Avoid interacting with class/fn objects during registration.

test/integration/flask/services/factories.py

@@ -0,0 +1,12 @@
+from flask import g
+from wireup import service
+
+
+class FlaskG:
+    def __init__(self, g):
+        self.g = g
+
+
+@service
+def thing() -> FlaskG:
+    return FlaskG(g)

test/integration/test_flask_integration.py → test/integration/flask/test_flask_integration.py

@@ -1,9 +1,11 @@
 import unittest
 from dataclasses import dataclass
 from test.fixtures import FooBar, FooBase
+from test.integration.flask import services
+from test.integration.flask.services.factories import FlaskG
 from test.unit.services.no_annotations.random.random_service import RandomService
 
-from flask import Flask
+from flask import Flask, g
 from typing_extensions import Annotated
 from wireup import DependencyContainer, Inject, ParameterBag
 from wireup.integration.flask_integration import wireup_init_flask_integration
@@ -69,7 +71,7 @@ def target(foo: FooBase):
 
         self.container.abstract(FooBase)
         self.container.register(FooBar)
-        wireup_init_flask_integration(self.app, dependency_container=self.container, service_modules=[])
+        wireup_init_flask_integration(self.app, dependency_container=self.container, service_modules=[services])
 
         res = self.client.get("/intf")
         self.assertEqual(res.status_code, 200)
@@ -90,3 +92,16 @@ def get_environment(foo: Foo):
 
         self.assertEqual(res.status_code, 200)
         self.assertEqual(res.json, {"test": True})
+
+    def test_does_not_interact_with_flask_g_when_registering(self):
+        @self.app.get("/")
+        def get_environment(foo: FlaskG):
+            foo.g.value = 1
+
+            return {"g": g.value}
+
+        wireup_init_flask_integration(self.app, dependency_container=self.container, service_modules=[services])
+        res = self.client.get("/")
+
+        self.assertEqual(res.status_code, 200)
+        self.assertEqual(res.json, {"g": 1})

wireup/import_util.py

@@ -4,6 +4,7 @@
 import importlib
 import inspect
 import re
+import types
 import warnings
 from pathlib import Path
 from typing import TYPE_CHECKING, Any
@@ -44,8 +45,14 @@ def _register_services(dependency_container: DependencyContainer, service_module
     abstract_registrations: set[type[Any]] = set()
     service_registrations: list[ServiceDeclaration] = []
 
+    def _is_valid_wireup_target(obj: Any) -> bool:
+        # Check that the hasattr call is only made on user defined functions and classes.
+        # This is so that it avoids interacting with proxies and things such as flask.g when imported.
+        # "from flask import g" would cause a hasattr call to g outside of app context.
+        return (isinstance(obj, types.FunctionType) or inspect.isclass(obj)) and hasattr(obj, "__wireup_registration__")
+
     for module in service_modules:
-        for cls in _find_objects_in_module(module, predicate=lambda obj: hasattr(obj, "__wireup_registration__")):
+        for cls in _find_objects_in_module(module, predicate=_is_valid_wireup_target):
             reg = getattr(cls, "__wireup_registration__", None)
 
             if isinstance(reg, ServiceDeclaration):