Raise configuration errors for missing dict keys

royalnet/commands/__init__.py

@@ -8,6 +8,7 @@ from .event import Event
 from .errors import \
     CommandError, InvalidInputError, UnsupportedError, ConfigurationError, ExternalError, UserError, ProgramError
 from .keyboardkey import KeyboardKey
+from .configdict import ConfigDict
 
 __all__ = [
     "CommandInterface",
@@ -23,4 +24,5 @@ __all__ = [
     "ProgramError",
     "Event",
     "KeyboardKey",
+    "ConfigDict",
 ]

royalnet/commands/commandinterface.py

@@ -1,6 +1,7 @@
 from typing import *
 import asyncio as aio
 from .errors import UnsupportedError
+from .configdict import ConfigDict
 
 if TYPE_CHECKING:
     from .event import Event
@@ -36,7 +37,7 @@ class CommandInterface:
         A reference to a :class:`~royalnet.constellation.Constellation`."""
 
     def __init__(self, config: Dict[str, Any]):
-        self.config: Dict[str, Any] = config
+        self.config: ConfigDict[str, Any] = ConfigDict.convert(config)
         """The config section for the pack of the command."""
 
         # Will be bound after the command/event has been created

royalnet/commands/configdict.py

@@ -0,0 +1,20 @@
+from .errors import ConfigurationError
+
+
+class ConfigDict(dict):
+    def __missing__(self, key):
+        raise ConfigurationError(f"Missing config key '{key}'")
+
+    @classmethod
+    def convert(cls, item):
+        if isinstance(item, dict):
+            cd = ConfigDict()
+            for key in item:
+                cd[key] = cls.convert(item[key])
+            return cd
+        elif isinstance(item, list):
+            nl = []
+            for obj in item:
+                nl.append(cls.convert(obj))
+        else:
+            return item