Ensure all choices are the same type as the parameter type

Fixes #7625

discord/app_commands/commands.py

@@ -223,9 +223,9 @@ def _populate_choices(params: Dict[str, CommandParameter], all_choices: Dict[str
         if param.type not in (AppCommandOptionType.string, AppCommandOptionType.number, AppCommandOptionType.integer):
             raise TypeError('choices are only supported for integer, string, or number option types')
 
-        # There's a type safety hole if someone does Choice[float] as an annotation
-        # but the values are actually Choice[int]. Since the input-output is the same this feels
-        # safe enough to ignore.
+        if not all(param.type == choice._option_type for choice in choices):
+            raise TypeError('choices must all have the same inner option type as the parameter choice type')
+
         param.choices = choices
 
     if all_choices:

discord/app_commands/models.py

@@ -188,6 +188,19 @@ class Choice(Generic[ChoiceT]):
     def __repr__(self) -> str:
         return f'{self.__class__.__name__}(name={self.name!r}, value={self.value!r})'
 
+    @property
+    def _option_type(self) -> AppCommandOptionType:
+        if isinstance(self.value, int):
+            return AppCommandOptionType.integer
+        elif isinstance(self.value, float):
+            return AppCommandOptionType.number
+        elif isinstance(self.value, str):
+            return AppCommandOptionType.string
+        else:
+            raise TypeError(
+                f'invalid Choice value type given, expected int, str, or float but received {self.value.__class__!r}'
+            )
+
     def to_dict(self) -> ApplicationCommandOptionChoice:
         return {
             'name': self.name,