From 81560df6a13347f09abad52fdb9266465bb9e1af Mon Sep 17 00:00:00 2001
From: Syrus Akbary <me@syrusakbary.com>
Date: Sat, 2 Apr 2016 19:19:40 -0700
Subject: [PATCH] Added JSONString custom scalar

---
 graphene/contrib/django/converter.py          |  5 ++---
 .../contrib/django/tests/test_converter.py    |  5 +++--
 graphene/contrib/django/tests/test_query.py   | 22 +++++++++++++++----
 graphene/core/types/custom_scalars.py         | 21 ++++++++++++++++++
 4 files changed, 44 insertions(+), 9 deletions(-)
 create mode 100644 graphene/core/types/custom_scalars.py

diff --git a/graphene/contrib/django/converter.py b/graphene/contrib/django/converter.py
index 454edab3..3546bc9b 100644
--- a/graphene/contrib/django/converter.py
+++ b/graphene/contrib/django/converter.py
@@ -1,9 +1,8 @@
 from django.db import models
 
-from ...core.classtypes.objecttype import ObjectType
 from ...core.types.definitions import List
-from ...core.types.field import Field
 from ...core.types.scalars import ID, Boolean, Float, Int, String
+from ...core.types.custom_scalars import JSONString
 from ...core.classtypes.enum import Enum
 from .compat import RelatedObject, UUIDField, ArrayField, HStoreField, JSONField, RangeField
 from .utils import get_related_model, import_single_dispatch
@@ -103,7 +102,7 @@ def convert_postgres_array_to_list(field):
 @convert_django_field.register(HStoreField)
 @convert_django_field.register(JSONField)
 def convert_posgres_field_to_string(field):
-    return String(description=field.help_text)
+    return JSONString(description=field.help_text)
 
 
 @convert_django_field.register(RangeField)
diff --git a/graphene/contrib/django/tests/test_converter.py b/graphene/contrib/django/tests/test_converter.py
index 8628ad12..b84c52f1 100644
--- a/graphene/contrib/django/tests/test_converter.py
+++ b/graphene/contrib/django/tests/test_converter.py
@@ -8,6 +8,7 @@ from ..converter import (
 from ..fields import (ConnectionOrListField,
                       DjangoModelField)
 from ..compat import MissingType, ArrayField, HStoreField, JSONField, RangeField
+from graphene.core.types.custom_scalars import JSONString
 
 from .models import Article, Reporter
 
@@ -168,13 +169,13 @@ def test_should_postgres_array_multiple_convert_list():
 @pytest.mark.skipif(HStoreField is MissingType,
                     reason="HStoreField should exist")
 def test_should_postgres_hstore_convert_string():
-    assert_conversion(HStoreField, graphene.String)
+    assert_conversion(HStoreField, JSONString)
 
 
 @pytest.mark.skipif(JSONField is MissingType,
                     reason="JSONField should exist")
 def test_should_postgres_json_convert_string():
-    assert_conversion(JSONField, graphene.String)
+    assert_conversion(JSONField, JSONString)
 
 
 @pytest.mark.skipif(RangeField is MissingType,
diff --git a/graphene/contrib/django/tests/test_query.py b/graphene/contrib/django/tests/test_query.py
index 85cdf103..bf9966bc 100644
--- a/graphene/contrib/django/tests/test_query.py
+++ b/graphene/contrib/django/tests/test_query.py
@@ -66,11 +66,14 @@ def test_should_query_well():
 
 @pytest.mark.skipif(RangeField is MissingType,
                     reason="RangeField should exist")
-def test_should_query_ranges():
-    from django.contrib.postgres.fields import IntegerRangeField
+def test_should_query_postgres_fields():
+    from django.contrib.postgres.fields import IntegerRangeField, ArrayField, JSONField, HStoreField
 
     class Event(models.Model):
-        ages = IntegerRangeField(help_text='Range desc')
+        ages = IntegerRangeField(help_text='The age ranges')
+        data = JSONField(help_text='Data')
+        store = HStoreField()
+        tags = ArrayField(models.CharField(max_length=50))
 
     class EventType(DjangoObjectType):
         class Meta:
@@ -80,19 +83,30 @@ def test_should_query_ranges():
         event = graphene.Field(EventType)
 
         def resolve_event(self, *args, **kwargs):
-            return Event(ages=(0, 10))
+            return Event(
+                ages=(0, 10),
+                data={'angry_babies': True},
+                store={'h': 'store'},
+                tags=['child', 'angry', 'babies']
+            )
 
     schema = graphene.Schema(query=Query)
     query = '''
         query myQuery {
           event {
             ages
+            tags
+            data
+            store
           }
         }
     '''
     expected = {
         'event': {
             'ages': [0, 10],
+            'tags': ['child', 'angry', 'babies'],
+            'data': '{"angry_babies": true}',
+            'store': '{"h": "store"}',
         },
     }
     result = schema.execute(query)
diff --git a/graphene/core/types/custom_scalars.py b/graphene/core/types/custom_scalars.py
new file mode 100644
index 00000000..3497011c
--- /dev/null
+++ b/graphene/core/types/custom_scalars.py
@@ -0,0 +1,21 @@
+import json
+
+from graphql.core.language import ast
+from ...core.classtypes.scalar import Scalar
+
+
+class JSONString(Scalar):
+    '''JSON String'''
+
+    @staticmethod
+    def serialize(dt):
+        return json.dumps(dt)
+
+    @staticmethod
+    def parse_literal(node):
+        if isinstance(node, ast.StringValue):
+            return json.dumps(node.value)
+
+    @staticmethod
+    def parse_value(value):
+        return json.dumps(value)