From b39c83efd23db5190ebf93bf0bc34ac6858af528 Mon Sep 17 00:00:00 2001
From: Will Moss <wbmoss@gmail.com>
Date: Fri, 27 Mar 2026 11:12:55 -0700
Subject: [PATCH] Handle Oauth2 ImplementationUnavailableError in google
 (#166647)

Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>
---
 homeassistant/components/google/__init__.py  | 17 +++++++++++++----
 homeassistant/components/google/strings.json |  5 +++++
 tests/components/google/test_init.py         | 20 ++++++++++++++++++++
 3 files changed, 38 insertions(+), 4 deletions(-)

diff --git a/homeassistant/components/google/__init__.py b/homeassistant/components/google/__init__.py
index 0f8be7a52e9..edc7dc50967 100644
--- a/homeassistant/components/google/__init__.py
+++ b/homeassistant/components/google/__init__.py
@@ -24,6 +24,9 @@ from homeassistant.core import HomeAssistant
 from homeassistant.exceptions import ConfigEntryAuthFailed, ConfigEntryNotReady
 from homeassistant.helpers import config_entry_oauth2_flow, config_validation as cv
 from homeassistant.helpers.aiohttp_client import async_get_clientsession
+from homeassistant.helpers.config_entry_oauth2_flow import (
+    ImplementationUnavailableError,
+)
 from homeassistant.helpers.entity import generate_entity_id
 
 from .api import ApiAuthImpl, get_feature_access
@@ -88,11 +91,17 @@ async def async_setup_entry(hass: HomeAssistant, entry: GoogleConfigEntry) -> bo
         _LOGGER.error("Configuration error in %s: %s", YAML_DEVICES, str(err))
         return False
 
-    implementation = (
-        await config_entry_oauth2_flow.async_get_config_entry_implementation(
-            hass, entry
+    try:
+        implementation = (
+            await config_entry_oauth2_flow.async_get_config_entry_implementation(
+                hass, entry
+            )
         )
-    )
+    except ImplementationUnavailableError as err:
+        raise ConfigEntryNotReady(
+            translation_domain=DOMAIN,
+            translation_key="oauth2_implementation_unavailable",
+        ) from err
     session = config_entry_oauth2_flow.OAuth2Session(hass, entry, implementation)
     # Force a token refresh to fix a bug where tokens were persisted with
     # expires_in (relative time delta) and expires_at (absolute time) swapped.
diff --git a/homeassistant/components/google/strings.json b/homeassistant/components/google/strings.json
index 2660848f8f2..91fd097ef0d 100644
--- a/homeassistant/components/google/strings.json
+++ b/homeassistant/components/google/strings.json
@@ -57,6 +57,11 @@
       }
     }
   },
+  "exceptions": {
+    "oauth2_implementation_unavailable": {
+      "message": "[%key:common::exceptions::oauth2_implementation_unavailable::message%]"
+    }
+  },
   "options": {
     "step": {
       "init": {
diff --git a/tests/components/google/test_init.py b/tests/components/google/test_init.py
index 02f9e1b48bd..ee272c54c99 100644
--- a/tests/components/google/test_init.py
+++ b/tests/components/google/test_init.py
@@ -21,6 +21,9 @@ from homeassistant.config_entries import ConfigEntryState
 from homeassistant.const import ATTR_FRIENDLY_NAME, STATE_OFF
 from homeassistant.core import HomeAssistant, State
 from homeassistant.exceptions import HomeAssistantError, ServiceNotSupported
+from homeassistant.helpers.config_entry_oauth2_flow import (
+    ImplementationUnavailableError,
+)
 from homeassistant.setup import async_setup_component
 from homeassistant.util.dt import UTC, utcnow
 
@@ -902,3 +905,20 @@ async def test_remove_entry(
 
     assert await hass.config_entries.async_remove(entry.entry_id)
     assert entry.state is ConfigEntryState.NOT_LOADED
+
+
+async def test_oauth_implementation_not_available(
+    hass: HomeAssistant,
+    config_entry: MockConfigEntry,
+) -> None:
+    """Test that unavailable OAuth implementation raises ConfigEntryNotReady."""
+    config_entry.add_to_hass(hass)
+
+    with patch(
+        "homeassistant.helpers.config_entry_oauth2_flow.async_get_config_entry_implementation",
+        side_effect=ImplementationUnavailableError,
+    ):
+        await hass.config_entries.async_setup(config_entry.entry_id)
+        await hass.async_block_till_done()
+
+    assert config_entry.state is ConfigEntryState.SETUP_RETRY