From f527fd0947aa0b8d30374adbe8ec7b6f17db92af Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@koston.org>
Date: Tue, 9 Apr 2024 11:11:22 -1000
Subject: [PATCH] Improve error reporting when an integration tries to create a
 task in a thread (#115307)

---
 homeassistant/util/async_.py | 20 +++++++---
 tests/util/test_async.py     | 72 ++++++++++++++++++++++++++++++++++++
 2 files changed, 86 insertions(+), 6 deletions(-)

diff --git a/homeassistant/util/async_.py b/homeassistant/util/async_.py
index 5ca19296b41..0cf9fc992c5 100644
--- a/homeassistant/util/async_.py
+++ b/homeassistant/util/async_.py
@@ -24,12 +24,20 @@ def create_eager_task(
     loop: AbstractEventLoop | None = None,
 ) -> Task[_T]:
     """Create a task from a coroutine and schedule it to run immediately."""
-    return Task(
-        coro,
-        loop=loop or get_running_loop(),
-        name=name,
-        eager_start=True,
-    )
+    if not loop:
+        try:
+            loop = get_running_loop()
+        except RuntimeError:
+            # If there is no running loop, create_eager_task is being called from
+            # the wrong thread.
+            # Late import to avoid circular dependencies
+            # pylint: disable-next=import-outside-toplevel
+            from homeassistant.helpers import frame
+
+            frame.report("attempted to create an asyncio task from a thread")
+            raise
+
+    return Task(coro, loop=loop, name=name, eager_start=True)
 
 
 def cancelling(task: Future[Any]) -> bool:
diff --git a/tests/util/test_async.py b/tests/util/test_async.py
index d0131df88ee..157becc4b01 100644
--- a/tests/util/test_async.py
+++ b/tests/util/test_async.py
@@ -9,6 +9,8 @@ import pytest
 from homeassistant.core import HomeAssistant
 from homeassistant.util import async_ as hasync
 
+from tests.common import extract_stack_to_frame
+
 
 @patch("concurrent.futures.Future")
 @patch("threading.get_ident")
@@ -123,3 +125,73 @@ async def test_create_eager_task_312(hass: HomeAssistant) -> None:
     assert events == ["eager", "normal"]
     await task1
     await task2
+
+
+async def test_create_eager_task_from_thread(hass: HomeAssistant) -> None:
+    """Test we report trying to create an eager task from a thread."""
+
+    def create_task():
+        hasync.create_eager_task(asyncio.sleep(0))
+
+    with pytest.raises(
+        RuntimeError,
+        match=(
+            "Detected code that attempted to create an asyncio task from a thread. Please report this issue."
+        ),
+    ):
+        await hass.async_add_executor_job(create_task)
+
+
+async def test_create_eager_task_from_thread_in_integration(
+    hass: HomeAssistant, caplog: pytest.LogCaptureFixture
+) -> None:
+    """Test we report trying to create an eager task from a thread."""
+
+    def create_task():
+        hasync.create_eager_task(asyncio.sleep(0))
+
+    frames = extract_stack_to_frame(
+        [
+            Mock(
+                filename="/home/paulus/homeassistant/core.py",
+                lineno="23",
+                line="do_something()",
+            ),
+            Mock(
+                filename="/home/paulus/homeassistant/components/hue/light.py",
+                lineno="23",
+                line="self.light.is_on",
+            ),
+            Mock(
+                filename="/home/paulus/aiohue/lights.py",
+                lineno="2",
+                line="something()",
+            ),
+        ]
+    )
+    with (
+        pytest.raises(RuntimeError, match="no running event loop"),
+        patch(
+            "homeassistant.helpers.frame.linecache.getline",
+            return_value="self.light.is_on",
+        ),
+        patch(
+            "homeassistant.util.loop._get_line_from_cache",
+            return_value="mock_line",
+        ),
+        patch(
+            "homeassistant.util.loop.get_current_frame",
+            return_value=frames,
+        ),
+        patch(
+            "homeassistant.helpers.frame.get_current_frame",
+            return_value=frames,
+        ),
+    ):
+        await hass.async_add_executor_job(create_task)
+
+    assert (
+        "Detected that integration 'hue' attempted to create an asyncio task "
+        "from a thread at homeassistant/components/hue/light.py, line 23: "
+        "self.light.is_on"
+    ) in caplog.text