tools (config): QoL improvements:

- correct the case of `dynamicSettingsRegister` and `dynamicSettings` which are `dict`, not
  classes.
- Use new `DynamicSettingsCollection` as base class for classes dynamically built during
  parsing, to avoid name conflict.
- Use `DynamicSettingsCollection` instead of `dict` in dynamic field (`plugin` and
  `component`). This correct inconsistency, and make linters happy.
- Catch `TOMLDecodeError` when parsing config, to show a more readable error message
  instead of full backtrace.

libervia/backend/tools/config.py

@@ -22,8 +22,15 @@
 from collections import defaultdict
 from pathlib import Path
 from socket import getfqdn
-from typing import Annotated, Any, Literal, Self, TypeVar, cast
+from tomllib import TOMLDecodeError
+from typing import Annotated, Literal, Self, TypeVar, cast
 
+from libervia.backend.core import exceptions
+from libervia.backend.core.constants import Const as C, xdg_data_home
+from libervia.backend.core.i18n import _
+from libervia.backend.core.log import getLogger
+from libervia.backend.models.types import JIDType
+from libervia.backend.tools.common.files_utils import get_downloads_dir
 from pydantic import (
     AfterValidator,
     BaseModel,
@@ -42,21 +49,14 @@ from pydantic_settings import (
     TomlConfigSettingsSource,
 )
 
-from libervia.backend.core import exceptions
-from libervia.backend.core.constants import Const as C, xdg_data_home
-from libervia.backend.core.i18n import _
-from libervia.backend.core.log import getLogger
-from libervia.backend.models.types import JIDType
-from libervia.backend.tools.common.files_utils import get_downloads_dir
-
 log = getLogger(__name__)
 
 expanduser_validator = AfterValidator(lambda p: p.expanduser().resolve())
 
 cached_config: "Settings|None" = None
-DynamicSettingsRegister = dict[str, "type[DynamicSettingsBase]"]
-DynamicSettings: dict[str, DynamicSettingsRegister | type["DynamicSettingsBase"]] = (
-    defaultdict(DynamicSettingsRegister)
+dynamicSettingsRegister = dict[str, "type[DynamicSettingsBase]"]
+dynamicSettings: dict[str, dynamicSettingsRegister | type["DynamicSettingsBase"]] = (
+    defaultdict(dynamicSettingsRegister)
 )
 
 
@@ -123,7 +123,7 @@ class DynamicSettingsBase(ConfigOptions):
             #   normalized on plugin import.
             sub_key = sub_key.replace("-", "_").lower()
             cls._sub_key = sub_key
-            register = DynamicSettings[key]
+            register = dynamicSettings[key]
             assert isinstance(register, dict)
             if sub_key in register:
                 raise exceptions.ConflictError(
@@ -133,7 +133,7 @@ class DynamicSettingsBase(ConfigOptions):
             cls._import_name = plugin_info.get(C.PI_IMPORT_NAME)
         else:
             cls._sub_key = None
-            DynamicSettings[key] = cls
+            dynamicSettings[key] = cls
 
 
 class PluginSettings(DynamicSettingsBase):
@@ -189,6 +189,10 @@ class FrontendSettings(DynamicSettingsBase):
         super()._init_subclass(key=key)
 
 
+class DynamicSettingsCollection(BaseModel):
+    """Base class for collection of DynamicSettings."""
+
+
 D = TypeVar("D", bound=DynamicSettingsBase)
 
 
@@ -414,9 +418,12 @@ class Settings(BaseSettings):
         default_factory=dict,
         description="Application specific settings, used by app manager.",
     )
-    plugin: dict = Field(default_factory=dict, description="Plugin specific settings.")
-    component: dict = Field(
-        default_factory=dict, description="Component specific settings."
+    plugin: DynamicSettingsCollection = Field(
+        default_factory=DynamicSettingsCollection, description="Plugin specific settings."
+    )
+    component: DynamicSettingsCollection = Field(
+        default_factory=DynamicSettingsCollection,
+        description="Component specific settings.",
     )
 
     @field_validator("bridges", mode="after")
@@ -519,10 +526,11 @@ def parse_main_conf(log_filenames: bool = False, ignore_cache=False) -> Settings
 
     if ignore_cache or cached_config is None:
         dynamic_settings_kw = {}
-        for key, settings in DynamicSettings.items():
+        for key, settings in dynamicSettings.items():
             if isinstance(settings, dict):
                 NewSettingsModel = create_model(
-                    f"{key.title()}Settings",
+                    f"{key.title()}SettingsCollection",
+                    __base__=DynamicSettingsCollection,
                     **cast(
                         dict,
                         {
@@ -549,10 +557,12 @@ def parse_main_conf(log_filenames: bool = False, ignore_cache=False) -> Settings
         try:
             cached_config = LiberviaSettings()
         except ValidationError as e:
-            log.error(f"Settings are invalid, please fix your configuration: {e}")
-            raise exceptions.ConfigError
-        except:
+            raise exceptions.ConfigError(e)
+        except TOMLDecodeError as e:
+            log.error(f"You configuration file is invalid: {e}")
+            raise exceptions.ConfigError from e
+        except Exception as e:
             log.exception("Can't parse settings.")
-            raise exceptions.InternalError
+            raise exceptions.InternalError from e
 
     return cached_config