Add the ability to create Debouncer tasks as background tasks (#113128)

* Add the ability to Debouncer tasks in the background

This is a more general solution as a followup to
https://github.com/home-assistant/core/pull/112652#discussion_r1517159607

* Add the ability to Debouncer tasks in the background

This is a more general solution as a followup to
https://github.com/home-assistant/core/pull/112652#discussion_r1517159607

* fix

homeassistant/helpers/debounce.py

@@ -23,6 +23,7 @@ class Debouncer(Generic[_R_co]):
         cooldown: float,
         immediate: bool,
         function: Callable[[], _R_co] | None = None,
+        background: bool = False,
     ) -> None:
         """Initialize debounce.
 
@@ -38,6 +39,7 @@ class Debouncer(Generic[_R_co]):
         self._timer_task: asyncio.TimerHandle | None = None
         self._execute_at_end_of_timer: bool = False
         self._execute_lock = asyncio.Lock()
+        self._background = background
         self._job: HassJob[[], _R_co] | None = (
             None
             if function is None
@@ -109,7 +111,9 @@ class Debouncer(Generic[_R_co]):
 
             assert self._job is not None
             try:
-                if task := self.hass.async_run_hass_job(self._job):
+                if task := self.hass.async_run_hass_job(
+                    self._job, background=self._background
+                ):
                     await task
             finally:
                 self._schedule_timer()
@@ -130,7 +134,9 @@ class Debouncer(Generic[_R_co]):
                 return
 
             try:
-                if task := self.hass.async_run_hass_job(self._job):
+                if task := self.hass.async_run_hass_job(
+                    self._job, background=self._background
+                ):
                     await task
             except Exception:  # pylint: disable=broad-except
                 self.logger.exception("Unexpected exception from %s", self.function)
@@ -157,13 +163,18 @@ class Debouncer(Generic[_R_co]):
     def _on_debounce(self) -> None:
         """Create job task, but only if pending."""
         self._timer_task = None
-        if self._execute_at_end_of_timer:
-            self._execute_at_end_of_timer = False
+        if not self._execute_at_end_of_timer:
+            return
+        self._execute_at_end_of_timer = False
+        name = f"debouncer {self._job} finish cooldown={self.cooldown}, immediate={self.immediate}"
+        if not self._background:
             self.hass.async_create_task(
-                self._handle_timer_finish(),
-                f"debouncer {self._job} finish cooldown={self.cooldown}, immediate={self.immediate}",
-                eager_start=True,
+                self._handle_timer_finish(), name, eager_start=True
             )
+            return
+        self.hass.async_create_background_task(
+            self._handle_timer_finish(), name, eager_start=True
+        )
 
     @callback
     def _schedule_timer(self) -> None:

tests/helpers/test_debounce.py

@@ -497,3 +497,35 @@ async def test_shutdown(hass: HomeAssistant, caplog: pytest.LogCaptureFixture) -
 
     assert len(calls) == 1
     assert debouncer._timer_task is None
+
+
+async def test_background(
+    hass: HomeAssistant, caplog: pytest.LogCaptureFixture
+) -> None:
+    """Test background tasks are created when background is True."""
+    calls = []
+
+    async def _func() -> None:
+        await asyncio.sleep(0.1)
+        calls.append(None)
+
+    debouncer = debounce.Debouncer(
+        hass, _LOGGER, cooldown=0.05, immediate=True, function=_func, background=True
+    )
+
+    await debouncer.async_call()
+    assert len(calls) == 1
+
+    debouncer.async_schedule_call()
+    assert len(calls) == 1
+
+    async_fire_time_changed(hass, utcnow() + timedelta(seconds=1))
+    await hass.async_block_till_done(wait_background_tasks=False)
+    assert len(calls) == 1
+
+    await hass.async_block_till_done(wait_background_tasks=True)
+    assert len(calls) == 2
+
+    async_fire_time_changed(hass, utcnow() + timedelta(seconds=1))
+    await hass.async_block_till_done(wait_background_tasks=False)
+    assert len(calls) == 2