From c585817e6719ae019468924f88580920ccbfdc05 Mon Sep 17 00:00:00 2001
From: epenet <6771947+epenet@users.noreply.github.com>
Date: Tue, 8 Nov 2022 11:18:58 +0100
Subject: [PATCH] Adjust REST schema validation (#81723)

fixes undefined
---
 homeassistant/components/rest/schema.py |  9 ++++++++-
 tests/components/rest/test_init.py      | 20 +++++++++++++++++++-
 2 files changed, 27 insertions(+), 2 deletions(-)

diff --git a/homeassistant/components/rest/schema.py b/homeassistant/components/rest/schema.py
index f881dc8b028..d124ce5789c 100644
--- a/homeassistant/components/rest/schema.py
+++ b/homeassistant/components/rest/schema.py
@@ -89,6 +89,13 @@ COMBINED_SCHEMA = vol.Schema(
 )
 
 CONFIG_SCHEMA = vol.Schema(
-    {DOMAIN: vol.All(cv.ensure_list, [COMBINED_SCHEMA])},
+    {
+        DOMAIN: vol.All(
+            # convert empty dict to empty list
+            lambda x: [] if x == {} else x,
+            cv.ensure_list,
+            [COMBINED_SCHEMA],
+        )
+    },
     extra=vol.ALLOW_EXTRA,
 )
diff --git a/tests/components/rest/test_init.py b/tests/components/rest/test_init.py
index 6dd2650c25c..08d538fd163 100644
--- a/tests/components/rest/test_init.py
+++ b/tests/components/rest/test_init.py
@@ -19,7 +19,11 @@ from homeassistant.core import HomeAssistant
 from homeassistant.setup import async_setup_component
 from homeassistant.util.dt import utcnow
 
-from tests.common import async_fire_time_changed, get_fixture_path
+from tests.common import (
+    assert_setup_component,
+    async_fire_time_changed,
+    get_fixture_path,
+)
 
 
 @respx.mock
@@ -400,3 +404,17 @@ async def test_multiple_rest_endpoints(hass: HomeAssistant) -> None:
     assert hass.states.get("sensor.json_date_time").state == "07:11:08 PM"
     assert hass.states.get("sensor.json_time").state == "07:11:39 PM"
     assert hass.states.get("binary_sensor.binary_sensor").state == "on"
+
+
+async def test_empty_config(hass: HomeAssistant) -> None:
+    """Test setup with empty configuration.
+
+    For example (with rest.yaml an empty file):
+        rest: !include rest.yaml
+    """
+    assert await async_setup_component(
+        hass,
+        DOMAIN,
+        {DOMAIN: {}},
+    )
+    assert_setup_component(0, DOMAIN)