Improved resolver logic middleware by using promises

graphene/core/schema.py

@@ -8,20 +8,11 @@ from graphql.utils.schema_printer import print_schema
 from graphene import signals
 
 from ..plugins import CamelCase, PluginManager
+from ..utils import promise_middleware
 from .classtypes.base import ClassType
 from .types.base import InstanceType
 
 
-class ACI(object):
-    def __init__(self, args, context, info):
-        self.args = args
-        self.context = context
-        self.info = info
-
-    def __repr__(self):
-        return "ACI(args={}, context={}, info={})".format(repr(self.args), repr(self.context), repr(self.info))
-
-
 class GraphQLSchema(_GraphQLSchema):
 
     def __init__(self, schema, *args, **kwargs):
@@ -121,25 +112,9 @@ class Schema(object):
             raise KeyError('Type %r not found in %r' % (type_name, self))
         return self._types_names[type_name]
 
-    def resolve(self, resolver, root, args, context, info):
-        aci = ACI(args, context, info)
-        plugins_process_aci = self.plugins.get_plugin_functions('process_aci')
-        plugins_process_response = self.plugins.get_plugin_functions('process_response')
-        for process_aci in plugins_process_aci:
-            processed_aci = process_aci(aci)
-            if processed_aci is None:
-                continue
-            return processed_aci
-
-        response = resolver(root, aci.args, aci.context, aci.info)
-
-        for process_response in plugins_process_response:
-            processed_response = process_response(response, aci)
-            if processed_response is None:
-                continue
-            return processed_response
-
-        return response
+    def resolver_with_middleware(self, resolver):
+        plugins_resolve = self.plugins.get_plugin_functions('resolve')
+        return promise_middleware(resolver, plugins_resolve)
 
     @property
     def types(self):

graphene/core/tests/test_old_fields.py

@@ -93,7 +93,7 @@ def test_field_resolve():
     f = StringField(required=True, resolve=lambda *args: 'RESOLVED').as_field()
     f.contribute_to_class(MyOt, 'field_name')
     field_type = schema.T(f)
-    assert 'RESOLVED' == field_type.resolver(MyOt, None, None, None)
+    assert 'RESOLVED' == field_type.resolver(MyOt, None, None, None).value
 
 
 def test_field_resolve_type_custom():

graphene/core/types/field.py

@@ -115,10 +115,13 @@ class Field(NamedType, OrderedType):
             resolver = wrapped_func
 
         assert type, 'Internal type for field %s is None' % str(self)
-        return GraphQLField(type, args=schema.T(arguments),
-                            resolver=partial(schema.resolve, resolver),
-                            deprecation_reason=self.deprecation_reason,
-                            description=description,)
+        return GraphQLField(
+            type,
+            args=schema.T(arguments),
+            resolver=schema.resolver_with_middleware(resolver),
+            deprecation_reason=self.deprecation_reason,
+            description=description,
+        )
 
     def __repr__(self):
         """
@@ -172,7 +175,8 @@ class InputField(NamedType, OrderedType):
     def internal_type(self, schema):
         return GraphQLInputObjectField(
             schema.T(self.type),
-            default_value=self.default, description=self.description)
+            default_value=self.default, description=self.description
+        )
 
 
 class FieldsGroupType(GroupNamedType):

graphene/core/types/tests/test_field.py

@@ -24,7 +24,7 @@ def test_field_internal_type():
     assert field.attname == 'my_field'
     assert isinstance(type, GraphQLField)
     assert type.description == 'My argument'
-    assert type.resolver(None, {}, None, None) == 'RESOLVED'
+    assert type.resolver(None, {}, None, None).value == 'RESOLVED'
     assert type.type == GraphQLString
 
 
@@ -43,7 +43,7 @@ def test_field_objectype_resolver():
     type = schema.T(field)
     assert isinstance(type, GraphQLField)
     assert type.description == 'Custom description'
-    assert type.resolver(Query(), {}, None, None) == 'RESOLVED'
+    assert type.resolver(Query(), {}, None, None).value == 'RESOLVED'
 
 
 def test_field_custom_name():
@@ -161,7 +161,7 @@ def test_field_resolve_argument():
     schema = Schema(query=Query)
 
     type = schema.T(field)
-    assert type.resolver(None, {'firstName': 'Peter'}, None, None) == 'Peter'
+    assert type.resolver(None, {'firstName': 'Peter'}, None, None).value == 'Peter'
 
 
 def test_field_resolve_vars():
@@ -216,7 +216,6 @@ def test_field_resolve_object():
         att_func = field_func
 
     assert field.resolver(Root, {}, None) is True
-    assert field.resolver(Root, {}, None) is True
 
 
 def test_field_resolve_source_object():
@@ -235,4 +234,3 @@ def test_field_resolve_source_object():
         att_func = field_func
 
     assert field.resolver(Root, {}, None) is True
-    assert field.resolver(Root, {}, None) is True

graphene/plugins/camel_case.py

@@ -6,5 +6,6 @@ class CamelCase(object):
     def get_default_namedtype_name(self, value):
         return to_camel_case(value)
 
-    def process_aci(self, aci):
-        aci.args = ProxySnakeDict(aci.args)
+    def resolve(self, next, root, args, context, info):
+        args = ProxySnakeDict(args)
+        return next(root, args, context, info)

graphene/utils/__init__.py

@@ -3,6 +3,7 @@ from .proxy_snake_dict import ProxySnakeDict
 from .caching import cached_property, memoize
 from .maybe_func import maybe_func
 from .misc import enum_to_graphql_enum
+from .promise_middleware import promise_middleware
 from .resolve_only_args import resolve_only_args
 from .lazylist import LazyList
 from .wrap_resolver_function import with_context, wrap_resolver_function
@@ -10,5 +11,5 @@ from .wrap_resolver_function import with_context, wrap_resolver_function
 
 __all__ = ['to_camel_case', 'to_snake_case', 'to_const', 'ProxySnakeDict',
            'cached_property', 'memoize', 'maybe_func', 'enum_to_graphql_enum',
-           'resolve_only_args', 'LazyList', 'with_context',
+           'promise_middleware', 'resolve_only_args', 'LazyList', 'with_context',
            'wrap_resolver_function']

graphene/utils/promise_middleware.py

@@ -0,0 +1,17 @@
+from functools import partial
+from itertools import chain
+
+from promise import Promise
+
+
+def promise_middleware(func, middlewares):
+    middlewares = chain((func, make_it_promise), middlewares)
+    past = None
+    for m in middlewares:
+        past = partial(m, past) if past else m
+
+    return past
+
+
+def make_it_promise(next, *a, **b):
+    return Promise.resolve(next(*a, **b))