Merge pull request #56 from tartiflette/ISSUE-55

ISSUE-55 - Provides a context factory parameter

Author: Maximilien-R

CHANGELOG.md

@@ -12,6 +12,8 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 ## [Released]
 
 - [1.x.x]
+  - [1.1.x]
+    - [1.1.0](./changelogs/1.1.0.md) - 2019-10-02
   - [1.0.x]
     - [1.0.0](./changelogs/1.0.0.md) - 2019-09-12
 - [0.x.x]

changelogs/1.1.0.md

@@ -0,0 +1,26 @@
+# [1.1.0] -- 2019-10-02
+
+## Added
+
+- [ISSUE-55](https://github.com/tartiflette/tartiflette-aiohttp/issues/55) - Add
+a new optional `context_factory` parameter to the `register_graphql_handlers`
+function. This parameter can take a coroutine function which will be called on
+each request with the following signature:
+    ```python
+    async def context_factory(
+        context: Dict[str, Any], req: "aiohttp.web.Request"
+    ) -> Dict[str, Any]:
+        """
+        Generates a new context.
+        :param context: the value filled in through the `executor_context`
+        parameter
+        :param req: the incoming aiohttp request instance
+        :type context: Dict[str, Any]
+        :type req: aiohttp.web.Request
+        :return: the context for the incoming request
+        :rtype: Dict[str, Any]
+        """
+    ```
+
+The aim of this function will be to returns the context which will be forwarded
+to the Tartiflette engine on the `execute` or `subscribe` method.

changelogs/next.md

@@ -1,7 +1,7 @@
-# [next]
+# [Next]
 
 ## Added
 
 ## Changed
 
-## Fixed
+## Fixed

setup.py

@@ -13,7 +13,7 @@
     "isort==4.3.21",
 ]
 
-_VERSION = "1.0.0"
+_VERSION = "1.1.0"
 
 _PACKAGES = find_packages(exclude=["tests*"])
 

tartiflette_aiohttp/__init__.py

@@ -1,10 +1,11 @@
 import json
 
 from functools import partial
-from inspect import iscoroutine
-from typing import Any, Dict, List, Optional, Union
+from inspect import iscoroutine, iscoroutinefunction
+from typing import Any, Callable, Dict, List, Optional, Union
 
 from tartiflette import Engine
+from tartiflette_aiohttp._context_factory import default_context_factory
 from tartiflette_aiohttp._graphiql import graphiql_handler
 from tartiflette_aiohttp._handler import Handlers
 from tartiflette_aiohttp._subscription_ws_handler import (
@@ -35,15 +36,15 @@ def validate_and_compute_graphiql_option(
 def _set_subscription_ws_handler(
     app: "Application",
     subscription_ws_endpoint: Optional[str],
-    context: Dict[str, Any],
+    context_factory: Callable,
 ) -> None:
     if not subscription_ws_endpoint:
         return
 
     app.router.add_route(
         "GET",
         subscription_ws_endpoint,
-        AIOHTTPSubscriptionHandler(app, context),
+        AIOHTTPSubscriptionHandler(app, context_factory),
     )
 
 
@@ -116,6 +117,7 @@ def register_graphql_handlers(
     engine_modules: Optional[
         List[Union[str, Dict[str, Union[str, Dict[str, str]]]]]
     ] = None,
+    context_factory: Optional[Callable] = None,
 ) -> "Application":
     """Register a Tartiflette Engine to an app
 
@@ -133,10 +135,12 @@ def register_graphql_handlers(
         graphiql_enabled {bool} -- Determines whether or not we should handle a GraphiQL endpoint (default: {False})
         graphiql_options {dict} -- Customization options for the GraphiQL instance (default: {None})
         engine_modules: {Optional[List[Union[str, Dict[str, Union[str, Dict[str, str]]]]]]} -- Module to import (default:{None})
+        context_factory: {Optional[Callable]} -- coroutine function in charge of generating the context for each request (default: {None})
 
     Raises:
         Exception -- On bad sdl/engine parameter combinaison.
         Exception -- On unsupported HTTP Method.
+        Exception -- if `context_factory` is filled in without a coroutine function.
 
     Return:
         The app object.
@@ -150,6 +154,16 @@ def register_graphql_handlers(
     if not executor_http_methods:
         executor_http_methods = ["GET", "POST"]
 
+    if context_factory is None:
+        context_factory = default_context_factory
+
+    if not iscoroutinefunction(context_factory):
+        raise Exception(
+            "`context_factory` parameter should be a coroutine function."
+        )
+
+    context_factory = partial(context_factory, executor_context)
+
     if not engine:
         engine = Engine()
 
@@ -174,14 +188,14 @@ def register_graphql_handlers(
                 executor_http_endpoint,
                 partial(
                     getattr(Handlers, "handle_%s" % method.lower()),
-                    executor_context,
+                    context_factory=context_factory,
                 ),
             )
         except AttributeError:
             raise Exception("Unsupported < %s > http method" % method)
 
     _set_subscription_ws_handler(
-        app, subscription_ws_endpoint, executor_context
+        app, subscription_ws_endpoint, context_factory
     )
 
     _set_graphiql_handler(

tartiflette_aiohttp/_context_factory.py

@@ -0,0 +1,19 @@
+from typing import Any, Dict
+
+__all__ = ("default_context_factory",)
+
+
+async def default_context_factory(
+    context: Dict[str, Any], req: "aiohttp.web.Request"
+) -> Dict[str, Any]:
+    """
+    Generates a new context.
+    :param context: the value filled in through the `executor_context`
+    parameter
+    :param req: the incoming aiohttp request instance
+    :type context: Dict[str, Any]
+    :type req: aiohttp.web.Request
+    :return: the context for the incoming request
+    :rtype: Dict[str, Any]
+    """
+    return {**context, "req": req}

tartiflette_aiohttp/_handler.py

@@ -1,8 +1,6 @@
 import json
 import logging
 
-from copy import copy
-
 from aiohttp import web
 
 logger = logging.getLogger(__name__)
@@ -34,8 +32,11 @@ def prepare_response(data):
     return web.json_response(data, headers=headers, dumps=json.dumps)
 
 
-async def _handle_query(req, query, query_vars, operation_name, context):
-    context = copy(context)
+async def _handle_query(
+    req, query, query_vars, operation_name, context_factory
+):
+    context = await context_factory(req)
+
     try:
         if not operation_name:
             operation_name = None
@@ -94,23 +95,23 @@ async def _post_params(req):
 
 class Handlers:
     @staticmethod
-    async def _handle(param_func, user_c, req):
-        user_c["req"] = req
-
+    async def _handle(param_func, req, context_factory):
         try:
             qry, qry_vars, oprn_name = await param_func(req)
             return prepare_response(
-                await _handle_query(req, qry, qry_vars, oprn_name, user_c)
+                await _handle_query(
+                    req, qry, qry_vars, oprn_name, context_factory
+                )
             )
         except BadRequestError as e:
             return prepare_response(
                 {"data": None, "errors": _format_errors([e])}
             )
 
     @staticmethod
-    async def handle_get(user_context, req):
-        return await Handlers._handle(_get_params, user_context, req)
+    async def handle_get(req, context_factory):
+        return await Handlers._handle(_get_params, req, context_factory)
 
     @staticmethod
-    async def handle_post(user_context, req):
-        return await Handlers._handle(_post_params, user_context, req)
+    async def handle_post(req, context_factory):
+        return await Handlers._handle(_post_params, req, context_factory)

tartiflette_aiohttp/_subscription_ws_handler.py

@@ -1,7 +1,7 @@
 import json
 
 from asyncio import ensure_future, shield, wait
-from typing import Any, AsyncIterator, Dict, Optional, Set
+from typing import Any, AsyncIterator, Callable, Dict, Optional, Set
 
 from aiohttp import WSMsgType, web
 
@@ -79,9 +79,11 @@ async def close(self, code: int) -> None:
 
 
 class AIOHTTPSubscriptionHandler:
-    def __init__(self, app: "Application", context: Dict[str, Any]) -> None:
+    def __init__(self, app: "Application", context_factory: Callable) -> None:
         self._app: "Application" = app
-        self._context = context
+        self._context_factory = context_factory
+        self._socket: Optional["web.WebSocketResponse"] = None
+        self._context: Optional[Dict[str, Any]] = None
 
     async def _send_message(
         self,
@@ -255,9 +257,8 @@ async def _handle_request(self) -> None:
         await self._on_close(connection_context, tasks)
 
     async def __call__(self, request: "Request") -> "WebSocketResponse":
-        self._socket = web.WebSocketResponse(  # pylint: disable=attribute-defined-outside-init
-            protocols=(WS_PROTOCOL,)
-        )
+        self._socket = web.WebSocketResponse(protocols=(WS_PROTOCOL,))
+        self._context = await self._context_factory(request)
         await self._socket.prepare(request)
         await shield(self._handle_request())
         return self._socket

tests/integration/test_handlers.py

@@ -1,7 +1,10 @@
+from functools import partial
 from unittest.mock import Mock
 
 import pytest
 
+from tartiflette_aiohttp import default_context_factory
+
 
 @pytest.mark.asyncio
 async def test_handler__handle_query__context_unicity():
@@ -31,18 +34,18 @@ async def resolver_hello(parent, args, ctx, info):
     a_req = Mock()
     a_req.app = {"ttftt_engine": tftt_engine}
 
-    ctx = {}
+    context_factory = partial(default_context_factory, {})
 
     await _handle_query(
-        a_req, 'query { hello(name: "Chuck") }', None, None, ctx
+        a_req, 'query { hello(name: "Chuck") }', None, None, context_factory
     )
 
     await _handle_query(
-        a_req, 'query { hello(name: "Chuck") }', None, None, ctx
+        a_req, 'query { hello(name: "Chuck") }', None, None, context_factory
     )
 
     b_response = await _handle_query(
-        a_req, 'query { hello(name: "Chuck") }', None, None, ctx
+        a_req, 'query { hello(name: "Chuck") }', None, None, context_factory
     )
 
     assert b_response == {"data": {"hello": "hello 1"}}
@@ -71,7 +74,7 @@ async def resolver_hello(parent, args, ctx, info):
     a_req = Mock()
     a_req.app = {"ttftt_engine": tftt_engine}
 
-    ctx = {}
+    context_factory = partial(default_context_factory, {})
 
     result = await _handle_query(
         a_req,
@@ -82,7 +85,7 @@ async def resolver_hello(parent, args, ctx, info):
         """,
         None,
         "B",
-        ctx,
+        context_factory,
     )
 
     assert result == {"data": {"hello": "hello Bar"}}

tests/unit/test_handlers.py

@@ -1,9 +1,12 @@
+from functools import partial
 from unittest.mock import Mock
 
 import pytest
 
 from asynctest import CoroutineMock
 
+from tartiflette_aiohttp import default_context_factory
+
 
 @pytest.mark.parametrize(
     "value,expected",
@@ -32,7 +35,11 @@ async def test_handler__handle_query():
     a_req.app = {"ttftt_engine": an_engine}
 
     a_response = await _handle_query(
-        a_req, "query a {}", {"B": "C"}, "a", {"D": "E"}
+        a_req,
+        "query a {}",
+        {"B": "C"},
+        "a",
+        partial(default_context_factory, {"D": "E"}),
     )
 
     assert a_response == "T"
@@ -42,7 +49,7 @@ async def test_handler__handle_query():
             {
                 "query": "query a {}",
                 "variables": {"B": "C"},
-                "context": {"D": "E"},
+                "context": {"D": "E", "req": a_req},
                 "operation_name": "a",
             },
         )
@@ -60,7 +67,11 @@ async def test_handler__handle_query_nok():
     a_req.app = {}
 
     a_response = await _handle_query(
-        a_req, "query a {}", {"B": "C"}, "a", {"D": "E"}
+        a_req,
+        "query a {}",
+        {"B": "C"},
+        "a",
+        partial(default_context_factory, {"D": "E"}),
     )
 
     assert a_response == {
@@ -179,7 +190,9 @@ async def test_handler__handle():
 
     a_method = CoroutineMock(return_value=("a", "b", "c"))
 
-    await Handlers._handle(a_method, {}, a_req)
+    await Handlers._handle(
+        a_method, a_req, partial(default_context_factory, {})
+    )
 
     assert a_method.call_args_list == [((a_req,),)]