git.delta.rocks / unique-network / refs/commits / d41364fb01e4

--- a/pallets/collator-selection/src/benchmarking.rs
+++ b/pallets/collator-selection/src/benchmarking.rs
@@ -130,7 +130,7 @@
 	where_clause { where T: pallet_authorship::Config + session::Config }
 
 	set_invulnerables {
-		let b in 1 .. T::MaxInvulnerables::get();
+		let b in 1 .. T::MaxCollators::get();
 		let new_invulnerables = register_validators::<T>(b);
 		let origin = T::UpdateOrigin::successful_origin();
 	}: {
@@ -142,16 +142,16 @@
 		assert_last_event::<T>(Event::NewInvulnerables{invulnerables: new_invulnerables}.into());
 	}
 
-	set_desired_candidates {
+	set_desired_collators {
 		let max: u32 = 999;
 		let origin = T::UpdateOrigin::successful_origin();
 	}: {
 		assert_ok!(
-			<CollatorSelection<T>>::set_desired_candidates(origin, max.clone())
+			<CollatorSelection<T>>::set_desired_collators(origin, max.clone())
 		);
 	}
 	verify {
-		assert_last_event::<T>(Event::NewDesiredCandidates{desired_candidates: max}.into());
+		assert_last_event::<T>(Event::NewDesiredCollators{desired_collators: max}.into());
 	}
 
 	set_license_bond {
@@ -169,10 +169,10 @@
 	// worse case is when we have all the max-candidate slots filled except one, and we fill that
 	// one.
 	register_as_candidate {
-		let c in 1 .. T::MaxCandidates::get();
+		let c in 1 .. T::MaxCollators::get();
 
 		<LicenseBond<T>>::put(T::Currency::minimum_balance());
-		<DesiredCandidates<T>>::put(c + 1);
+		<DesiredCollators<T>>::put(c + 1);
 
 		register_validators::<T>(c);
 		register_candidates::<T>(c);
@@ -194,9 +194,9 @@
 
 	// worse case is the last candidate leaving.
 	leave_intent {
-		let c in (T::MinCandidates::get() + 1) .. T::MaxCandidates::get();
+		let c in (T::MinCandidates::get() + 1) .. T::MaxCollators::get();
 		<LicenseBond<T>>::put(T::Currency::minimum_balance());
-		<DesiredCandidates<T>>::put(c);
+		<DesiredCollators<T>>::put(c);
 
 		register_validators::<T>(c);
 		register_candidates::<T>(c);
@@ -230,11 +230,11 @@
 
 	// worst case for new session.
 	new_session {
-		let r in 1 .. T::MaxCandidates::get();
-		let c in 1 .. T::MaxCandidates::get();
+		let r in 1 .. T::MaxCollators::get();
+		let c in 1 .. T::MaxCollators::get();
 
 		<LicenseBond<T>>::put(T::Currency::minimum_balance());
-		<DesiredCandidates<T>>::put(c);
+		<DesiredCollators<T>>::put(c);
 		frame_system::Pallet::<T>::set_block_number(0u32.into());
 
 		register_validators::<T>(c);

--- a/pallets/collator-selection/src/lib.rs
+++ b/pallets/collator-selection/src/lib.rs
@@ -98,10 +98,7 @@
 		dispatch::{DispatchClass, DispatchResultWithPostInfo},
 		inherent::Vec,
 		pallet_prelude::*,
-		sp_runtime::{
-			traits::{AccountIdConversion, CheckedSub, Saturating, Zero},
-			RuntimeDebug,
-		},
+		sp_runtime::traits::{AccountIdConversion, CheckedSub, Saturating, Zero},
 		traits::{
 			Currency, EnsureOrigin, ExistenceRequirement::KeepAlive, ReservableCurrency,
 			ValidatorRegistration,
@@ -145,19 +142,9 @@
 
 		/// Account Identifier from which the internal Pot is generated.
 		type PotId: Get<PalletId>;
-
-		/// Maximum number of candidates that we should have. This is enforced in code.
-		///
-		/// This does not take into account the invulnerables.
-		type MaxCandidates: Get<u32>;
 
-		/// Minimum number of candidates that we should have. This is used for disaster recovery.
-		///
-		/// This does not take into account the invulnerables.
-		type MinCandidates: Get<u32>;
-
-		/// Maximum number of invulnerables. This is enforced in code.
-		type MaxInvulnerables: Get<u32>;
+		/// Maximum number of candidates and invulnerables that we should have. This is enforced in code.
+		type MaxCollators: Get<u32>;
 
 		/// If kicked, how much of the collator's deposit will be slashed and sent to the slash destination.
 		type SlashRatio: Get<Perbill>;
@@ -175,17 +162,6 @@
 
 		/// The weight information of this pallet.
 		type WeightInfo: WeightInfo;
-	}
-
-	/// Basic information about a collation candidate.
-	#[derive(
-		PartialEq, Eq, Clone, Encode, Decode, RuntimeDebug, scale_info::TypeInfo, MaxEncodedLen,
-	)]
-	pub struct LicenseInfo<AccountId, Balance> {
-		/// Account identifier.
-		pub who: AccountId,
-		/// Reserved deposit.
-		pub deposit: Balance,
 	}
 
 	#[pallet::pallet]
@@ -196,7 +172,7 @@
 	#[pallet::storage]
 	#[pallet::getter(fn invulnerables)]
 	pub type Invulnerables<T: Config> =
-		StorageValue<_, BoundedVec<T::AccountId, T::MaxInvulnerables>, ValueQuery>;
+		StorageValue<_, BoundedVec<T::AccountId, T::MaxCollators>, ValueQuery>;
 
 	/// The (community) collation license holders.
 	#[pallet::storage]
@@ -209,7 +185,7 @@
 	#[pallet::getter(fn candidates)]
 	pub type Candidates<T: Config> = StorageValue<
 		_,
-		BoundedVec<T::AccountId, T::MaxCandidates>, //LicenseInfo<T::AccountId, BalanceOf<T>>, T::MaxCandidates>, // license ID?
+		BoundedVec<T::AccountId, T::MaxCollators>, //LicenseInfo<T::AccountId, BalanceOf<T>>, T::MaxCollators>, // license ID?
 		ValueQuery,
 	>;
 
@@ -228,10 +204,10 @@
 
 	/// Desired number of candidates.
 	///
-	/// This should ideally always be less than [`Config::MaxCandidates`] for weights to be correct.
+	/// This should ideally always be less than [`Config::MaxCollators`] for weights to be correct.
 	#[pallet::storage]
-	#[pallet::getter(fn desired_candidates)]
-	pub type DesiredCandidates<T> = StorageValue<_, u32, ValueQuery>;
+	#[pallet::getter(fn desired_collators)]
+	pub type DesiredCollators<T> = StorageValue<_, u32, ValueQuery>;
 
 	/// Fixed amount to deposit to become a collator.
 	///
@@ -245,7 +221,7 @@
 		pub invulnerables: Vec<T::AccountId>,
 		pub license_bond: BalanceOf<T>,
 		pub kick_threshold: T::BlockNumber,
-		pub desired_candidates: u32,
+		pub desired_collators: u32,
 	}
 
 	#[cfg(feature = "std")]
@@ -255,7 +231,7 @@
 				invulnerables: Default::default(),
 				license_bond: Default::default(),
 				kick_threshold: T::BlockNumber::one(),
-				desired_candidates: Default::default(),
+				desired_collators: Default::default(),
 			}
 		}
 	}
@@ -273,16 +249,16 @@
 			);
 
 			let bounded_invulnerables =
-				BoundedVec::<_, T::MaxInvulnerables>::try_from(self.invulnerables.clone())
-					.expect("genesis invulnerables are more than T::MaxInvulnerables");
+				BoundedVec::<_, T::MaxCollators>::try_from(self.invulnerables.clone())
+					.expect("genesis invulnerables are more than T::MaxCollators");
 			assert!(
-				T::MaxCandidates::get() >= self.desired_candidates,
-				"genesis desired_candidates are more than T::MaxCandidates",
+				T::MaxCollators::get() >= self.desired_collators,
+				"genesis desired_collators are more than T::MaxCollators",
 			);
 
-			<DesiredCandidates<T>>::put(&self.desired_candidates);
-			<LicenseBond<T>>::put(&self.license_bond);
-			<KickThreshold<T>>::put(&self.kick_threshold);
+			<DesiredCollators<T>>::put(self.desired_collators);
+			<LicenseBond<T>>::put(self.license_bond);
+			<KickThreshold<T>>::put(self.kick_threshold);
 			<Invulnerables<T>>::put(bounded_invulnerables);
 		}
 	}
@@ -290,8 +266,8 @@
 	#[pallet::event]
 	#[pallet::generate_deposit(pub(super) fn deposit_event)]
 	pub enum Event<T: Config> {
-		NewDesiredCandidates {
-			desired_candidates: u32,
+		NewDesiredCollators {
+			desired_collators: u32,
 		},
 		NewLicenseBond {
 			bond_amount: BalanceOf<T>,
@@ -326,14 +302,12 @@
 	pub enum Error<T> {
 		/// Too many candidates
 		TooManyCandidates,
-		/// Too few candidates
-		TooFewCandidates,
 		/// Unknown error
 		Unknown,
 		/// Permission issue
 		Permission,
 		/// User already holds license to collate
-		AlreadyLicenseHolder,
+		AlreadyHoldingLicense,
 		/// User does not hold a license to collate
 		NoLicense,
 		/// User is already a candidate
@@ -360,7 +334,7 @@
 	#[pallet::call]
 	impl<T: Config> Pallet<T> {
 		/// Add a collator to the list of invulnerable (fixed) collators.
-		#[pallet::weight(T::WeightInfo::set_invulnerables(1 as u32))] // todo:collator weight
+		#[pallet::weight(T::WeightInfo::set_invulnerables(1u32))] // todo:collator weight
 		pub fn add_invulnerable(
 			origin: OriginFor<T>,
 			new: T::AccountId,
@@ -378,12 +352,13 @@
 			if Self::invulnerables().contains(&new) {
 				return Ok(().into());
 			}
-
-			// todo:collator check license holders, release moneys, promotion!
-			// force_release_license? Error::<T>::lreadyLicenseHolder?
 
 			<Invulnerables<T>>::try_append(new.clone())
 				.map_err(|_| Error::<T>::TooManyInvulnerables)?;
+
+			// try to offboard the new invulnerable if it was a collator candidate before
+			let _ = Self::try_remove_candidate(&new);
+
 			Self::deposit_event(Event::InvulnerableAdded { invulnerable: new });
 			Ok(().into())
 		}
@@ -417,22 +392,19 @@
 			Ok(().into())
 		}
 
-		/// Set the ideal number of collators (not including the invulnerables).
-		/// If lowering this number, then the number of running collators could be higher than this figure.
+		/// Set the ideal number of collators. If lowering this number,
+		/// then the number of running collators could be higher than this figure.
 		/// Aside from that edge case, there should be no other way to have more collators than the desired number.
-		#[pallet::weight(T::WeightInfo::set_desired_candidates())]
-		pub fn set_desired_candidates(
-			origin: OriginFor<T>,
-			max: u32,
-		) -> DispatchResultWithPostInfo {
+		#[pallet::weight(T::WeightInfo::set_desired_collators())]
+		pub fn set_desired_collators(origin: OriginFor<T>, max: u32) -> DispatchResultWithPostInfo {
 			T::UpdateOrigin::ensure_origin(origin)?;
 			// we trust origin calls, this is just a for more accurate benchmarking
-			if max > T::MaxCandidates::get() {
-				log::warn!("max > T::MaxCandidates; you might need to run benchmarks again");
+			if max > T::MaxCollators::get() {
+				log::warn!("max > T::MaxCollators; you might need to run benchmarks again");
 			}
-			<DesiredCandidates<T>>::put(&max);
-			Self::deposit_event(Event::NewDesiredCandidates {
-				desired_candidates: max,
+			<DesiredCollators<T>>::put(max);
+			Self::deposit_event(Event::NewDesiredCollators {
+				desired_collators: max,
 			});
 			Ok(().into())
 		}
@@ -444,7 +416,7 @@
 			bond: BalanceOf<T>,
 		) -> DispatchResultWithPostInfo {
 			T::UpdateOrigin::ensure_origin(origin)?;
-			<LicenseBond<T>>::put(&bond);
+			<LicenseBond<T>>::put(bond);
 			Self::deposit_event(Event::NewLicenseBond { bond_amount: bond });
 			Ok(().into())
 		}
@@ -470,19 +442,19 @@
 		/// (a) already have registered session keys and (b) be able to reserve the `LicenseBond`.
 		///
 		/// This call is not available to `Invulnerable` collators.
-		#[pallet::weight(T::WeightInfo::register_as_candidate(T::MaxCandidates::get()))] // todo:collator weight
+		#[pallet::weight(T::WeightInfo::register_as_candidate(T::MaxCollators::get()))] // todo:collator weight
 		pub fn get_license(origin: OriginFor<T>) -> DispatchResultWithPostInfo {
 			// register_as_candidate
 			let who = ensure_signed(origin)?;
 
 			if Licenses::<T>::contains_key(&who) {
-				return Ok(().into());
+				return Err(Error::<T>::AlreadyHoldingLicense.into());
 			}
 
-			ensure!(
+			/*ensure!(
 				!Self::invulnerables().contains(&who),
 				Error::<T>::AlreadyInvulnerable
-			);
+			);*/
 
 			let validator_key = T::ValidatorIdOf::convert(who.clone())
 				.ok_or(Error::<T>::NoAssociatedValidatorId)?;
@@ -507,7 +479,7 @@
 					return Err(BadOrigin.into());
 				}
 				if candidates.iter().any(|candidate| *candidate == who) {
-					Err(Error::<T>::AlreadyLicenseHolder)?
+					Err(Error::<T>::AlreadyHoldingLicense)?
 				} else {
 					T::Currency::reserve(&who, deposit)?;
 					candidates
@@ -532,7 +504,7 @@
 		/// The account must already hold a license, and cannot offboard immediately during a session.
 		///
 		/// This call is not available to `Invulnerable` collators.
-		#[pallet::weight(T::WeightInfo::register_as_candidate(T::MaxCandidates::get()))] // todo:collator weight
+		#[pallet::weight(T::WeightInfo::register_as_candidate(T::MaxCollators::get()))] // todo:collator weight
 		pub fn onboard(origin: OriginFor<T>) -> DispatchResultWithPostInfo {
 			// register_as_candidate
 			let who = ensure_signed(origin)?;
@@ -540,9 +512,10 @@
 			// ensure the user obtained the license.
 			ensure!(Licenses::<T>::contains_key(&who), Error::<T>::NoLicense);
 			// ensure we are below limit.
-			let length = <Candidates<T>>::decode_len().unwrap_or_default();
+			let length = <Candidates<T>>::decode_len().unwrap_or_default()
+				+ <Invulnerables<T>>::decode_len().unwrap_or_default();
 			ensure!(
-				(length as u32) < Self::desired_candidates(),
+				(length as u32) < Self::desired_collators(),
 				Error::<T>::TooManyCandidates
 			);
 			// todo:collator really need it?
@@ -551,8 +524,6 @@
 				Error::<T>::AlreadyInvulnerable
 			);
 
-			let deposit = Self::license_bond();
-			// First authored block is current block plus kick threshold to handle session delay
 			/*let incoming = LicenseInfo {
 				who: who.clone(),
 				deposit,
@@ -563,10 +534,10 @@
 					if candidates.iter().any(|candidate| *candidate == who) {
 						Err(Error::<T>::AlreadyCandidate)?
 					} else {
-						T::Currency::reserve(&who, deposit)?;
 						candidates
 							.try_push(who.clone())
 							.map_err(|_| Error::<T>::TooManyCandidates)?;
+						// First authored block is current block plus kick threshold to handle session delay
 						<LastAuthoredBlock<T>>::insert(
 							who.clone(),
 							frame_system::Pallet::<T>::block_number() + Self::kick_threshold(),
@@ -583,31 +554,31 @@
 		/// session change. The license to `onboard` later at any other time will remain.
 		///
 		/// This call will fail if the total number of candidates would drop below `MinCandidates`. todo:collator maybe not
-		#[pallet::weight(T::WeightInfo::leave_intent(T::MaxCandidates::get()))] // todo:collator weight
+		#[pallet::weight(T::WeightInfo::leave_intent(T::MaxCollators::get()))] // todo:collator weight
 		pub fn offboard(origin: OriginFor<T>) -> DispatchResultWithPostInfo {
 			// leave_intent
 			let who = ensure_signed(origin)?;
-			// todo:collator invulnerables and candidates should count against min candidates together
+			/* todo:collator invulnerables and candidates should count against min candidates together
 			ensure!(
 				Self::candidates().len() as u32 > T::MinCandidates::get(),
 				Error::<T>::TooFewCandidates
-			);
+			);*/
 			let current_count = Self::try_remove_candidate(&who)?;
 
-			Ok(Some(T::WeightInfo::leave_intent(current_count as u32)).into())
+			Ok(Some(T::WeightInfo::leave_intent(current_count as u32)).into()) // todo:collator weight
 		}
 
 		/// Forfeit `origin`'s own license. The `LicenseBond` will be unreserved immediately.
 		///
 		/// This call is not available to `Invulnerable` collators.
-		#[pallet::weight(T::WeightInfo::leave_intent(T::MaxCandidates::get()))] // todo:collator weight
+		#[pallet::weight(T::WeightInfo::leave_intent(T::MaxCollators::get()))] // todo:collator weight
 		pub fn release_license(origin: OriginFor<T>) -> DispatchResultWithPostInfo {
 			// leave_intent
 			let who = ensure_signed(origin)?;
-			// let current_count = Self::try_remove_candidate(&who, false)?;
-			Self::try_release_license(&who, false)?;
 
-			Ok(().into())
+			let current_count = Self::try_remove_candidate_and_release_license(&who, false, true)?;
+
+			Ok(Some(T::WeightInfo::leave_intent(current_count as u32)).into()) // todo:collator weight
 		}
 
 		/// Force deregister `origin` as a collator candidate as a governing authority, and revoke its license.
@@ -615,16 +586,15 @@
 		/// The `LicenseBond` will be unreserved and returned immediately.
 		///
 		/// This call is not available to `Invulnerable` collators.
-		#[pallet::weight(T::WeightInfo::leave_intent(T::MaxCandidates::get()))] // todo:collator weight
-		pub fn force_release_license(
+		#[pallet::weight(T::WeightInfo::leave_intent(T::MaxCollators::get()))] // todo:collator weight
+		pub fn force_revoke_license(
 			origin: OriginFor<T>,
 			who: T::AccountId,
 		) -> DispatchResultWithPostInfo {
 			// leave_intent
 			T::UpdateOrigin::ensure_origin(origin)?;
 
-			let current_count = Self::try_remove_candidate(&who)?;
-			Self::try_release_license(&who, false)?;
+			let current_count = Self::try_remove_candidate_and_release_license(&who, false, true)?;
 
 			Ok(Some(T::WeightInfo::leave_intent(current_count as u32)).into()) // todo:collator weight
 		}
@@ -636,6 +606,23 @@
 			T::PotId::get().into_account_truncating()
 		}
 
+		fn try_remove_candidate_and_release_license(
+			who: &T::AccountId,
+			should_slash: bool,
+			ignore_if_not_candidate: bool,
+		) -> Result<usize, DispatchError> {
+			let current_count = Self::try_remove_candidate(who);
+			let current_count = if ignore_if_not_candidate
+				&& current_count == Err(Error::<T>::NotCandidate.into())
+			{
+				<Candidates<T>>::decode_len().unwrap_or_default()
+			} else {
+				current_count?
+			};
+			Self::try_release_license(who, should_slash)?;
+			Ok(current_count)
+		}
+
 		/// Removes a candidate from the collator pool for the next session if they exist.
 		fn try_remove_candidate(who: &T::AccountId) -> Result<usize, DispatchError> {
 			let current_count =
@@ -657,7 +644,7 @@
 		/// Removes a candidate if they exist and sends them back their deposit, optionally slashed.
 		fn try_release_license(who: &T::AccountId, should_slash: bool) -> DispatchResult {
 			let mut deposit_returned = BalanceOf::<T>::default();
-			Licenses::<T>::try_mutate_exists(&who, |deposit| -> DispatchResult {
+			Licenses::<T>::try_mutate_exists(who, |deposit| -> DispatchResult {
 				if let Some(deposit) = deposit.take() {
 					if should_slash {
 						let slashed = T::SlashRatio::get() * deposit;
@@ -690,7 +677,7 @@
 		///
 		/// This is done on the fly, as frequent as we are told to do so, as the session manager.
 		pub fn assemble_collators(
-			candidates: BoundedVec<T::AccountId, T::MaxCandidates>,
+			candidates: BoundedVec<T::AccountId, T::MaxCollators>,
 		) -> Vec<T::AccountId> {
 			let mut collators = Self::invulnerables().to_vec();
 			collators.extend(candidates);
@@ -700,8 +687,8 @@
 		/// Kicks out candidates that did not produce a block in the kick threshold
 		/// and **confiscates** their deposits to the treasury.
 		pub fn kick_stale_candidates(
-			candidates: BoundedVec<T::AccountId, T::MaxCandidates>, //LicenseInfo<T::AccountId, BalanceOf<T>>
-		) -> BoundedVec<T::AccountId, T::MaxCandidates> {
+			candidates: BoundedVec<T::AccountId, T::MaxCollators>, //LicenseInfo<T::AccountId, BalanceOf<T>>
+		) -> BoundedVec<T::AccountId, T::MaxCollators> {
 			let now = frame_system::Pallet::<T>::block_number();
 			let kick_threshold = Self::kick_threshold();
 			candidates
@@ -709,21 +696,13 @@
 				.filter_map(|c| {
 					let last_block = <LastAuthoredBlock<T>>::get(c.clone());
 					let since_last = now.saturating_sub(last_block);
-					if since_last < kick_threshold ||
-						Self::candidates().len() as u32 <= T::MinCandidates::get()
-					{
+					if since_last < kick_threshold {
 						Some(c)
 					} else {
-						let outcome = Self::try_remove_candidate(&c);
+						let outcome = Self::try_remove_candidate_and_release_license(&c, true, false);
 						if let Err(why) = outcome {
-							log::warn!("Failed to remove candidate {:?}", why);
-							debug_assert!(false, "failed to remove candidate {:?}", why);
-							return None;
-						}
-						let outcome = Self::try_release_license(&c, true);
-						if let Err(why) = outcome {
-							log::warn!("Failed to release license {:?}", why);
-							debug_assert!(false, "failed to release license {:?}", why);
+							log::warn!("Failed to kick collator and release license {:?}", why);
+							debug_assert!(false, "failed to kick collator and release license {why:?}");
 						}
 						None
 					}

--- a/pallets/collator-selection/src/mock.rs
+++ b/pallets/collator-selection/src/mock.rs
@@ -206,9 +206,7 @@
 
 parameter_types! {
 	pub const PotId: PalletId = PalletId(*b"PotStake");
-	pub const MaxCandidates: u32 = 20;
-	pub const MaxInvulnerables: u32 = 20;
-	pub const MinCandidates: u32 = 1;
+	pub const MaxCollators: u32 = 20;
 	pub const MaxAuthorities: u32 = 100_000;
 	pub const SlashRatio: Perbill = Perbill::one();
 }
@@ -230,9 +228,7 @@
 	type Currency = Balances;
 	type UpdateOrigin = EnsureSignedBy<RootAccount, u64>;
 	type PotId = PotId;
-	type MaxCandidates = MaxCandidates;
-	type MinCandidates = MinCandidates;
-	type MaxInvulnerables = MaxInvulnerables;
+	type MaxCollators = MaxCollators;
 	// type KickThreshold = Period;
 	type SlashRatio = SlashRatio;
 	type TreasuryAccountId = ();
@@ -263,9 +259,9 @@
 		})
 		.collect::<Vec<_>>();
 	let collator_selection = collator_selection::GenesisConfig::<Test> {
-		desired_candidates: 2,
+		desired_collators: 5,
 		license_bond: 10,
-		kick_threshold: 1,
+		kick_threshold: 10,
 		invulnerables,
 	};
 	let session = pallet_session::GenesisConfig::<Test> { keys };

--- a/pallets/collator-selection/src/tests.rs
+++ b/pallets/collator-selection/src/tests.rs
@@ -31,7 +31,7 @@
 // limitations under the License.
 
 use crate as collator_selection;
-use crate::{mock::*, LicenseInfo, Error};
+use crate::{mock::*, Error};
 use frame_support::{
 	assert_noop, assert_ok,
 	traits::{Currency, GenesisBuild, OnInitialize},
@@ -39,10 +39,19 @@
 use pallet_balances::Error as BalancesError;
 use sp_runtime::traits::BadOrigin;
 
+fn get_license_and_onboard(account_id: <Test as frame_system::Config>::AccountId) {
+	assert_ok!(CollatorSelection::get_license(RuntimeOrigin::signed(
+		account_id
+	)));
+	assert_ok!(CollatorSelection::onboard(RuntimeOrigin::signed(
+		account_id
+	)));
+}
+
 #[test]
 fn basic_setup_works() {
 	new_test_ext().execute_with(|| {
-		assert_eq!(CollatorSelection::desired_candidates(), 2);
+		assert_eq!(CollatorSelection::desired_collators(), 5);
 		assert_eq!(CollatorSelection::license_bond(), 10);
 
 		assert!(CollatorSelection::candidates().is_empty());
@@ -51,6 +60,7 @@
 }
 
 // todo:collator add more tests later
+// invulnerable after onboard + invulnerables can bypass desired_candidates
 
 #[test]
 fn it_should_add_invulnerables() {
@@ -112,21 +122,21 @@
 }
 
 #[test]
-fn set_desired_candidates_works() {
+fn set_desired_collators_works() {
 	new_test_ext().execute_with(|| {
 		// given
-		assert_eq!(CollatorSelection::desired_candidates(), 2);
+		assert_eq!(CollatorSelection::desired_collators(), 5);
 
 		// can set
-		assert_ok!(CollatorSelection::set_desired_candidates(
+		assert_ok!(CollatorSelection::set_desired_collators(
 			RuntimeOrigin::signed(RootAccount::get()),
 			7
 		));
-		assert_eq!(CollatorSelection::desired_candidates(), 7);
+		assert_eq!(CollatorSelection::desired_collators(), 7);
 
 		// rejects bad origin
 		assert_noop!(
-			CollatorSelection::set_desired_candidates(RuntimeOrigin::signed(1), 8),
+			CollatorSelection::set_desired_collators(RuntimeOrigin::signed(1), 8),
 			BadOrigin
 		);
 	});
@@ -154,166 +164,246 @@
 }
 
 #[test]
-fn cannot_register_candidate_if_too_many() {
+fn cannot_onboard_candidate_with_no_license() {
 	new_test_ext().execute_with(|| {
-		// reset desired candidates:
-		<crate::DesiredCandidates<Test>>::put(0);
+		// can't onboard a candidate who did not get a license.
+		assert_noop!(
+			CollatorSelection::onboard(RuntimeOrigin::signed(3)),
+			Error::<Test>::NoLicense,
+		);
+
+		// but give it a license and welcome aboard.
+		assert_ok!(CollatorSelection::get_license(RuntimeOrigin::signed(3)));
+		assert_ok!(CollatorSelection::onboard(RuntimeOrigin::signed(3)));
+	})
+}
+
+#[test]
+fn cannot_onboard_candidate_if_too_many() {
+	new_test_ext().execute_with(|| {
+		// reset desired candidates
+		<crate::DesiredCollators<Test>>::put(0);
+
+		// can still get a license.
+		assert_ok!(CollatorSelection::get_license(RuntimeOrigin::signed(4)));
 
 		// can't accept anyone anymore.
 		assert_noop!(
-			CollatorSelection::register_as_candidate(RuntimeOrigin::signed(3)),
+			CollatorSelection::onboard(RuntimeOrigin::signed(4)),
 			Error::<Test>::TooManyCandidates,
 		);
 
-		// reset desired candidates:
-		<crate::DesiredCandidates<Test>>::put(1);
-		assert_ok!(CollatorSelection::register_as_candidate(
-			RuntimeOrigin::signed(4)
-		));
+		// reset desired candidates to invulnerables + 1
+		<crate::DesiredCollators<Test>>::put(3);
+		assert_ok!(CollatorSelection::onboard(RuntimeOrigin::signed(4)));
 
-		// but no more
+		// but no more.
+		assert_ok!(CollatorSelection::get_license(RuntimeOrigin::signed(5)));
 		assert_noop!(
-			CollatorSelection::register_as_candidate(RuntimeOrigin::signed(5)),
+			CollatorSelection::onboard(RuntimeOrigin::signed(5)),
 			Error::<Test>::TooManyCandidates,
 		);
 	})
 }
 
 #[test]
-fn cannot_unregister_candidate_if_too_few() {
+fn cannot_obtain_license_if_keys_not_registered() {
 	new_test_ext().execute_with(|| {
-		// reset desired candidates:
-		<crate::DesiredCandidates<Test>>::put(1);
-		assert_ok!(CollatorSelection::register_as_candidate(
-			RuntimeOrigin::signed(4)
-		));
-
-		// can not remove too few
+		// can't 7 because keys not registered.
 		assert_noop!(
-			CollatorSelection::leave_intent(RuntimeOrigin::signed(4)),
-			Error::<Test>::TooFewCandidates,
+			CollatorSelection::get_license(RuntimeOrigin::signed(7)),
+			Error::<Test>::ValidatorNotRegistered
 		);
 	})
 }
 
 #[test]
-fn cannot_register_as_candidate_if_invulnerable() {
+fn cannot_obtain_license_if_poor() {
 	new_test_ext().execute_with(|| {
-		assert_eq!(CollatorSelection::invulnerables(), vec![1, 2]);
+		assert_eq!(Balances::free_balance(&3), 100);
+		assert_eq!(Balances::free_balance(&33), 0);
 
-		// can't 1 because it is invulnerable.
-		assert_noop!(
-			CollatorSelection::register_as_candidate(RuntimeOrigin::signed(1)),
-			Error::<Test>::AlreadyInvulnerable,
-		);
-	})
-}
+		// works
+		assert_ok!(CollatorSelection::get_license(RuntimeOrigin::signed(3)));
 
-#[test]
-fn cannot_register_as_candidate_if_keys_not_registered() {
-	new_test_ext().execute_with(|| {
-		// can't 7 because keys not registered.
+		// poor
 		assert_noop!(
-			CollatorSelection::register_as_candidate(RuntimeOrigin::signed(7)),
-			Error::<Test>::ValidatorNotRegistered
+			CollatorSelection::get_license(RuntimeOrigin::signed(33)),
+			BalancesError::<Test>::InsufficientBalance,
 		);
-	})
+	});
 }
 
 #[test]
-fn cannot_register_dupe_candidate() {
+fn cannot_onboard_dupe_candidate() {
 	new_test_ext().execute_with(|| {
 		// can add 3 as candidate
-		assert_ok!(CollatorSelection::register_as_candidate(
-			RuntimeOrigin::signed(3)
-		));
-		let addition = LicenseInfo {
-			who: 3,
-			deposit: 10,
-		};
-		assert_eq!(CollatorSelection::candidates(), vec![addition]);
+		get_license_and_onboard(3);
+		assert_eq!(CollatorSelection::licenses(3), 10);
+		assert_eq!(CollatorSelection::candidates(), vec![3]);
 		assert_eq!(CollatorSelection::last_authored_block(3), 10);
 		assert_eq!(Balances::free_balance(3), 90);
 
 		// but no more
 		assert_noop!(
-			CollatorSelection::register_as_candidate(RuntimeOrigin::signed(3)),
+			CollatorSelection::get_license(RuntimeOrigin::signed(3)),
+			Error::<Test>::AlreadyHoldingLicense,
+		);
+		assert_noop!(
+			CollatorSelection::onboard(RuntimeOrigin::signed(3)),
 			Error::<Test>::AlreadyCandidate,
 		);
 	})
 }
 
 #[test]
-fn cannot_register_as_candidate_if_poor() {
+fn becoming_candidate_works() {
 	new_test_ext().execute_with(|| {
+		// given
+		assert_eq!(CollatorSelection::desired_collators(), 5);
+		assert_eq!(CollatorSelection::license_bond(), 10);
+		assert_eq!(CollatorSelection::candidates(), Vec::new());
+		assert_eq!(CollatorSelection::invulnerables(), vec![1, 2]);
+
+		// take two endowed, non-invulnerables accounts.
 		assert_eq!(Balances::free_balance(&3), 100);
-		assert_eq!(Balances::free_balance(&33), 0);
+		assert_eq!(Balances::free_balance(&4), 100);
 
-		// works
-		assert_ok!(CollatorSelection::register_as_candidate(
-			RuntimeOrigin::signed(3)
-		));
+		get_license_and_onboard(3);
+		get_license_and_onboard(4);
+
+		assert_eq!(Balances::free_balance(&3), 90);
+		assert_eq!(Balances::free_balance(&4), 90);
 
-		// poor
-		assert_noop!(
-			CollatorSelection::register_as_candidate(RuntimeOrigin::signed(33)),
-			BalancesError::<Test>::InsufficientBalance,
-		);
+		assert_eq!(CollatorSelection::candidates().len(), 2);
 	});
 }
 
 #[test]
-fn register_as_candidate_works() {
+fn cannot_become_candidate_if_invulnerable() {
 	new_test_ext().execute_with(|| {
-		// given
-		assert_eq!(CollatorSelection::desired_candidates(), 2);
-		assert_eq!(CollatorSelection::license_bond(), 10);
-		assert_eq!(CollatorSelection::candidates(), Vec::new());
 		assert_eq!(CollatorSelection::invulnerables(), vec![1, 2]);
 
-		// take two endowed, non-invulnerables accounts.
-		assert_eq!(Balances::free_balance(&3), 100);
-		assert_eq!(Balances::free_balance(&4), 100);
+		// can obtain a license even if is invulnerable.
+		assert_ok!(CollatorSelection::get_license(RuntimeOrigin::signed(1)));
+		// but cannot onboard
+		assert_noop!(
+			CollatorSelection::onboard(RuntimeOrigin::signed(1)),
+			Error::<Test>::AlreadyInvulnerable,
+		);
 
-		assert_ok!(CollatorSelection::register_as_candidate(
-			RuntimeOrigin::signed(3)
+		// get a license and then become invulnerable.
+		assert_ok!(CollatorSelection::get_license(RuntimeOrigin::signed(3)));
+		assert_ok!(CollatorSelection::add_invulnerable(
+			RuntimeOrigin::signed(RootAccount::get()),
+			3
 		));
-		assert_ok!(CollatorSelection::register_as_candidate(
-			RuntimeOrigin::signed(4)
+		assert_noop!(
+			CollatorSelection::onboard(RuntimeOrigin::signed(3)),
+			Error::<Test>::AlreadyInvulnerable,
+		);
+	})
+}
+
+#[test]
+fn can_become_invulnerable_if_candidate() {
+	new_test_ext().execute_with(|| {
+		// become a candidate and then become invulnerable.
+		get_license_and_onboard(3);
+		assert_eq!(CollatorSelection::candidates(), vec![3]);
+
+		assert_ok!(CollatorSelection::add_invulnerable(
+			RuntimeOrigin::signed(RootAccount::get()),
+			3
 		));
+		// should exclude from candidates, but not revoke the license
+		assert_eq!(CollatorSelection::candidates(), vec![]);
+		assert_eq!(CollatorSelection::licenses(3), 10);
+		assert_eq!(Balances::free_balance(3), 90);
+	});
+}
 
-		assert_eq!(Balances::free_balance(&3), 90);
-		assert_eq!(Balances::free_balance(&4), 90);
+#[test]
+fn offboard() {
+	new_test_ext().execute_with(|| {
+		// register a candidate.
+		get_license_and_onboard(3);
+		assert_eq!(Balances::free_balance(3), 90);
+
+		// cannot leave if holds license but not yet candidate.
+		assert_ok!(CollatorSelection::get_license(RuntimeOrigin::signed(4)));
+		assert_noop!(
+			CollatorSelection::offboard(RuntimeOrigin::signed(4)),
+			Error::<Test>::NotCandidate
+		);
+		// cannot leave if does not hold license.
+		assert_noop!(
+			CollatorSelection::offboard(RuntimeOrigin::signed(5)),
+			Error::<Test>::NotCandidate
+		);
 
-		assert_eq!(CollatorSelection::candidates().len(), 2);
+		// bond is returned - only after releasing the license
+		assert_ok!(CollatorSelection::offboard(RuntimeOrigin::signed(3)));
+		assert_eq!(Balances::free_balance(3), 90);
+		assert_eq!(CollatorSelection::last_authored_block(3), 0);
+		assert_ok!(CollatorSelection::release_license(RuntimeOrigin::signed(3)));
+		assert_eq!(Balances::free_balance(3), 100);
 	});
 }
 
 #[test]
-fn leave_intent() {
+fn release_license() {
 	new_test_ext().execute_with(|| {
+		// obtain a license to collate and reserve the bond.
+		assert_ok!(CollatorSelection::get_license(RuntimeOrigin::signed(3)));
+		assert_eq!(Balances::free_balance(3), 90);
+
+		// release the license and get the bond back.
+		assert_ok!(CollatorSelection::release_license(RuntimeOrigin::signed(3)));
+		assert_eq!(Balances::free_balance(3), 100);
+
 		// register a candidate.
-		assert_ok!(CollatorSelection::register_as_candidate(
-			RuntimeOrigin::signed(3)
-		));
+		get_license_and_onboard(3);
 		assert_eq!(Balances::free_balance(3), 90);
 
-		// register too so can leave above min candidates
-		assert_ok!(CollatorSelection::register_as_candidate(
-			RuntimeOrigin::signed(5)
-		));
-		assert_eq!(Balances::free_balance(5), 90);
+		// can release license even if onboarded.
+		assert_ok!(CollatorSelection::release_license(RuntimeOrigin::signed(3)));
+		assert_eq!(Balances::free_balance(3), 100);
+		assert_eq!(CollatorSelection::candidates(), vec![]);
+	});
+}
+
+#[test]
+fn force_revoke_license() {
+	new_test_ext().execute_with(|| {
+		// obtain a license to collate and reserve the bond.
+		assert_ok!(CollatorSelection::get_license(RuntimeOrigin::signed(3)));
+		assert_eq!(Balances::free_balance(3), 90);
 
-		// cannot leave if not candidate.
+		// cannot execute the operation as non-root
 		assert_noop!(
-			CollatorSelection::leave_intent(RuntimeOrigin::signed(4)),
-			Error::<Test>::NotCandidate
+			CollatorSelection::force_revoke_license(RuntimeOrigin::signed(3), 3),
+			BadOrigin
 		);
 
-		// bond is returned
-		assert_ok!(CollatorSelection::leave_intent(RuntimeOrigin::signed(3)));
+		// release the license and get the bond back.
+		assert_ok!(CollatorSelection::force_revoke_license(
+			RuntimeOrigin::signed(RootAccount::get()),
+			3
+		));
+		assert_eq!(Balances::free_balance(3), 100);
+
+		// register a candidate.
+		get_license_and_onboard(3);
+		assert_eq!(Balances::free_balance(3), 90);
+
+		// can release license even if onboarded.
+		assert_ok!(CollatorSelection::force_revoke_license(
+			RuntimeOrigin::signed(RootAccount::get()),
+			3
+		));
 		assert_eq!(Balances::free_balance(3), 100);
-		assert_eq!(CollatorSelection::last_authored_block(3), 0);
+		assert_eq!(CollatorSelection::candidates(), vec![]);
 	});
 }
 
@@ -325,18 +415,11 @@
 
 		// 4 is the default author.
 		assert_eq!(Balances::free_balance(4), 100);
-		assert_ok!(CollatorSelection::register_as_candidate(
-			RuntimeOrigin::signed(4)
-		));
+		get_license_and_onboard(4);
 		// triggers `note_author`
 		Authorship::on_initialize(1);
 
-		let collator = LicenseInfo {
-			who: 4,
-			deposit: 10,
-		};
-
-		assert_eq!(CollatorSelection::candidates(), vec![collator]);
+		assert_eq!(CollatorSelection::candidates(), vec![4]);
 		assert_eq!(CollatorSelection::last_authored_block(4), 0);
 
 		// half of the pot goes to the collator who's the author (4 in tests).
@@ -355,18 +438,11 @@
 		Balances::make_free_balance_be(&CollatorSelection::account_id(), 5);
 		// 4 is the default author.
 		assert_eq!(Balances::free_balance(4), 100);
-		assert_ok!(CollatorSelection::register_as_candidate(
-			RuntimeOrigin::signed(4)
-		));
+		get_license_and_onboard(4);
 		// triggers `note_author`
 		Authorship::on_initialize(1);
 
-		let collator = LicenseInfo {
-			who: 4,
-			deposit: 10,
-		};
-
-		assert_eq!(CollatorSelection::candidates(), vec![collator]);
+		assert_eq!(CollatorSelection::candidates(), vec![4]);
 		assert_eq!(CollatorSelection::last_authored_block(4), 0);
 		// Nothing received
 		assert_eq!(Balances::free_balance(4), 90);
@@ -389,9 +465,7 @@
 		assert_eq!(SessionHandlerCollators::get(), vec![1, 2]);
 
 		// add a new collator
-		assert_ok!(CollatorSelection::register_as_candidate(
-			RuntimeOrigin::signed(3)
-		));
+		get_license_and_onboard(5);
 
 		// session won't see this.
 		assert_eq!(SessionHandlerCollators::get(), vec![1, 2]);
@@ -410,7 +484,7 @@
 		initialize_to_block(20);
 		assert_eq!(SessionChangeBlock::get(), 20);
 		// changed are now reflected to session handlers.
-		assert_eq!(SessionHandlerCollators::get(), vec![1, 2, 3]);
+		assert_eq!(SessionHandlerCollators::get(), vec![1, 2, 5]);
 	});
 }
 
@@ -418,64 +492,28 @@
 fn kick_mechanism() {
 	new_test_ext().execute_with(|| {
 		// add a new collator
-		assert_ok!(CollatorSelection::register_as_candidate(
-			RuntimeOrigin::signed(3)
-		));
-		assert_ok!(CollatorSelection::register_as_candidate(
-			RuntimeOrigin::signed(4)
-		));
+		get_license_and_onboard(3);
+		get_license_and_onboard(4);
+
 		initialize_to_block(10);
 		assert_eq!(CollatorSelection::candidates().len(), 2);
+
 		initialize_to_block(20);
 		assert_eq!(SessionChangeBlock::get(), 20);
 		// 4 authored this block, gets to stay 3 was kicked
 		assert_eq!(CollatorSelection::candidates().len(), 1);
 		// 3 will be kicked after 1 session delay
 		assert_eq!(SessionHandlerCollators::get(), vec![1, 2, 3, 4]);
-		let collator = LicenseInfo {
-			who: 4,
-			deposit: 10,
-		};
-		assert_eq!(CollatorSelection::candidates(), vec![collator]);
-		assert_eq!(CollatorSelection::kick_threshold(), 1);
+
+		assert_eq!(CollatorSelection::candidates(), vec![4]);
+		assert_eq!(CollatorSelection::kick_threshold(), 10);
 		assert_eq!(CollatorSelection::last_authored_block(4), 20);
+
 		initialize_to_block(30);
 		// 3 gets kicked after 1 session delay
 		assert_eq!(SessionHandlerCollators::get(), vec![1, 2, 4]);
-		// kicked collator gets funds back
-		assert_eq!(Balances::free_balance(3), 100);
-	});
-}
-
-#[test]
-fn should_not_kick_mechanism_too_few() {
-	new_test_ext().execute_with(|| {
-		// add a new collator
-		assert_ok!(CollatorSelection::register_as_candidate(
-			RuntimeOrigin::signed(3)
-		));
-		assert_ok!(CollatorSelection::register_as_candidate(
-			RuntimeOrigin::signed(5)
-		));
-		initialize_to_block(10);
-		assert_eq!(CollatorSelection::candidates().len(), 2);
-		initialize_to_block(20);
-		assert_eq!(SessionChangeBlock::get(), 20);
-		// 4 authored this block, 5 gets to stay too few 3 was kicked
-		assert_eq!(CollatorSelection::candidates().len(), 1);
-		// 3 will be kicked after 1 session delay
-		assert_eq!(SessionHandlerCollators::get(), vec![1, 2, 3, 5]);
-		let collator = LicenseInfo {
-			who: 5,
-			deposit: 10,
-		};
-		assert_eq!(CollatorSelection::candidates(), vec![collator]);
-		assert_eq!(CollatorSelection::last_authored_block(4), 20);
-		initialize_to_block(30);
-		// 3 gets kicked after 1 session delay
-		assert_eq!(SessionHandlerCollators::get(), vec![1, 2, 5]);
-		// kicked collator gets funds back
-		assert_eq!(Balances::free_balance(3), 100);
+		// kicked collator gets their funds slashed, the deposit going to treasury
+		assert_eq!(Balances::free_balance(3), 90);
 	});
 }
 
@@ -489,9 +527,9 @@
 	let invulnerables = vec![1, 1];
 
 	let collator_selection = collator_selection::GenesisConfig::<Test> {
-		desired_candidates: 2,
+		desired_collators: 5,
 		license_bond: 10,
-		kick_threshold: 1,
+		kick_threshold: 10,
 		invulnerables,
 	};
 	// collator selection must be initialized before session.

--- a/pallets/collator-selection/src/weights.rs
+++ b/pallets/collator-selection/src/weights.rs
@@ -45,7 +45,7 @@
 // The weight info trait for `pallet_collator_selection`.
 pub trait WeightInfo {
 	fn set_invulnerables(_b: u32) -> Weight;
-	fn set_desired_candidates() -> Weight;
+	fn set_desired_collators() -> Weight;
 	fn set_license_bond() -> Weight;
 	fn register_as_candidate(_c: u32) -> Weight;
 	fn leave_intent(_c: u32) -> Weight;
@@ -62,7 +62,7 @@
 			.saturating_add(Weight::from_ref_time(68_000 as u64).saturating_mul(b as u64))
 			.saturating_add(T::DbWeight::get().writes(1 as u64))
 	}
-	fn set_desired_candidates() -> Weight {
+	fn set_desired_collators() -> Weight {
 		Weight::from_ref_time(16_363_000 as u64).saturating_add(T::DbWeight::get().writes(1 as u64))
 	}
 	fn set_license_bond() -> Weight {
@@ -108,7 +108,7 @@
 			.saturating_add(Weight::from_ref_time(68_000 as u64).saturating_mul(b as u64))
 			.saturating_add(RocksDbWeight::get().writes(1 as u64))
 	}
-	fn set_desired_candidates() -> Weight {
+	fn set_desired_collators() -> Weight {
 		Weight::from_ref_time(16_363_000 as u64)
 			.saturating_add(RocksDbWeight::get().writes(1 as u64))
 	}

--- a/primitives/common/src/constants.rs
+++ b/primitives/common/src/constants.rs
@@ -45,9 +45,9 @@
 /// Minimum balance required to create or keep an account open.
 pub const EXISTENTIAL_DEPOSIT: u128 = 0;
 /// Amount of Balance reserved for candidate registration.
-pub const GENESIS_LICENSE_BOND: u128 = EXISTENTIAL_DEPOSIT;
+pub const GENESIS_LICENSE_BOND: u128 = 1_000_000_000_000 * UNIQUE;
 /// How long a periodic session lasts in blocks.
-pub const SESSION_LENGTH: BlockNumber = MINUTES;
+pub const SESSION_LENGTH: BlockNumber = HOURS;
 
 // Targeting 0.1 UNQ per transfer
 pub const WEIGHT_TO_FEE_COEFF: u32 = /*<weight2fee>*/175_199_920/*</weight2fee>*/;

--- a/runtime/common/config/pallets/collator_selection.rs
+++ b/runtime/common/config/pallets/collator_selection.rs
@@ -55,9 +55,7 @@
 
 parameter_types! {
 	pub const PotId: PalletId = PalletId(*b"PotStake");
-	pub const MaxCandidates: u32 = 30; // todo:collator 30 collator slots - 3 planned invulnerables
-	pub const MinCandidates: u32 = 1;
-	pub const MaxInvulnerables: u32 = 30;
+	pub const MaxCollators: u32 = 10;
 	pub const SlashRatio: Perbill = Perbill::from_percent(100);
 }
 
@@ -68,9 +66,7 @@
 	type UpdateOrigin = EnsureRoot<AccountId>;
 	type TreasuryAccountId = TreasuryAccountId;
 	type PotId = PotId;
-	type MaxCandidates = MaxCandidates;
-	type MinCandidates = MinCandidates;
-	type MaxInvulnerables = MaxInvulnerables;
+	type MaxCollators = MaxCollators;
 	// todo:collator kick threshold should be in storage and configured only by root -- or rather UpdateOrigin
 	type SlashRatio = SlashRatio;
 	type ValidatorId = <Self as frame_system::Config>::AccountId;

--- a/runtime/common/tests/mod.rs
+++ b/runtime/common/tests/mod.rs
@@ -18,7 +18,7 @@
 use sp_core::{Public, Pair};
 use sp_std::vec;
 use up_common::types::AuraId;
-use crate::{GenesisConfig, ParachainInfoConfig, AuraConfig};
+use crate::{GenesisConfig, ParachainInfoConfig};
 
 pub mod xcm;
 
@@ -28,7 +28,61 @@
 		.public()
 }
 
+#[cfg(feature = "collator-selection")]
+fn new_test_ext(para_id: u32) -> sp_io::TestExternalities {
+	use sp_core::{sr25519};
+	use sp_runtime::traits::{IdentifyAccount, Verify};
+	use crate::{AccountId, Signature, SessionKeys, CollatorSelectionConfig, SessionConfig};
+
+	type AccountPublic = <Signature as Verify>::Signer;
+
+	fn get_account_id_from_seed<TPublic: Public>(seed: &str) -> AccountId
+	where
+		AccountPublic: From<<TPublic::Pair as Pair>::Public>,
+	{
+		AccountPublic::from(get_from_seed::<TPublic>(seed)).into_account()
+	}
+
+	let accounts = vec!["Alice", "Bob"];
+	let keys = accounts
+		.iter()
+		.map(|&acc| {
+			let account_id = get_account_id_from_seed::<sr25519::Public>(acc);
+			(
+				account_id.clone(),
+				account_id,
+				SessionKeys {
+					aura: get_from_seed::<AuraId>(acc),
+				},
+			)
+		})
+		.collect::<Vec<_>>();
+	let invulnerables = accounts
+		.iter()
+		.map(|acc| get_account_id_from_seed::<sr25519::Public>(acc))
+		.collect::<Vec<_>>();
+
+	let cfg = GenesisConfig {
+		collator_selection: CollatorSelectionConfig {
+			desired_collators: 2,
+			license_bond: 10,
+			kick_threshold: 10,
+			invulnerables,
+		},
+		session: SessionConfig { keys },
+		parachain_info: ParachainInfoConfig {
+			parachain_id: para_id.into(),
+		},
+		..GenesisConfig::default()
+	};
+
+	cfg.build_storage().unwrap().into()
+}
+
+#[cfg(not(feature = "collator-selection"))]
 fn new_test_ext(para_id: u32) -> sp_io::TestExternalities {
+	use crate::AuraConfig;
+
 	let cfg = GenesisConfig {
 		aura: AuraConfig {
 			authorities: vec![