Rb staking pallet validator commission change event (#10827)

* commission-changed-event-and-deposit

* deposit_event fix

* commission_changed_event_works

* fmt

* CommissionChanged -> ValidatorPrefsUpdated

* event ValidatorPrefs

* updated commet

* fmt

* Update frame/staking/src/pallet/mod.rs

Co-authored-by: joe petrowski <25483142+joepetrowski@users.noreply.github.com>

* Update frame/staking/src/pallet/mod.rs

Co-authored-by: joe petrowski <25483142+joepetrowski@users.noreply.github.com>

* Update frame/staking/src/tests.rs

Co-authored-by: joe petrowski <25483142+joepetrowski@users.noreply.github.com>

Co-authored-by: joe petrowski <25483142+joepetrowski@users.noreply.github.com>

substrate/frame/staking/src/pallet/mod.rs

@@ -628,6 +628,8 @@ pub mod pallet {
 		Chilled(T::AccountId),
 		/// The stakers' rewards are getting paid. \[era_index, validator_stash\]
 		PayoutStarted(EraIndex, T::AccountId),
+		/// A validator has set their preferences.
+		ValidatorPrefsSet(T::AccountId, ValidatorPrefs),
 	}
 
 	#[pallet::error]
@@ -1016,7 +1018,9 @@ pub mod pallet {
 			}
 
 			Self::do_remove_nominator(stash);
-			Self::do_add_validator(stash, prefs);
+			Self::do_add_validator(stash, prefs.clone());
+			Self::deposit_event(Event::<T>::ValidatorPrefsSet(ledger.stash, prefs));
+
 			Ok(())
 		}
 

substrate/frame/staking/src/tests.rs

@@ -4598,11 +4598,21 @@ fn capped_stakers_works() {
 #[test]
 fn min_commission_works() {
 	ExtBuilder::default().build_and_execute(|| {
+		// account 10 controls the stash from account 11
 		assert_ok!(Staking::validate(
 			Origin::signed(10),
 			ValidatorPrefs { commission: Perbill::from_percent(5), blocked: false }
 		));
 
+		// event emitted should be correct
+		assert_eq!(
+			*staking_events().last().unwrap(),
+			Event::ValidatorPrefsSet(
+				11,
+				ValidatorPrefs { commission: Perbill::from_percent(5), blocked: false }
+			)
+		);
+
 		assert_ok!(Staking::set_staking_configs(
 			Origin::root(),
 			ConfigOp::Remove,