Incorporate scope inference (#101)

Taking advantage of adriangb/di@b0cd073 to make things a bit less verbose and error prone.

pyproject.toml

@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "xpresso"
-version = "0.41.2"
+version = "0.42.0"
 description = "A developer centric, performant Python web framework"
 authors = ["Adrian Garcia Badaracco <[email protected]>"]
 readme = "README.md"
@@ -36,7 +36,7 @@ classifiers = [
 
 [tool.poetry.dependencies]
 python = ">=3.7,<4"
-di = ">=0.69.0"
+di = ">=0.70.0"
 anyio = ">=3.4.0,<5"
 starlette = ">=0.17.1,<1"
 typing-extensions = { version = ">=3", python = "<3.9" }

xpresso/_utils/scope_resolver.py

@@ -0,0 +1,31 @@
+from typing import Any, Sequence
+
+from di.api.dependencies import DependantBase
+from di.api.scopes import Scope
+
+
+def endpoint_scope_resolver(
+    dep: DependantBase[Any],
+    sub_dependant_scopes: Sequence[Scope],
+    _: Sequence[Scope],
+) -> Scope:
+    """Resolve scopes by defaulting to "connection"
+    unless a sub-dependency has an "endpoint" scope
+    in which case we drop down to that scope
+    """
+    if dep.scope is not None:
+        return dep.scope
+    if "endpoint" in sub_dependant_scopes:
+        return "endpoint"
+    return "connection"
+
+
+def lifespan_scope_resolver(
+    dep: DependantBase[Any],
+    sub_dependant_scopes: Sequence[Scope],
+    _: Sequence[Scope],
+) -> Scope:
+    """Always default to the "app" scope"""
+    if dep.scope is None:
+        return "app"
+    return dep.scope

xpresso/applications.py

@@ -22,6 +22,7 @@
 from xpresso._utils.asgi import XpressoHTTPExtension, XpressoWebSocketExtension
 from xpresso._utils.overrides import DependencyOverrideManager
 from xpresso._utils.routing import visit_routes
+from xpresso._utils.scope_resolver import lifespan_scope_resolver
 from xpresso.dependencies._dependencies import BoundDependsMarker, Scopes
 from xpresso.exception_handlers import (
     ExcHandler,
@@ -102,6 +103,7 @@ async def lifespan_ctx(*_: typing.Any) -> typing.AsyncIterator[None]:
             placeholder = Dependant(lambda: None, scope="app")
             dep: "DependantBase[typing.Any]"
             executor = AsyncExecutor()
+
             async with self._container_state.enter_scope(
                 "app"
             ) as self._container_state:
@@ -122,6 +124,7 @@ async def lifespan_ctx(*_: typing.Any) -> typing.AsyncIterator[None]:
                         ],
                     ),
                     scopes=Scopes,
+                    scope_resolver=lifespan_scope_resolver,
                 )
                 try:
                     await self.container.execute_async(
@@ -140,13 +143,15 @@ async def lifespan_ctx(*_: typing.Any) -> typing.AsyncIterator[None]:
                         lifespan_deps.extend(
                             d for d in prepared.dag if d.scope == "app"
                         )
+
                     await self.container.execute_async(
                         self.container.solve(
                             JoinedDependant(
                                 placeholder,
                                 siblings=lifespan_deps,
                             ),
                             scopes=Scopes,
+                            scope_resolver=lifespan_scope_resolver,
                         ),
                         executor,
                         state=self._container_state,

xpresso/dependencies/_dependencies.py

@@ -8,7 +8,7 @@
 from xpresso._utils.typing import Literal
 
 Scope = Literal["app", "connection", "endpoint"]
-Scopes: typing.Tuple[Literal["app"], Literal["connection"], Literal["endpoint"]] = (
+Scopes = (
     "app",
     "connection",
     "endpoint",
@@ -44,7 +44,7 @@ def Depends(
     use_cache: bool = True,
     wire: bool = True,
     sync_to_thread: bool = False,
-    scope: Scope = "connection",
+    scope: typing.Optional[Scope] = None,
 ) -> typing.Any:
     return DependsMarker(
         call=call,
@@ -68,7 +68,7 @@ def __init__(
         use_cache: bool = True,
         wire: bool = True,
         sync_to_thread: bool = True,
-        scope: Scope = "connection",
+        scope: typing.Optional[Scope] = None,
     ) -> None:
         super().__init__(
             call=call,
@@ -98,7 +98,7 @@ class Injectable(InjectableBase):
     def __init_subclass__(
         cls,
         call: typing.Optional[DependencyProvider] = None,
-        scope: Scope = "connection",
+        scope: typing.Optional[Scope] = None,
         use_cache: bool = True,
         **kwargs: typing.Any,
     ) -> None:

xpresso/routing/operation.py

@@ -16,6 +16,7 @@
 import xpresso.openapi.models as openapi_models
 from xpresso._utils.asgi import XpressoHTTPExtension
 from xpresso._utils.endpoint_dependant import Endpoint, EndpointDependant
+from xpresso._utils.scope_resolver import endpoint_scope_resolver
 from xpresso.dependencies._dependencies import BoundDependsMarker, Scopes
 from xpresso.encoders import Encoder, JsonableEncoder
 from xpresso.responses import ResponseSpec, ResponseStatusCode, TypeUnset
@@ -164,6 +165,7 @@ def prepare(
                 siblings=[*dependencies, *self.dependencies],
             ),
             scopes=Scopes,
+            scope_resolver=endpoint_scope_resolver,
         )
         executor: SupportsAsyncExecutor
         if self._execute_dependencies_concurrently:

xpresso/routing/websockets.py

@@ -14,6 +14,7 @@
 
 from xpresso._utils.asgi import XpressoWebSocketExtension
 from xpresso._utils.endpoint_dependant import Endpoint, EndpointDependant
+from xpresso._utils.scope_resolver import endpoint_scope_resolver
 from xpresso.dependencies._dependencies import BoundDependsMarker, Scopes
 
 
@@ -94,6 +95,7 @@ def prepare(
                 siblings=[*dependencies, *self.dependencies],
             ),
             scopes=Scopes,
+            scope_resolver=endpoint_scope_resolver,
         )
         executor: SupportsAsyncExecutor
         if self.execute_dependencies_concurrently: