Fix/bug in app handler (#188)

* use reload instead of init to avoid losing apps

* cache original dev_mode value, do not change

* change to debug log level

* Update tests/test_apps.py

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

* add validation aliases for autodetect_apps, remove changelog entry

* add changelog entry for fix

* Update src/hassette/config/helpers.py

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

* remove inner function

* bump version and update changelog

---------

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: NodeJSmith

CHANGELOG.md

@@ -7,8 +7,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## Unreleased
 
+## [0.15.5] - 2025-11-14
+
 ### Changed
-- **Breaking:** Rename all `auto_detect` values to `autodetect` (e.g. `auto_detect_apps` -> `autodetect_apps`)
 - Update `HassetteConfig` defaults to differ if in dev mode
   - Generally speaking, values are extended (e.g. timeouts) and more permissive (e.g. `allow_startup_if_app_precheck_fails = true` in dev mode)
 - Moved `AppManifest` and `HassetteTomlConfigSettingsSource` to `classes.py`
@@ -17,6 +18,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Bumped version of `uv` in `mise.toml`, docker image, and build backend
 - Converted docs to mkdocs instead of sphinx
 
+### Fixed
+- Fixed bug in AppHandler where all apps would be lost when `handle_changes` was called, due to improper reloading of configuration
+  - Now uses `HassetteConfig.reload()` to reload config instead of re-initializing the class
+
 ## [0.15.4] - 2025-11-07
 
 ### Added

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "uv_build"
 
 [project]
 name = "hassette"
-version = "0.15.4"
+version = "0.15.5"
 description = "Hassette is a simple, modern, async-first Python framework for building Home Assistant automations."
 readme = "README.md"
 authors = [{ name = "Jessica", email = "12jessicasmith34@gmail.com" }]

src/hassette/config/classes.py

@@ -31,7 +31,7 @@ def __init__(self, settings_cls: type[BaseSettings], toml_file: PathType | None
             super().__init__(settings_cls, self.toml_file_path)
             return
 
-        LOGGER.info("Merging 'hassette' section from TOML config into top level")
+        LOGGER.debug("Merging 'hassette' section from TOML config into top level")
         top_level_keys = set(self.toml_data.keys()) - {"hassette"}
         hassette_values = self.toml_data.pop("hassette")
         for key in top_level_keys.intersection(hassette_values.keys()):

src/hassette/config/core.py

@@ -109,7 +109,7 @@ def settings_customise_sources(
     """Access token for Home Assistant instance"""
 
     # has to be before apps to allow auto-detection
-    autodetect_apps: bool = Field(default=True)
+    autodetect_apps: bool = Field(default=True, validation_alias=AliasChoices("autodetect_apps", "auto_detect_apps"))
     """Whether to automatically detect apps in the app directory."""
 
     extend_autodetect_exclude_dirs: tuple[str, ...] = Field(default_factory=tuple)

src/hassette/config/helpers.py

@@ -10,6 +10,7 @@
 import platformdirs
 from packaging.version import Version
 
+from hassette import context
 from hassette.types.types import LOG_LEVELS
 
 LOG_LEVEL_VALUES = get_args(LOG_LEVELS)
@@ -37,20 +38,32 @@ def get_dev_mode() -> bool:
     Returns:
         True if developer mode is enabled, False otherwise.
     """
-    logger = logging.getLogger(__name__)
-    if "debugpy" in sys.modules:
-        logger.warning("Developer mode enabled via 'debugpy'")
-        return True
 
-    if sys.gettrace() is not None:
-        logger.warning("Developer mode enabled via 'sys.gettrace()'")
-        return True
+    curr_config = context.HASSETTE_CONFIG.get(None)
+    if curr_config:
+        # not sure if we can even change this during runtime, but for now we are not
+        # going to allow it
+        return curr_config.dev_mode
 
-    if sys.flags.dev_mode:
-        logger.warning("Developer mode enabled via 'python -X dev'")
-        return True
+    logger = logging.getLogger(__name__)
 
-    return False
+    enabled = False
+    reason = None
+
+    if "debugpy" in sys.modules:
+        enabled = True
+        reason = "debugpy"
+    elif sys.gettrace() is not None:
+        enabled = True
+        reason = "sys.gettrace()"
+    elif sys.flags.dev_mode:
+        enabled = True
+        reason = "python -X dev"
+
+    if enabled:
+        logger.info("Developer mode enabled (%s)", reason)
+
+    return enabled
 
 
 def default_config_dir() -> Path:

src/hassette/services/app_handler.py

@@ -363,7 +363,7 @@ async def refresh_config(self) -> tuple[dict[str, "AppManifest"], dict[str, "App
         # Reinitialize config to pick up changes.
         # https://docs.pydantic.dev/latest/concepts/pydantic_settings/#in-place-reloading
         try:
-            self.hassette.config.__init__()
+            self.hassette.config.reload()
         except Exception as e:
             self.logger.exception("Failed to reload configuration: %s", e)
 
@@ -383,7 +383,7 @@ async def handle_changes(self, changed_file_path: Path | None = None) -> None:
         orphans, new_apps, reimport_apps, reload_apps = self._calculate_app_changes(
             original_apps_config, curr_apps_config, changed_file_path
         )
-        self.logger.debug(
+        self.logger.info(
             "App changes detected - orphans: %s, new: %s, reimport: %s, reload: %s",
             orphans,
             new_apps,

tests/test_apps.py

@@ -54,6 +54,32 @@ def test_all_apps(self) -> None:
         assert "MyApp" in class_names, "MyApp should be in the list of running apps"
         assert "MyAppSync" in class_names, "MyAppSync should be in the list of running apps"
 
+    async def test_handle_changes_does_not_lose_apps(self) -> None:
+        """Verify that calling handle_changes() without config modifications preserves all running apps."""
+
+        orig_apps = set(self.app_handler.apps.keys())
+
+        event = asyncio.Event()
+
+        async def handler(*args, **kwargs):  # noqa
+            self.hassette.task_bucket.post_to_loop(event.set)
+
+        self.hassette._bus_service.add_listener(
+            Listener.create(
+                self.app_handler.task_bucket,
+                owner="test",
+                topic=HASSETTE_EVENT_APP_LOAD_COMPLETED,
+                handler=handler,
+                where=None,
+            )
+        )
+
+        await self.app_handler.handle_changes()
+        await asyncio.wait_for(event.wait(), timeout=1)
+
+        new_apps = set(self.app_handler.apps.keys())
+        assert orig_apps == new_apps, "No apps should be lost during handle_changes"
+
     async def test_handle_changes_disables_app(self) -> None:
         """Verify that editing hassette.toml to disable an app stops the running instance."""