From 467c4f4f8521c29bb3851451d578267b1e37741f Mon Sep 17 00:00:00 2001
From: CoolCat467 <52022020+CoolCat467@users.noreply.github.com>
Date: Sun, 3 Sep 2023 00:12:55 -0500
Subject: [PATCH 1/4] Start fixing type errors

---
 trio/_core/_run.py | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/trio/_core/_run.py b/trio/_core/_run.py
index c5c16803b0..0ed5f78322 100644
--- a/trio/_core/_run.py
+++ b/trio/_core/_run.py
@@ -200,8 +200,7 @@ def collapse_exception_group(
         )
         return exceptions[0]
     elif modified:
-        # derive() returns Any for some reason.
-        return excgroup.derive(exceptions)  # type: ignore[no-any-return]
+        return excgroup.derive(exceptions)
     else:
         return excgroup
 

From 90bbcf17891650ae90f493aa9aa02b3b347b8930 Mon Sep 17 00:00:00 2001
From: CoolCat467 <52022020+CoolCat467@users.noreply.github.com>
Date: Sun, 3 Sep 2023 00:15:17 -0500
Subject: [PATCH 2/4] Fix formatting

---
 trio/_threads.py | 1 -
 1 file changed, 1 deletion(-)

diff --git a/trio/_threads.py b/trio/_threads.py
index 2780fb6446..24905cfbde 100644
--- a/trio/_threads.py
+++ b/trio/_threads.py
@@ -409,7 +409,6 @@ def callback(
         fn: Callable[..., RetT],
         args: tuple[object, ...],
     ) -> None:
-
         @disable_ki_protection
         def unprotected_fn() -> RetT:
             ret = fn(*args)

From 556fea4ebba3ff6ddfe3f0cbad6faa6ac4925ad7 Mon Sep 17 00:00:00 2001
From: CoolCat467 <52022020+CoolCat467@users.noreply.github.com>
Date: Sun, 3 Sep 2023 00:21:13 -0500
Subject: [PATCH 3/4] Fix type annotations

---
 trio/_core/_run.py            | 9 +++++++--
 trio/_core/_tests/test_run.py | 2 +-
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/trio/_core/_run.py b/trio/_core/_run.py
index 0ed5f78322..c51ffd6af2 100644
--- a/trio/_core/_run.py
+++ b/trio/_core/_run.py
@@ -2357,7 +2357,9 @@ def my_done_callback(run_outcome):
     # spawn_system_task. We don't actually run any user code during
     # this time, so it shouldn't be possible to get an exception here,
     # except for a TrioInternalError.
-    next_send = None
+    next_send: EventResult = cast(
+        EventResult, None
+    )  # First iteration must be `None`, every iteration after that is EventResult
     for tick in range(5):  # expected need is 2 iterations + leave some wiggle room
         if runner.system_nursery is not None:
             # We're initialized enough to switch to async guest ticks
@@ -2378,7 +2380,10 @@ def my_done_callback(run_outcome):
         # IOManager.get_events() if no I/O was waiting, which is
         # platform-dependent. We don't actually check for I/O during
         # this init phase because no one should be expecting any yet.
-        next_send = 0 if sys.platform == "win32" else ()
+        if sys.platform == "win32":
+            next_send = 0
+        else:
+            next_send = []
     else:  # pragma: no cover
         guest_state.unrolled_run_gen.throw(
             TrioInternalError(
diff --git a/trio/_core/_tests/test_run.py b/trio/_core/_tests/test_run.py
index 0b15b606fb..5c45cf828f 100644
--- a/trio/_core/_tests/test_run.py
+++ b/trio/_core/_tests/test_run.py
@@ -2066,7 +2066,7 @@ def check_function_returning_coroutine() -> Awaitable[object]:
         sniffio.current_async_library()
 
     @contextmanager
-    def alternate_sniffio_library():
+    def alternate_sniffio_library() -> Generator[None, None, None]:
         prev_token = sniffio.current_async_library_cvar.set("nullio")
         prev_library, sniffio.thread_local.name = sniffio.thread_local.name, "nullio"
         try:

From dacd4b3ff415938a6a7de1fb8a0bcd9221be6a61 Mon Sep 17 00:00:00 2001
From: CoolCat467 <52022020+CoolCat467@users.noreply.github.com>
Date: Sun, 3 Sep 2023 00:50:21 -0500
Subject: [PATCH 4/4] Explicit typing not required after cast

---
 trio/_core/_run.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/trio/_core/_run.py b/trio/_core/_run.py
index c51ffd6af2..b2f3a65ddd 100644
--- a/trio/_core/_run.py
+++ b/trio/_core/_run.py
@@ -2357,7 +2357,7 @@ def my_done_callback(run_outcome):
     # spawn_system_task. We don't actually run any user code during
     # this time, so it shouldn't be possible to get an exception here,
     # except for a TrioInternalError.
-    next_send: EventResult = cast(
+    next_send = cast(
         EventResult, None
     )  # First iteration must be `None`, every iteration after that is EventResult
     for tick in range(5):  # expected need is 2 iterations + leave some wiggle room