
     ENUM,
@@ -333,6 +334,20 @@ def result_processor(self, dialect, coltype):
         return super().result_processor(dialect, coltype)
 
 
+class AsyncpgJSONPathType(json.JSONPathType):
+    def bind_processor(self, dialect):
+        super_proc = self.string_bind_processor(dialect)
+
+        def process(value):
+            assert isinstance(value, util.collections_abc.Sequence)
+            if super_proc:
+                return [super_proc(util.text_type(elem)) for elem in value]
+            else:
+                return [util.text_type(elem) for elem in value]
+
+        return process
+
+
 # noinspection PyAbstractClass
 class AsyncpgDialect(PGDialect, base.AsyncDialectMixin):
     driver = 'asyncpg'
@@ -350,6 +365,7 @@ class AsyncpgDialect(PGDialect, base.AsyncDialectMixin):
             ENUM: AsyncEnum,
             sqltypes.Enum: AsyncEnum,
             sqltypes.NullType: GinoNullType,
+            sqltypes.JSON.JSONPathType: AsyncpgJSONPathType,
         }
     )
 

tests/test_json.py

@@ -233,3 +233,20 @@ class PropsTest(db.Model):
         assert custom_profile2 == 123
     finally:
         await PropsTest.gino.drop()
+
+
+async def test_json_path(bind):
+    from gino.dialects.asyncpg import JSONB
+
+    class PathTest(db.Model):
+        __tablename__ = 'path_test_json_path'
+        data = db.Column(JSONB())
+
+    await PathTest.gino.create()
+    try:
+        t1 = await PathTest.create(data=dict(a=dict(b='c')))
+        t2 = await PathTest.query.where(
+            PathTest.data[('a', 'b')].astext == 'c').gino.first()
+        assert t1.data == t2.data
+    finally:
+        await PathTest.gino.drop()