diff --git a/frame/stake-tracker/src/mock.rs b/frame/stake-tracker/src/mock.rs
index d38364fb87137..9b007050e47ae 100644
--- a/frame/stake-tracker/src/mock.rs
+++ b/frame/stake-tracker/src/mock.rs
@@ -140,6 +140,9 @@ impl StakingInterface for StakingMock {
 	fn stake(
 		who: &Self::AccountId,
 	) -> Result<Stake<Self::AccountId, Self::Balance>, DispatchError> {
+		if *who >= 30 {
+			return Err(DispatchError::Other("not bonded"))
+		}
 		let stake = <Runtime as pallet_stake_tracker::Config>::Currency::total_balance(who);
 		Ok(Stake {
 			stash: *who,
diff --git a/frame/stake-tracker/src/tests.rs b/frame/stake-tracker/src/tests.rs
index 5affbaf818f0d..c522a1fb12e8a 100644
--- a/frame/stake-tracker/src/tests.rs
+++ b/frame/stake-tracker/src/tests.rs
@@ -22,6 +22,16 @@ mod on_stake_update {
 		});
 	}
 
+	#[test]
+	#[should_panic]
+	fn panics_when_not_bonded() {
+		ExtBuilder::default().build_and_execute(|| {
+			assert_eq!(VoterList::count(), 0);
+			// user without stake
+			assert_storage_noop!(StakeTracker::on_stake_update(&30, None));
+		});
+	}
+
 	#[test]
 	fn noop_when_not_validator_or_nominator() {
 		ExtBuilder::default().build_and_execute(|| {
@@ -50,3 +60,173 @@ mod on_stake_update {
 		});
 	}
 }
+
+mod on_nominator_update {
+	use super::*;
+	#[test]
+	fn noop_when_in_the_list() {
+		ExtBuilder::default().build_and_execute(|| {
+			assert_eq!(VoterList::count(), 0);
+
+			// usual user, validator, nominator
+			for (idx, id) in [1, 10, 20].iter().enumerate() {
+				let _ = VoterList::on_insert(*id, 1000);
+				assert_storage_noop!(StakeTracker::on_nominator_update(id, Vec::new()));
+			}
+		});
+	}
+
+	#[test]
+	#[should_panic]
+	fn panics_when_not_bonded() {
+		ExtBuilder::default().build_and_execute(|| {
+			assert_eq!(VoterList::count(), 0);
+			// user without stake
+			assert_storage_noop!(StakeTracker::on_nominator_update(&30, Vec::new()));
+		});
+	}
+
+	#[test]
+	// It is the caller's problem to make sure `on_nominator_update` is called in the right context.
+	fn works_for_everyone() {
+		ExtBuilder::default().build_and_execute(|| {
+			assert_eq!(VoterList::count(), 0);
+
+			// usual user, validator, nominator
+			for id in [1, 10, 20] {
+				StakeTracker::on_nominator_update(&id, Vec::new());
+				assert_eq!(
+					VoterList::get_score(&id).unwrap(),
+					Pallet::<Runtime>::to_vote(Staking::stake(&id).map(|s| s.active).unwrap())
+				);
+			}
+		});
+	}
+}
+
+mod on_validator_add {
+	use super::*;
+	#[test]
+	fn noop_when_in_the_list() {
+		ExtBuilder::default().build_and_execute(|| {
+			assert_eq!(VoterList::count(), 0);
+
+			// usual user, validator, nominator
+			for id in [1, 10, 20] {
+				let _ = VoterList::on_insert(id, 1000);
+				assert_storage_noop!(StakeTracker::on_validator_add(&id));
+			}
+		});
+	}
+
+	#[test]
+	#[should_panic]
+	fn panics_when_not_bonded() {
+		ExtBuilder::default().build_and_execute(|| {
+			assert_eq!(VoterList::count(), 0);
+			// user without stake
+			assert_storage_noop!(StakeTracker::on_validator_add(&30));
+		});
+	}
+
+	#[test]
+	// It is the caller's problem to make sure `on_validator_add` is called in the right context.
+	fn works_for_everyone() {
+		ExtBuilder::default().build_and_execute(|| {
+			assert_eq!(VoterList::count(), 0);
+
+			// usual user, validator, nominator
+			for id in [1, 10, 20] {
+				StakeTracker::on_validator_add(&id);
+				assert_eq!(
+					VoterList::get_score(&id).unwrap(),
+					Pallet::<Runtime>::to_vote(Staking::stake(&id).map(|s| s.active).unwrap())
+				);
+			}
+		});
+	}
+}
+
+mod on_validator_remove {
+	use super::*;
+	#[test]
+	fn noop_when_not_in_the_list() {
+		ExtBuilder::default().build_and_execute(|| {
+			assert_eq!(VoterList::count(), 0);
+
+			// usual user, validator, nominator, not bonded
+			for id in [1, 10, 20, 30] {
+				assert_storage_noop!(StakeTracker::on_validator_remove(&id));
+			}
+		});
+	}
+
+	#[test]
+	// It is the caller's problem to make sure `on_validator_remove` is called in the right context.
+	fn works_for_everyone_also_unbonded() {
+		ExtBuilder::default().build_and_execute(|| {
+			assert_eq!(VoterList::count(), 0);
+
+			// usual user, validator, nominator
+			for id in [1, 10, 20, 30] {
+				let _ = VoterList::on_insert(id, 100);
+				assert_eq!(VoterList::count(), 1);
+				StakeTracker::on_validator_remove(&id);
+				assert_eq!(VoterList::count(), 0);
+			}
+		});
+	}
+}
+
+mod on_nominator_remove {
+	use super::*;
+	#[test]
+	fn noop_when_not_in_the_list() {
+		ExtBuilder::default().build_and_execute(|| {
+			assert_eq!(VoterList::count(), 0);
+
+			// usual user, validator, nominator, not bonded
+			for id in [1, 10, 20, 30] {
+				assert_storage_noop!(StakeTracker::on_nominator_remove(&id, Vec::new()));
+			}
+		});
+	}
+
+	#[test]
+	// It is the caller's problem to make sure `on_nominator_remove` is called in the right context.
+	fn works_for_everyone_also_unbonded() {
+		ExtBuilder::default().build_and_execute(|| {
+			assert_eq!(VoterList::count(), 0);
+
+			// usual user, validator, nominator
+			for id in [1, 10, 20, 30] {
+				let _ = VoterList::on_insert(id, 100);
+				assert_eq!(VoterList::count(), 1);
+				StakeTracker::on_nominator_remove(&id, Vec::new());
+				assert_eq!(VoterList::count(), 0);
+			}
+		});
+	}
+}
+
+mod on_unstake {
+	use super::*;
+
+	#[test]
+	fn noop() {
+		ExtBuilder::default().build_and_execute(|| {
+			assert_eq!(VoterList::count(), 0);
+
+			// usual user, validator, nominator, not bonded
+			for id in [1, 10, 20, 30] {
+				assert_storage_noop!(StakeTracker::on_unstake(&id));
+			}
+
+			// usual user, validator, nominator, not bonded
+			for id in [1, 10, 20, 30] {
+				VoterList::on_insert(id, 100);
+				assert_storage_noop!(StakeTracker::on_unstake(&id));
+			}
+		});
+	}
+}