Ensure invulnerables have associated validator keys before they are set (#812)

* Added check to ensure invulnerables have associated validator keys before they are set

* Added check to ensure invulnerables have associated validator keys before they are set

* Update pallets/collator-selection/src/lib.rs

Co-authored-by: Keith Yeung <kungfukeith11@gmail.com>

* Added test for associated validators when setting invulnerables

* FMT

Co-authored-by: Omadoye Abraham <abraham.o@turing.com>
Co-authored-by: Ricardo Rius <9488369+riusricardo@users.noreply.github.com>
Co-authored-by: Keith Yeung <kungfukeith11@gmail.com>
Co-authored-by: Bastian Köcher <info@kchr.de>

cumulus/pallets/collator-selection/src/lib.rs

@@ -296,6 +296,17 @@ pub mod pallet {
 					"invulnerables > T::MaxInvulnerables; you might need to run benchmarks again"
 				);
 			}
+
+			// check if the invulnerables have associated validator keys before they are set
+			for account_id in &new {
+				let validator_key = T::ValidatorIdOf::convert(account_id.clone())
+					.ok_or(Error::<T>::NoAssociatedValidatorId)?;
+				ensure!(
+					T::ValidatorRegistration::is_registered(&validator_key),
+					Error::<T>::ValidatorNotRegistered
+				);
+			}
+
 			<Invulnerables<T>>::put(&new);
 			Self::deposit_event(Event::NewInvulnerables(new));
 			Ok(().into())

cumulus/pallets/collator-selection/src/tests.rs

@@ -48,6 +48,16 @@ fn it_should_set_invulnerables() {
 			CollatorSelection::set_invulnerables(Origin::signed(1), new_set.clone()),
 			BadOrigin
 		);
+
+		// cannot set invulnerables without associated validator keys
+		let invulnerables = vec![7];
+		assert_noop!(
+			CollatorSelection::set_invulnerables(
+				Origin::signed(RootAccount::get()),
+				invulnerables.clone()
+			),
+			Error::<Test>::ValidatorNotRegistered
+		);
 	});
 }