Raise if custom_id is not a str

discord/ui/button.py

@@ -105,6 +105,9 @@ class Button(Item[V]):
         if url is None and custom_id is None:
             custom_id = os.urandom(16).hex()
 
+        if custom_id is not None and not isinstance(custom_id, str):
+            raise TypeError(f'expected custom_id to be str not {custom_id.__class__!r}')
+
         if url is not None:
             style = ButtonStyle.link
 

discord/ui/select.py

@@ -111,6 +111,9 @@ class Select(Item[V]):
         self._selected_values: List[str] = []
         self._provided_custom_id = custom_id is not MISSING
         custom_id = os.urandom(16).hex() if custom_id is MISSING else custom_id
+        if not isinstance(custom_id, str):
+            raise TypeError(f'expected custom_id to be str not {custom_id.__class__!r}')
+
         options = [] if options is MISSING else options
         self._underlying = SelectMenu._raw_construct(
             custom_id=custom_id,

discord/ui/text_input.py

@@ -104,6 +104,9 @@ class TextInput(Item[V]):
         self._value: Optional[str] = default
         self._provided_custom_id = custom_id is not MISSING
         custom_id = os.urandom(16).hex() if custom_id is MISSING else custom_id
+        if not isinstance(custom_id, str):
+            raise TypeError(f'expected custom_id to be str not {custom_id.__class__!r}')
+
         self._underlying = TextInputComponent._raw_construct(
             type=ComponentType.text_input,
             label=label,