fix: restore static typing of inject.attr(Cls)

.github/workflows/tests.yaml

@@ -53,6 +53,21 @@ jobs:
 #        run: |
 #          tox -e lint-mypy
 
+  types:
+    name: "Type checking (public API)"
+    runs-on: ubuntu-24.04
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-python@v5
+        with:
+          python-version: "3.14"
+      - name: "Install tox"
+        run: |
+          pip install tox
+      - name: "Type checking (public API)"
+        run: |
+          tox -e lint-types
+
   tests:
     name: "Run unit tests"
     runs-on: ubuntu-24.04

pyproject.toml

@@ -97,7 +97,7 @@ defineConstant = { DEBUG = true }
 exclude = []
 executionEnvironments = []
 ignore = []
-include = ["src/inject", "tests"]
+include = ["src/inject", "tests", "typing_checks"]
 pythonPlatform = "Linux"
 pythonVersion = "3.11"
 reportMissingImports = true
@@ -275,6 +275,7 @@ env_list = [
   "fmt-py",
   "fmt-toml",
   "lint-py",
+  "lint-types",
   #"lint-mypy",  # TODO(pyctrl): make it green & uncomment
   "lint-toml",
   "lint-yaml",
@@ -289,6 +290,7 @@ fmt = [
 ]
 lint = [
   "lint-py",
+  "lint-types",
   #"lint-mypy",  # TODO(pyctrl): make it green & uncomment
   "lint-toml",
   "lint-yaml",
@@ -325,6 +327,18 @@ commands = [
   ],
 ]
 
+[tool.tox.env.lint-types]
+description = "Type-check the public-API typing guards"
+deps = ["mypy"]
+commands = [
+  [
+    "mypy",
+    { replace = "posargs", default = [
+      "typing_checks",
+    ], extend = true },
+  ],
+]
+
 [tool.tox.env.lint-mypy]
 description = "Type checking"
 deps = ["mypy"]

src/inject/__init__.py

@@ -614,11 +614,11 @@ def attr() -> Injectable: ...
 
 
 @t.overload
-def attr(cls: t.Hashable) -> Injectable: ...
+def attr(cls: type[T]) -> T: ...
 
 
 @t.overload
-def attr(cls: type[T]) -> T: ...
+def attr(cls: t.Hashable) -> Injectable: ...
 
 
 def attr(cls=_MISSING):

typing_checks/attr.py

@@ -0,0 +1,17 @@
+"""Static-typing regression guard for ``inject.attr``."""
+
+from typing_extensions import assert_type
+
+import inject
+
+
+class _Service:
+    pass
+
+
+class _Repository:
+    pass
+
+
+assert_type(inject.attr(_Service), _Service)
+assert_type(inject.attr(_Repository), _Repository)