add test

tests/test_gateway.py

@@ -184,6 +184,41 @@ async def test_gateway_startup_failure(
     assert zha_gateway.shutdown.await_count == 1
 
 
+@pytest.mark.parametrize(("enabled", "await_count"), [(True, 1), (False, 0)])
+async def test_mains_devices_startup_polling_config(
+    zha_data: ZHAData,
+    zigpy_app_controller: ControllerApplication,
+    enabled: bool,
+    await_count: int,
+) -> None:
+    """Test mains powered device startup polling config is respected."""
+
+    with (
+        patch(
+            "bellows.zigbee.application.ControllerApplication.new",
+            return_value=zigpy_app_controller,
+        ),
+        patch(
+            "bellows.zigbee.application.ControllerApplication",
+            return_value=zigpy_app_controller,
+        ),
+    ):
+        zha_data.config.device_options.allow_mains_startup_polling = enabled
+        zha_gateway = await Gateway.async_from_config(zha_data)
+        zha_gateway.async_fetch_updated_state_mains = AsyncMock(
+            wraps=zha_gateway.async_fetch_updated_state_mains
+        )
+        await zha_gateway.async_initialize()
+        await zha_gateway.async_block_till_done()
+        await zha_gateway.async_initialize_devices_and_entities()
+        await zha_gateway.async_block_till_done()
+
+        assert zha_gateway.async_fetch_updated_state_mains.await_count == await_count
+
+        await zha_gateway.shutdown()
+        await zha_gateway.async_block_till_done()
+
+
 async def test_gateway_group_methods(
     zha_gateway: Gateway,
     device_light_1,  # pylint: disable=redefined-outer-name