Added annotated resolver and context

graphene/__init__.py

@@ -32,6 +32,8 @@ if not __SETUP__:
         Argument,
         Dynamic,
         Union,
+        Context,
+        ResolveInfo
     )
     from .relay import (
         Node,
@@ -74,6 +76,8 @@ if not __SETUP__:
         'ConnectionField',
         'PageInfo',
         'lazy_import',
+        'Context',
+        'ResolveInfo',
 
         # Deprecated
         'AbstractType',

graphene/types/__init__.py

@@ -1,4 +1,5 @@
 # flake8: noqa
+from graphql.execution.base import ResolveInfo
 
 from .objecttype import ObjectType
 from .interface import Interface
@@ -13,6 +14,7 @@ from .argument import Argument
 from .inputobjecttype import InputObjectType
 from .dynamic import Dynamic
 from .union import Union
+from .context import Context
 
 # Deprecated
 from .abstracttype import AbstractType
@@ -38,6 +40,8 @@ __all__ = [
     'Argument',
     'Dynamic',
     'Union',
+    'Context',
+    'ResolveInfo',
 
     # Deprecated
     'AbstractType',

graphene/types/context.py

@@ -0,0 +1,4 @@
+class Context(object):
+    def __init__(self, **params):
+        for key, value in params.items():
+            setattr(self,key, value)

graphene/utils/annotate.py

@@ -3,8 +3,8 @@ from functools import wraps
 from ..pyutils.compat import signature
 
 
-def annotate(_func=None, **annotations):
-    if not six.PY2:
+def annotate(_func=None, _trigger_warning=True, **annotations):
+    if not six.PY2 and _trigger_warning:
         print(
             "annotate is intended for use in Python 2 only, as you can use type annotations Python 3.\n"
             "Read more in https://docs.python.org/3/library/typing.html"

graphene/utils/annotated_resolver.py

@@ -0,0 +1,36 @@
+from ..pyutils.compat import signature
+from functools import wraps
+
+from ..types import Context, ResolveInfo
+
+
+def annotated_resolver(func):
+    func_signature = signature(func)
+
+    _context_var = None
+    _info_var = None
+    for key, parameter in func_signature.parameters.items():
+        param_type = parameter.annotation
+        if param_type is Context:
+            _context_var = key
+        elif param_type is ResolveInfo:
+            _info_var = key
+        continue
+
+    # We generate different functions as it will be faster
+    # than calculating the args on the fly when executing
+    # the function resolver.
+    if _context_var and _info_var:
+        def inner(root, args, context, info):
+            return func(root, **dict(args, **{_info_var: info, _context_var: context}))
+    elif _context_var:
+        def inner(root, args, context, info):
+            return func(root, **dict(args, **{_context_var: context}))
+    elif _info_var:
+        def inner(root, args, context, info):
+            return func(root, **dict(args, **{_info_var: info}))
+    else:
+        def inner(root, args, context, info):
+            return func(root, **args)
+
+    return wraps(func)(inner)

graphene/utils/tests/test_annotated_resolver.py

@@ -0,0 +1,39 @@
+import pytest
+from ..annotate import annotate
+from ..annotated_resolver import annotated_resolver
+
+from ...types import Context, ResolveInfo
+
+@annotate
+def func(root, **args):
+    return root, args, None, None
+
+@annotate(context=Context)
+def func_with_context(root, context, **args):
+    return root, args, context, None
+
+@annotate(info=ResolveInfo)
+def func_with_info(root, info, **args):
+    return root, args, None, info
+
+@annotate(context=Context, info=ResolveInfo)
+def func_with_context_and_info(root, context, info, **args):
+    return root, args, context, info
+
+root = 1
+args = {
+    'arg': 0
+}
+context = 2
+info = 3
+
+@pytest.mark.parametrize("func,expected", [
+    (func, (1, {'arg': 0}, None, None)),
+    (func_with_context, (1, {'arg': 0}, 2, None)),
+    (func_with_info, (1, {'arg': 0}, None, 3)),
+    (func_with_context_and_info, (1, {'arg': 0}, 2, 3)),
+])
+def test_annotated_resolver(func, expected):
+    resolver_func = annotated_resolver(func)
+    resolved = resolver_func(root, args, context, info)
+    assert resolved == expected