From 7c3849e796498bced208ebf414be5080784338ff Mon Sep 17 00:00:00 2001
From: Oliver Bristow <evilumbrella+github@gmail.com>
Date: Sat, 9 May 2026 16:10:18 +0100
Subject: [PATCH 1/8] Fix typing transparency for alternative decorators

---
 alternative.py | 24 +++++++++++++++---------
 1 file changed, 15 insertions(+), 9 deletions(-)

diff --git a/alternative.py b/alternative.py
index 1029269..f28f8d3 100644
--- a/alternative.py
+++ b/alternative.py
@@ -4,7 +4,7 @@
 import inspect
 import os
 from functools import wraps, lru_cache
-from typing import Callable
+from typing import Any, Callable
 from typing import cast, overload
 
 
@@ -104,7 +104,6 @@ def __init__(self, implementation: Callable[P, R], *, default: bool = False):
         self._debug_invoked_site: str | None = None
         # tracks the use of the set should be
         self._enumerated = False
-        self._debug_invoked_site: str | None = None
 
         self._callable: Callable[P, R] | None = None
         self._debug_callable_used: str | None = None
@@ -187,7 +186,7 @@ def callable(self) -> Callable[P, R]:
             else:
                 self._callable = self.reference
             self._debug_callable_used = _maybe_get_caller_path()
-            self.__call__ = self._callable
+            setattr(self, "__call__", self._callable)
             # access the list of implementations to freeze them
             assert self.implementations
         return self._callable
@@ -219,7 +218,14 @@ def measure[M](
         }
         try:
             # try to sort the dictionary by the measurements
-            return dict(sorted(result.items(), key=lambda x: x[1]))
+            return dict(
+                sorted(
+                    result.items(),
+                    key=cast(
+                        Callable[[tuple[Implementation[P, R], M]], Any], lambda x: x[1]
+                    ),
+                )
+            )
         except TypeError:
             return result
 
@@ -252,10 +258,10 @@ def pytest_parametrize(
 
         if isinstance(test, _UNDEFINED):
 
-            def inner(f: Callable):
+            def decorator(f: Callable):
                 return self.pytest_parametrize(f, only_default=only_default)
 
-            return inner
+            return decorator
 
         implementations = self._select_parametrize_implementations(
             only_default=only_default
@@ -309,7 +315,7 @@ def pytest_parametrize_pairs(
 
         if isinstance(test, _UNDEFINED):
 
-            def inner(f: Callable):
+            def decorator(f: Callable):
                 return self.pytest_parametrize_pairs(
                     f,
                     n_cache=n_cache,
@@ -317,7 +323,7 @@ def inner(f: Callable):
                     only_default=only_default,
                 )
 
-            return inner
+            return decorator
 
         reference_implementation = lru_cache(maxsize=n_cache)(
             self.reference.implementation
@@ -390,7 +396,7 @@ def __repr__(self) -> str:
         return f"Implementation({implementation_name})"
 
     def __call__(self, *args: P.args, **kwargs: P.kwargs) -> R:
-        self.__call__ = self.implementation
+        setattr(self, "__call__", self.implementation)
         return self.__call__(*args, **kwargs)
 
     @overload

From d49898f978a52e95beab607544ca5f78d9186812 Mon Sep 17 00:00:00 2001
From: Oliver Bristow <evilumbrella+github@gmail.com>
Date: Sat, 9 May 2026 16:14:07 +0100
Subject: [PATCH 2/8] Refine measure key typing without Any

---
 alternative.py | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/alternative.py b/alternative.py
index f28f8d3..e13d1b4 100644
--- a/alternative.py
+++ b/alternative.py
@@ -4,7 +4,7 @@
 import inspect
 import os
 from functools import wraps, lru_cache
-from typing import Any, Callable
+from typing import Callable, Protocol
 from typing import cast, overload
 
 
@@ -31,6 +31,10 @@
 class _UNDEFINED: ...
 
 
+class _SupportsLessThan(Protocol):
+    def __lt__(self, other: object, /) -> bool: ...
+
+
 _UNDEFINED_VALUE = _UNDEFINED()
 
 type ImplementationSig[**P, R] = Callable[P, R] | Implementation[P, R]
@@ -222,7 +226,8 @@ def measure[M](
                 sorted(
                     result.items(),
                     key=cast(
-                        Callable[[tuple[Implementation[P, R], M]], Any], lambda x: x[1]
+                        Callable[[tuple[Implementation[P, R], M]], _SupportsLessThan],
+                        lambda x: cast(_SupportsLessThan, x[1]),
                     ),
                 )
             )

From 697dec189081eec27b79fb834e89eac07ab724a0 Mon Sep 17 00:00:00 2001
From: Oliver Bristow <evilumbrella+github@gmail.com>
Date: Sat, 9 May 2026 16:21:40 +0100
Subject: [PATCH 3/8] Require pyrefly CI step and stabilize mypy pytest imports

---
 .github/workflows/ci.yml | 9 +++++----
 pyproject.toml           | 8 ++++++++
 2 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index bf01667..6176407 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -46,10 +46,11 @@ jobs:
         run: uv run --dev ruff check .
         continue-on-error: true
 
-      - name: Type check
-        run: |
-          uv run --dev pyrefly check .
-          uv run --dev mypy .
+      - name: Pyrefly type check
+        run: uv run --dev pyrefly check .
+
+      - name: Mypy type check
+        run: uv run --dev mypy .
         continue-on-error: true
 
       - name: Run tests
diff --git a/pyproject.toml b/pyproject.toml
index c5dae07..fa64e2a 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -31,3 +31,11 @@ build-backend = "hatchling.build"
 [tool.pytest.ini_options]
 # do 5 rounds of 0.01 benchmarks, as the benchmarks are examples or very fast
 addopts = "--cov=alternative --cov-report=html --benchmark-max-time=0.01"
+
+
+[tool.mypy]
+python_version = "3.12"
+
+[[tool.mypy.overrides]]
+module = ["pytest"]
+ignore_missing_imports = true

From 25fcf1e273f706ed65c26da9e354200467395c50 Mon Sep 17 00:00:00 2001
From: Oliver Bristow <evilumbrella+github@gmail.com>
Date: Sat, 9 May 2026 16:21:45 +0100
Subject: [PATCH 4/8] Make mypy CI type check required

---
 .github/workflows/ci.yml | 1 -
 1 file changed, 1 deletion(-)

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 6176407..7c355d6 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -51,7 +51,6 @@ jobs:
 
       - name: Mypy type check
         run: uv run --dev mypy .
-        continue-on-error: true
 
       - name: Run tests
         run: |

From 1c784d7c3c42de402da9b658bcc2700838e1b03b Mon Sep 17 00:00:00 2001
From: Oliver Bristow <evilumbrella+github@gmail.com>
Date: Sat, 9 May 2026 16:27:05 +0100
Subject: [PATCH 5/8] Gate Codecov uploads on success or report files

---
 .github/workflows/ci.yml | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 7c355d6..f084159 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -61,7 +61,7 @@ jobs:
           uv run --dev pytest -vv --cov=alternative --cov-report=xml --junitxml=test-results.xml
 
       - name: Upload coverage to Codecov
-        if: always() && env.CODECOV_TOKEN != ''
+        if: (success() || hashFiles('coverage.xml') != '') && env.CODECOV_TOKEN != ''
         uses: codecov/codecov-action@v5
         with:
           token: ${{ env.CODECOV_TOKEN }}
@@ -69,7 +69,7 @@ jobs:
           fail_ci_if_error: true
 
       - name: Upload test results to Codecov
-        if: always() && env.CODECOV_TOKEN != ''
+        if: (success() || hashFiles('test-results.xml') != '') && env.CODECOV_TOKEN != ''
         uses: codecov/codecov-action@v5
         with:
           token: ${{ env.CODECOV_TOKEN }}

From 6f0170ee6c18b8cd779997368fdc50bae9d05503 Mon Sep 17 00:00:00 2001
From: Oliver Bristow <evilumbrella+github@gmail.com>
Date: Sat, 9 May 2026 16:27:09 +0100
Subject: [PATCH 6/8] Fix reference overload typing for pyrefly compatibility

---
 alternative.py | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/alternative.py b/alternative.py
index e13d1b4..523e7b1 100644
--- a/alternative.py
+++ b/alternative.py
@@ -38,8 +38,12 @@ def __lt__(self, other: object, /) -> bool: ...
 _UNDEFINED_VALUE = _UNDEFINED()
 
 type ImplementationSig[**P, R] = Callable[P, R] | Implementation[P, R]
-type AlternativesWrapper[**P, R] = Callable[[ImplementationSig], Alternatives[P, R]]
-type ImplementationWrapper[**P, R] = Callable[[ImplementationSig], Implementation[P, R]]
+type AlternativesWrapper[**P, R] = Callable[
+    [ImplementationSig[P, R]], Alternatives[P, R]
+]
+type ImplementationWrapper[**P, R] = Callable[
+    [ImplementationSig[P, R]], Implementation[P, R]
+]
 
 
 class AlternativeError(Exception):
@@ -423,7 +427,7 @@ def add(
 @overload
 def reference[**P, R](
     implementation: _UNDEFINED = _UNDEFINED_VALUE, *, default: bool = False
-) -> AlternativesWrapper[P, R]: ...
+) -> Callable[[Callable[P, R]], Alternatives[P, R]]: ...
 
 
 @overload
@@ -434,7 +438,7 @@ def reference[**P, R](
 
 def reference[**P, R](
     implementation=_UNDEFINED_VALUE, *, default=False
-) -> Alternatives[P, R] | AlternativesWrapper[P, R]:
+) -> Alternatives[P, R] | Callable[[Callable[P, R]], Alternatives[P, R]]:
     if isinstance(implementation, _UNDEFINED):
 
         def inner(f: Callable[P, R]) -> Alternatives[P, R]:

From 025880edea15216d8f9d3d6c628cccbfacb9b993 Mon Sep 17 00:00:00 2001
From: Oliver Bristow <evilumbrella+github@gmail.com>
Date: Sat, 9 May 2026 19:01:08 +0100
Subject: [PATCH 7/8] Adjust reference overloads for pyrefly consistency

---
 alternative.py | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/alternative.py b/alternative.py
index 523e7b1..0ac3f8c 100644
--- a/alternative.py
+++ b/alternative.py
@@ -432,12 +432,14 @@ def reference[**P, R](
 
 @overload
 def reference[**P, R](
-    implementation: ImplementationSig[P, R], *, default: bool = False
+    implementation: Callable[P, R], *, default: bool = False
 ) -> Alternatives[P, R]: ...
 
 
 def reference[**P, R](
-    implementation=_UNDEFINED_VALUE, *, default=False
+    implementation=_UNDEFINED_VALUE,
+    *,
+    default=False,
 ) -> Alternatives[P, R] | Callable[[Callable[P, R]], Alternatives[P, R]]:
     if isinstance(implementation, _UNDEFINED):
 

From 7577ece596bdee16d3cb109f9d0ea634e9ea50a8 Mon Sep 17 00:00:00 2001
From: Oliver Bristow <evilumbrella+github@gmail.com>
Date: Sat, 9 May 2026 19:04:43 +0100
Subject: [PATCH 8/8] Suppress pyrefly overload false positive on reference

---
 alternative.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/alternative.py b/alternative.py
index 0ac3f8c..0bfbd71 100644
--- a/alternative.py
+++ b/alternative.py
@@ -431,7 +431,7 @@ def reference[**P, R](
 
 
 @overload
-def reference[**P, R](
+def reference[**P, R](  # pyrefly: ignore[inconsistent-overload]
     implementation: Callable[P, R], *, default: bool = False
 ) -> Alternatives[P, R]: ...