parachains.rs

		type Event = ();
		type TransactionPayment = ();
		type DustRemoval = ();
		type TransferPayment = ();
		type ExistentialDeposit = ExistentialDeposit;
		type TransferFee = TransferFee;
		type CreationFee = CreationFee;
		type TransactionBaseFee = TransactionBaseFee;
		type TransactionByteFee = TransactionByteFee;
		type WeightToFee = ConvertInto;
	}

	srml_staking_reward_curve::build! {
		const REWARD_CURVE: PiecewiseLinear<'static> = curve!(
			min_inflation: 0_025_000,
			max_inflation: 0_100_000,
			ideal_stake: 0_500_000,
			falloff: 0_050_000,
			max_piece_count: 40,
			test_precision: 0_005_000,
		);
	}

	parameter_types! {
		pub const SessionsPerEra: sr_staking_primitives::SessionIndex = 6;
		pub const BondingDuration: staking::EraIndex = 28;
		pub const AttestationPeriod: BlockNumber = 100;
		pub const RewardCurve: &'static PiecewiseLinear<'static> = &REWARD_CURVE;
	}

	impl staking::Trait for Test {
		type OnRewardMinted = ();
		type CurrencyToVote = ();
		type Event = ();
		type Currency = balances::Module<Test>;
		type Slash = ();
		type Reward = ();
		type SessionsPerEra = SessionsPerEra;
		type BondingDuration = BondingDuration;
		type SessionInterface = Self;
		type Time = timestamp::Module<Test>;
		type RewardCurve = RewardCurve;
	}

	impl attestations::Trait for Test {
		type AttestationPeriod = AttestationPeriod;
		type ValidatorIdentities = ValidatorIdentities<Test>;
		type RewardAttestation = ();
	}

	impl Trait for Test {
		type Origin = Origin;
		type Call = Call;
		type ParachainCurrency = balances::Module<Test>;
	}

	type Parachains = Module<Test>;
	type System = system::Module<Test>;
	type RandomnessCollectiveFlip = randomness_collective_flip::Module<Test>;

	fn new_test_ext(parachains: Vec<(ParaId, Vec<u8>, Vec<u8>)>) -> TestExternalities<Blake2Hasher> {
		use staking::StakerStatus;
		use babe::AuthorityId as BabeAuthorityId;

		let mut t = system::GenesisConfig::default().build_storage::<Test>().unwrap();

		let authority_keys = [
			Sr25519Keyring::Alice,
			Sr25519Keyring::Bob,
			Sr25519Keyring::Charlie,
			Sr25519Keyring::Dave,
			Sr25519Keyring::Eve,
			Sr25519Keyring::Ferdie,
			Sr25519Keyring::One,
			Sr25519Keyring::Two,
		];

		// stashes are the index.
		let session_keys: Vec<_> = authority_keys.iter().enumerate()
			.map(|(i, _k)| (i as u64, UintAuthorityId(i as u64)))
			.collect();

		let authorities: Vec<_> = authority_keys.iter().map(|k| ValidatorId::from(k.public())).collect();
		let babe_authorities: Vec<_> = authority_keys.iter()
			.map(|k| BabeAuthorityId::from(k.public()))
			.map(|k| (k, 1))
			.collect();

		// controllers are the index + 1000
		let stakers: Vec<_> = (0..authority_keys.len()).map(|i| (
			i as u64,
			i as u64 + 1000,
			10_000,
			StakerStatus::<u64>::Validator,
		)).collect();

		let balances: Vec<_> = (0..authority_keys.len()).map(|i| (i as u64, 10_000_000)).collect();

		GenesisConfig::<Test> {
			parachains,
			authorities: authorities.clone(),
			_phdata: Default::default(),
		}.assimilate_storage(&mut t).unwrap();

		session::GenesisConfig::<Test> {
			keys: session_keys,
		}.assimilate_storage(&mut t).unwrap();

		babe::GenesisConfig {
			authorities: babe_authorities,
		}.assimilate_storage::<Test>(&mut t).unwrap();

		balances::GenesisConfig::<Test> {
			balances,
			vesting: vec![],
		}.assimilate_storage(&mut t).unwrap();

		staking::GenesisConfig::<Test> {
			current_era: 0,
			stakers,
			validator_count: 10,
			minimum_validator_count: 8,
			invulnerables: vec![],
			.. Default::default()
		}.assimilate_storage(&mut t).unwrap();

		t.into()
	}

	fn set_heads(v: Vec<AttestedCandidate>) -> ParachainsCall<Test> {
		ParachainsCall::set_heads(v)
	}

	fn make_attestations(candidate: &mut AttestedCandidate) {
		let mut vote_implicit = false;
		let parent_hash = crate::System::parent_hash();

		let (duty_roster, _) = Parachains::calculate_duty_roster();
		let candidate_hash = candidate.candidate.hash();

		let authorities = Parachains::authorities();
		let extract_key = |public: ValidatorId| {
			let mut raw_public = [0; 32];
			raw_public.copy_from_slice(public.as_ref());
			Sr25519Keyring::from_raw_public(raw_public).unwrap()
		};

		let validation_entries = duty_roster.validator_duty.iter()
			.enumerate();

		let mut validator_indices = BitVec::new();
		for (idx, &duty) in validation_entries {
			if duty != Chain::Parachain(candidate.parachain_index()) { continue }
			vote_implicit = !vote_implicit;

			let key = extract_key(authorities[idx].clone());

			let statement = if vote_implicit {
				Statement::Candidate(candidate.candidate.clone())
			} else {
				Statement::Valid(candidate_hash.clone())
			};

			let payload = localized_payload(statement, parent_hash);
			let signature = key.sign(&payload[..]).into();

			candidate.validity_votes.push(if vote_implicit {
				ValidityAttestation::Implicit(signature)
			} else {
				ValidityAttestation::Explicit(signature)
			});

			if validator_indices.len() <= idx {
				validator_indices.resize(idx + 1, false);
			}
			validator_indices.set(idx, true);
		}
		candidate.validator_indices = validator_indices;
	}

	fn new_candidate_with_egress_roots(egress_queue_roots: Vec<(ParaId, H256)>) -> AttestedCandidate {
		AttestedCandidate {
			validity_votes: vec![],
			validator_indices: BitVec::new(),
			candidate: CandidateReceipt {
				parachain_index: 0.into(),
				collator: Default::default(),
				signature: Default::default(),
				head_data: HeadData(vec![1, 2, 3]),
				egress_queue_roots,
				fees: 0,
				block_data_hash: Default::default(),
				upward_messages: vec![],
			}
		}
	}

	fn new_candidate_with_upward_messages(
		id: u32,
		upward_messages: Vec<(ParachainDispatchOrigin, Vec<u8>)>
	) -> AttestedCandidate {
		AttestedCandidate {
			validity_votes: vec![],
			validator_indices: BitVec::new(),
			candidate: CandidateReceipt {
				parachain_index: id.into(),
				collator: Default::default(),
				signature: Default::default(),
				head_data: HeadData(vec![1, 2, 3]),
				egress_queue_roots: vec![],
				fees: 0,
				block_data_hash: Default::default(),
				upward_messages: upward_messages.into_iter()
					.map(|x| UpwardMessage { origin: x.0, data: x.1 })
					.collect(),
			}
		}
	}

	#[test]
	fn check_dispatch_upward_works() {
		let parachains = vec![
			(0u32.into(), vec![], vec![]),
			(1u32.into(), vec![], vec![]),
			(2u32.into(), vec![], vec![]),
		];
		with_externalities(&mut new_test_ext(parachains.clone()), || {
			let parachains = vec![0.into(), 1.into(), 2.into()];
			Parachains::queue_upward_messages(0.into(), &vec![
				UpwardMessage { origin: ParachainDispatchOrigin::Parachain, data: vec![0; 4] }
			]);
			Parachains::queue_upward_messages(1.into(), &vec![
				UpwardMessage { origin: ParachainDispatchOrigin::Parachain, data: vec![1; 4] }
			]);
			let mut dispatched: Vec<(ParaId, ParachainDispatchOrigin, Vec<u8>)> = vec![];
			let dummy = |id, origin, data: &[u8]| dispatched.push((id, origin, data.to_vec()));
			Parachains::dispatch_upward_messages(0, &parachains, 2, 3, dummy);
			assert_eq!(dispatched, vec![
				(0.into(), ParachainDispatchOrigin::Parachain, vec![0; 4])
			]);
			assert!(<RelayDispatchQueue>::get(ParaId::from(0)).is_empty());
			assert_eq!(<RelayDispatchQueue>::get(ParaId::from(1)).len(), 1);
		});
		with_externalities(&mut new_test_ext(parachains.clone()), || {
			let parachains = vec![0.into(), 1.into(), 2.into()];
			Parachains::queue_upward_messages(0.into(), &vec![
				UpwardMessage { origin: ParachainDispatchOrigin::Parachain, data: vec![0; 2] }
			]);
			Parachains::queue_upward_messages(1.into(), &vec![
				UpwardMessage { origin: ParachainDispatchOrigin::Parachain, data: vec![1; 2] }
			]);
			Parachains::queue_upward_messages(2.into(), &vec![
				UpwardMessage { origin: ParachainDispatchOrigin::Parachain, data: vec![2] }
			]);
			let mut dispatched: Vec<(ParaId, ParachainDispatchOrigin, Vec<u8>)> = vec![];
			let dummy = |id, origin, data: &[u8]| dispatched.push((id, origin, data.to_vec()));
			Parachains::dispatch_upward_messages(0, &parachains, 2, 3, dummy);
			assert_eq!(dispatched, vec![
				(0.into(), ParachainDispatchOrigin::Parachain, vec![0; 2]),
				(2.into(), ParachainDispatchOrigin::Parachain, vec![2])
			]);
			assert!(<RelayDispatchQueue>::get(ParaId::from(0)).is_empty());
			assert_eq!(<RelayDispatchQueue>::get(ParaId::from(1)).len(), 1);
			assert!(<RelayDispatchQueue>::get(ParaId::from(2)).is_empty());
		});
		with_externalities(&mut new_test_ext(parachains.clone()), || {
			let parachains = vec![0.into(), 1.into(), 2.into()];
			Parachains::queue_upward_messages(0.into(), &vec![
				UpwardMessage { origin: ParachainDispatchOrigin::Parachain, data: vec![0; 2] }
			]);
			Parachains::queue_upward_messages(1.into(), &vec![
				UpwardMessage { origin: ParachainDispatchOrigin::Parachain, data: vec![1; 2] }
			]);
			Parachains::queue_upward_messages(2.into(), &vec![
				UpwardMessage { origin: ParachainDispatchOrigin::Parachain, data: vec![2] }
			]);
			let mut dispatched: Vec<(ParaId, ParachainDispatchOrigin, Vec<u8>)> = vec![];
			let dummy = |id, origin, data: &[u8]| dispatched.push((id, origin, data.to_vec()));
			Parachains::dispatch_upward_messages(1, &parachains, 2, 3, dummy);
			assert_eq!(dispatched, vec![
				(1.into(), ParachainDispatchOrigin::Parachain, vec![1; 2]),
				(2.into(), ParachainDispatchOrigin::Parachain, vec![2])
			]);
			assert_eq!(<RelayDispatchQueue>::get(ParaId::from(0)).len(), 1);
			assert!(<RelayDispatchQueue>::get(ParaId::from(1)).is_empty());
			assert!(<RelayDispatchQueue>::get(ParaId::from(2)).is_empty());
		});
		with_externalities(&mut new_test_ext(parachains.clone()), || {
			let parachains = vec![0.into(), 1.into(), 2.into()];
			Parachains::queue_upward_messages(0.into(), &vec![
				UpwardMessage { origin: ParachainDispatchOrigin::Parachain, data: vec![0; 2] }
			]);
			Parachains::queue_upward_messages(1.into(), &vec![
				UpwardMessage { origin: ParachainDispatchOrigin::Parachain, data: vec![1; 2] }
			]);
			Parachains::queue_upward_messages(2.into(), &vec![
				UpwardMessage { origin: ParachainDispatchOrigin::Parachain, data: vec![2] }
			]);
			let mut dispatched: Vec<(ParaId, ParachainDispatchOrigin, Vec<u8>)> = vec![];
			let dummy = |id, origin, data: &[u8]| dispatched.push((id, origin, data.to_vec()));
			Parachains::dispatch_upward_messages(2, &parachains, 2, 3, dummy);
			assert_eq!(dispatched, vec![
				(2.into(), ParachainDispatchOrigin::Parachain, vec![2]),
				(0.into(), ParachainDispatchOrigin::Parachain, vec![0; 2])
			]);
			assert!(<RelayDispatchQueue>::get(ParaId::from(0)).is_empty());
			assert_eq!(<RelayDispatchQueue>::get(ParaId::from(1)).len(), 1);
			assert!(<RelayDispatchQueue>::get(ParaId::from(2)).is_empty());
		});
	}

	#[test]
	fn check_queue_upward_messages_works() {
		let parachains = vec![
			(0u32.into(), vec![], vec![]),
		];
		with_externalities(&mut new_test_ext(parachains), || {
			let messages = vec![
				UpwardMessage { origin: ParachainDispatchOrigin::Signed, data: vec![0] }
			];
			assert_ok!(Parachains::check_upward_messages(0.into(), &messages, 2, 3));

			// all good.
			Parachains::queue_upward_messages(0.into(), &vec![
				UpwardMessage { origin: ParachainDispatchOrigin::Signed, data: vec![0] },
			]);
			let messages = vec![
				UpwardMessage { origin: ParachainDispatchOrigin::Parachain, data: vec![1, 2] }
			];
			assert_ok!(Parachains::check_upward_messages(0.into(), &messages, 2, 3));
			Parachains::queue_upward_messages(0.into(), &messages);
			assert_eq!(<RelayDispatchQueue>::get(ParaId::from(0)), vec![
				UpwardMessage { origin: ParachainDispatchOrigin::Signed, data: vec![0] },
				UpwardMessage { origin: ParachainDispatchOrigin::Parachain, data: vec![1, 2] },
			]);
		});
	}

	#[test]
	fn check_queue_full_upward_messages_fails() {
		let parachains = vec![
			(0u32.into(), vec![], vec![]),
		];
		with_externalities(&mut new_test_ext(parachains), || {
			// oversize, but ok since it's just one and the queue is empty.
			let messages = vec![
				UpwardMessage { origin: ParachainDispatchOrigin::Signed, data: vec![0; 4] },
			];
			assert_ok!(Parachains::check_upward_messages(0.into(), &messages, 2, 3));

			// oversize and bad since it's not just one.
			let messages = vec![
				UpwardMessage { origin: ParachainDispatchOrigin::Signed, data: vec![0] },
				UpwardMessage { origin: ParachainDispatchOrigin::Signed, data: vec![0; 4] },
			];
			assert_err!(
				Parachains::check_upward_messages(0.into(), &messages, 2, 3),
				"Messages added when queue full"
			);

			// too many messages.
			let messages = vec![
				UpwardMessage { origin: ParachainDispatchOrigin::Signed, data: vec![0] },
				UpwardMessage { origin: ParachainDispatchOrigin::Signed, data: vec![1] },
				UpwardMessage { origin: ParachainDispatchOrigin::Signed, data: vec![2] },
			];
			assert_err!(
				Parachains::check_upward_messages(0.into(), &messages, 2, 3),
				"Messages added when queue full"
			);
		});
	}

	#[test]
	fn check_queued_too_many_upward_messages_fails() {
		let parachains = vec![
			(0u32.into(), vec![], vec![]),
		];
		with_externalities(&mut new_test_ext(parachains), || {
			// too many messages.
			Parachains::queue_upward_messages(0.into(), &vec![
				UpwardMessage { origin: ParachainDispatchOrigin::Signed, data: vec![0] },
			]);
			let messages = vec![
				UpwardMessage { origin: ParachainDispatchOrigin::Signed, data: vec![1] },
				UpwardMessage { origin: ParachainDispatchOrigin::Signed, data: vec![2] },
			];
			assert_err!(
				Parachains::check_upward_messages(0.into(), &messages, 2, 3),
				"Messages added when queue full"
			);
		});
	}

	#[test]
	fn check_queued_total_oversize_upward_messages_fails() {
		let parachains = vec![
			(0u32.into(), vec![], vec![]),
		];
		with_externalities(&mut new_test_ext(parachains), || {
			// too much data.
			Parachains::queue_upward_messages(0.into(), &vec![
				UpwardMessage { origin: ParachainDispatchOrigin::Signed, data: vec![0, 1] },
			]);
			let messages = vec![
				UpwardMessage { origin: ParachainDispatchOrigin::Signed, data: vec![2, 3] },
			];
			assert_err!(
				Parachains::check_upward_messages(0.into(), &messages, 2, 3),
				"Messages added when queue full"
			);
		});
	}

	#[test]
	fn check_queued_pre_jumbo_upward_messages_fails() {
		let parachains = vec![
			(0u32.into(), vec![], vec![]),
		];
		with_externalities(&mut new_test_ext(parachains), || {
			// bad - already an oversize messages queued.
			Parachains::queue_upward_messages(0.into(), &vec![
				UpwardMessage { origin: ParachainDispatchOrigin::Signed, data: vec![0; 4] },
			]);
			let messages = vec![
				UpwardMessage { origin: ParachainDispatchOrigin::Signed, data: vec![0] }
			];
			assert_err!(
				Parachains::check_upward_messages(0.into(), &messages, 2, 3),
				"Messages added when queue full"
			);
		});
	}

	#[test]
	fn check_queued_post_jumbo_upward_messages_fails() {
		let parachains = vec![
			(0u32.into(), vec![], vec![]),
		];
		with_externalities(&mut new_test_ext(parachains), || {
			// bad - oversized and already a message queued.
			Parachains::queue_upward_messages(0.into(), &vec![
				UpwardMessage { origin: ParachainDispatchOrigin::Signed, data: vec![0] },
			]);
			let messages = vec![
				UpwardMessage { origin: ParachainDispatchOrigin::Signed, data: vec![0; 4] }
			];
			assert_err!(
				Parachains::check_upward_messages(0.into(), &messages, 2, 3),
				"Messages added when queue full"
			);
		});
	}

	#[test]
	fn upward_queuing_works() {
		// That the list of egress queue roots is in ascending order by `ParaId`.
		let parachains = vec![
			(0u32.into(), vec![], vec![]),
			(1u32.into(), vec![], vec![]),
		];

		with_externalities(&mut new_test_ext(parachains), || {
			// parachain 0 is self
			let mut candidates = vec![
				new_candidate_with_upward_messages(0, vec![
					(ParachainDispatchOrigin::Signed, vec![1]),
				]),
				new_candidate_with_upward_messages(1, vec![
					(ParachainDispatchOrigin::Parachain, vec![2]),
				])
			];
			candidates.iter_mut().for_each(make_attestations);

			assert_ok!(Parachains::dispatch(
				set_heads(candidates),
				Origin::NONE,
			));

			assert!(<RelayDispatchQueue>::get(ParaId::from(0)).is_empty());
			assert!(<RelayDispatchQueue>::get(ParaId::from(1)).is_empty());
		});
	}

	#[test]
	fn active_parachains_should_work() {
		let parachains = vec![
			(5u32.into(), vec![1,2,3], vec![1]),
			(100u32.into(), vec![4,5,6], vec![2]),
		];

		with_externalities(&mut new_test_ext(parachains), || {
			assert_eq!(Parachains::active_parachains(), vec![5u32.into(), 100u32.into()]);
			assert_eq!(Parachains::parachain_code(ParaId::from(5u32)), Some(vec![1,2,3]));
			assert_eq!(Parachains::parachain_code(ParaId::from(100u32)), Some(vec![4,5,6]));
		});
	}

	#[test]
	fn register_deregister() {
		let parachains = vec![
			(5u32.into(), vec![1,2,3], vec![1]),
			(100u32.into(), vec![4,5,6], vec![2,]),
		];

		with_externalities(&mut new_test_ext(parachains), || {
			assert_eq!(Parachains::active_parachains(), vec![5u32.into(), 100u32.into()]);

			assert_eq!(Parachains::parachain_code(ParaId::from(5u32)), Some(vec![1,2,3]));
			assert_eq!(Parachains::parachain_code(ParaId::from(100u32)), Some(vec![4,5,6]));

			assert_ok!(Parachains::register_parachain(Origin::ROOT, 99u32.into(), vec![7,8,9], vec![1, 1, 1]));

			assert_eq!(Parachains::active_parachains(), vec![5u32.into(), 99u32.into(), 100u32.into()]);
			assert_eq!(Parachains::parachain_code(ParaId::from(99u32)), Some(vec![7,8,9]));

			assert_ok!(Parachains::deregister_parachain(Origin::ROOT, 5u32.into()));

			assert_eq!(Parachains::active_parachains(), vec![99u32.into(), 100u32.into()]);
			assert_eq!(Parachains::parachain_code(ParaId::from(5u32)), None);
		});
	}

	#[test]
	fn duty_roster_works() {
		let parachains = vec![
			(0u32.into(), vec![], vec![]),
			(1u32.into(), vec![], vec![]),
		];

		with_externalities(&mut new_test_ext(parachains), || {
			let check_roster = |duty_roster: &DutyRoster| {
				assert_eq!(duty_roster.validator_duty.len(), 8);
				for i in (0..2).map(ParaId::from) {
					assert_eq!(duty_roster.validator_duty.iter().filter(|&&j| j == Chain::Parachain(i)).count(), 3);
				}
				assert_eq!(duty_roster.validator_duty.iter().filter(|&&j| j == Chain::Relay).count(), 2);
			};

			let duty_roster_0 = Parachains::calculate_duty_roster().0;
			check_roster(&duty_roster_0);

			System::initialize(&1, &H256::from([1; 32]), &Default::default(), &Default::default());
			RandomnessCollectiveFlip::on_initialize(1);
			let duty_roster_1 = Parachains::calculate_duty_roster().0;
			check_roster(&duty_roster_1);
			assert_ne!(duty_roster_0, duty_roster_1);


			System::initialize(&2, &H256::from([2; 32]), &Default::default(), &Default::default());
			RandomnessCollectiveFlip::on_initialize(2);
			let duty_roster_2 = Parachains::calculate_duty_roster().0;
			check_roster(&duty_roster_2);
			assert_ne!(duty_roster_0, duty_roster_2);
			assert_ne!(duty_roster_1, duty_roster_2);
		});
	}

	#[test]
	fn unattested_candidate_is_rejected() {
		let parachains = vec![
			(0u32.into(), vec![], vec![]),
			(1u32.into(), vec![], vec![]),
		];

		with_externalities(&mut new_test_ext(parachains), || {
			let candidate = AttestedCandidate {
				validity_votes: vec![],
				validator_indices: BitVec::new(),
				candidate: CandidateReceipt {
					parachain_index: 0.into(),
					collator: Default::default(),
					signature: Default::default(),
					head_data: HeadData(vec![1, 2, 3]),
					egress_queue_roots: vec![],
					fees: 0,
					block_data_hash: Default::default(),
					upward_messages: vec![],
				},

			};

			assert!(Parachains::dispatch(set_heads(vec![candidate]), Origin::NONE).is_err());
		})
	}

	#[test]
	fn attested_candidates_accepted_in_order() {
		let parachains = vec![
			(0u32.into(), vec![], vec![]),
			(1u32.into(), vec![], vec![]),
		];

		with_externalities(&mut new_test_ext(parachains), || {
			let mut candidate_a = AttestedCandidate {
				validity_votes: vec![],
				validator_indices: BitVec::new(),
				candidate: CandidateReceipt {
					parachain_index: 0.into(),
					collator: Default::default(),
					signature: Default::default(),
					head_data: HeadData(vec![1, 2, 3]),
					egress_queue_roots: vec![],
					fees: 0,
					block_data_hash: Default::default(),
					upward_messages: vec![],
				}
			};

			let mut candidate_b = AttestedCandidate {
				validity_votes: vec![],
				validator_indices: BitVec::new(),
				candidate: CandidateReceipt {
					parachain_index: 1.into(),
					collator: Default::default(),
					signature: Default::default(),
					head_data: HeadData(vec![2, 3, 4]),
					egress_queue_roots: vec![],
					fees: 0,
					block_data_hash: Default::default(),
					upward_messages: vec![],
				}
			};

			make_attestations(&mut candidate_a);
			make_attestations(&mut candidate_b);

			assert!(Parachains::dispatch(
				set_heads(vec![candidate_b.clone(), candidate_a.clone()]),
				Origin::NONE,
			).is_err());

			assert_ok!(Parachains::dispatch(
				set_heads(vec![candidate_a.clone(), candidate_b.clone()]),
				Origin::NONE,
			));
		});
	}

	#[test]
	fn duplicate_vote_is_rejected() {
		let parachains = vec![
			(0u32.into(), vec![], vec![]),
			(1u32.into(), vec![], vec![]),
		];

		with_externalities(&mut new_test_ext(parachains), || {
			let mut candidate = AttestedCandidate {
				validity_votes: vec![],
				validator_indices: BitVec::new(),
				candidate: CandidateReceipt {
					parachain_index: 0.into(),
					collator: Default::default(),
					signature: Default::default(),
					head_data: HeadData(vec![1, 2, 3]),
					egress_queue_roots: vec![],
					fees: 0,
					block_data_hash: Default::default(),
					upward_messages: vec![],
				}
			};

			make_attestations(&mut candidate);

			let mut double_validity = candidate.clone();
			double_validity.validity_votes.push(candidate.validity_votes[0].clone());
			double_validity.validator_indices.push(true);

			assert!(Parachains::dispatch(
				set_heads(vec![double_validity]),
				Origin::NONE,
			).is_err());
		});
	}

	#[test]
	fn validators_not_from_group_is_rejected() {
		let parachains = vec![
			(0u32.into(), vec![], vec![]),
			(1u32.into(), vec![], vec![]),
		];

		with_externalities(&mut new_test_ext(parachains), || {
			let mut candidate = AttestedCandidate {
				validity_votes: vec![],
				validator_indices: BitVec::new(),
				candidate: CandidateReceipt {
					parachain_index: 0.into(),
					collator: Default::default(),
					signature: Default::default(),
					head_data: HeadData(vec![1, 2, 3]),
					egress_queue_roots: vec![],
					fees: 0,
					block_data_hash: Default::default(),
					upward_messages: vec![],
				}
			};

			make_attestations(&mut candidate);

			// Change the last vote index to make it not corresponding to the assigned group.
			assert!(candidate.validator_indices.pop().is_some());
			candidate.validator_indices.append(&mut bitvec![0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1]);

			assert!(Parachains::dispatch(
				set_heads(vec![candidate]),
				Origin::NONE,
			).is_err());
		});
	}

	#[test]
	fn ingress_works() {
		use sr_primitives::traits::OnFinalize;

		let parachains = vec![
			(0u32.into(), vec![], vec![]),
			(1u32.into(), vec![], vec![]),
			(99u32.into(), vec![1, 2, 3], vec![4, 5, 6]),
		];

		with_externalities(&mut new_test_ext(parachains), || {
			assert_eq!(Parachains::ingress(ParaId::from(1), None), Some(Vec::new()));
			assert_eq!(Parachains::ingress(ParaId::from(99), None), Some(Vec::new()));

			for i in 1..10 {
				System::set_block_number(i);

				let from_a = vec![(1.into(), [i as u8; 32].into())];
				let mut candidate_a = AttestedCandidate {
					validity_votes: vec![],
					validator_indices: BitVec::new(),
					candidate: CandidateReceipt {
						parachain_index: 0.into(),
						collator: Default::default(),
						signature: Default::default(),
						head_data: HeadData(vec![1, 2, 3]),
						egress_queue_roots: from_a.clone(),
						fees: 0,
						block_data_hash: Default::default(),
						upward_messages: vec![],
					}
				};

				let from_b = vec![(99.into(), [i as u8; 32].into())];
				let mut candidate_b = AttestedCandidate {
					validity_votes: vec![],
					validator_indices: BitVec::new(),
					candidate: CandidateReceipt {
						parachain_index: 1.into(),
						collator: Default::default(),
						signature: Default::default(),
						head_data: HeadData(vec![1, 2, 3]),
						egress_queue_roots: from_b.clone(),
						fees: 0,
						block_data_hash: Default::default(),
						upward_messages: vec![],
					}
				};

				make_attestations(&mut candidate_a);
				make_attestations(&mut candidate_b);

				assert_ok!(Parachains::dispatch(
					set_heads(vec![candidate_a, candidate_b]),
					Origin::NONE,
				));

				Parachains::on_finalize(i);
			}

			System::set_block_number(10);
			assert_ok!(Parachains::dispatch(
				set_heads(vec![]),
				Origin::NONE,
			));

			// parachain 1 has had a bunch of parachain candidates included,
			// which raises the watermark.
			assert_eq!(
				Parachains::ingress(ParaId::from(1), None),
				Some(vec![
					(9, BlockIngressRoots(vec![
						(0.into(), [9; 32].into())
					]))
				]),
			);

			// parachain 99 hasn't had any candidates included, so the
			// ingress is piling up.
			assert_eq!(
				Parachains::ingress(ParaId::from(99), None),
				Some((1..10).map(|i| (i, BlockIngressRoots(
					vec![(1.into(), [i as u8; 32].into())]
				))).collect::<Vec<_>>()),
			);

			assert_ok!(Parachains::deregister_parachain(Origin::ROOT, 1u32.into()));

			// after deregistering, there is no ingress to 1, but unrouted messages
			// from 1 stick around.
			assert_eq!(Parachains::ingress(ParaId::from(1), None), None);
			assert_eq!(Parachains::ingress(ParaId::from(99), None), Some((1..10).map(|i| (i, BlockIngressRoots(
				vec![(1.into(), [i as u8; 32].into())]
			))).collect::<Vec<_>>()));

			Parachains::on_finalize(10);
			System::set_block_number(11);

			let mut candidate_c = AttestedCandidate {
				validity_votes: vec![],
				validator_indices: BitVec::new(),
				candidate: CandidateReceipt {
					parachain_index: 99.into(),
					collator: Default::default(),
					signature: Default::default(),
					head_data: HeadData(vec![1, 2, 3]),
					egress_queue_roots: Vec::new(),
					fees: 0,
					block_data_hash: Default::default(),
					upward_messages: vec![],
				}
			};
			make_attestations(&mut candidate_c);

			assert_ok!(Parachains::dispatch(
				set_heads(vec![candidate_c]),
				Origin::NONE,
			));

			Parachains::on_finalize(11);
			System::set_block_number(12);

			// at the next block, ingress to 99 should be empty.
			assert_eq!(Parachains::ingress(ParaId::from(99), None), Some(Vec::new()));
		});
	}

	#[test]
	fn egress_routed_to_non_existent_parachain_is_rejected() {
		// That no parachain is routed to which doesn't exist
		let parachains = vec![
			(0u32.into(), vec![], vec![]),
			(1u32.into(), vec![], vec![]),
		];

		with_externalities(&mut new_test_ext(parachains), || {
			// parachain 99 does not exist
			let non_existent = vec![(99.into(), [1; 32].into())];
			let mut candidate = new_candidate_with_egress_roots(non_existent);

			make_attestations(&mut candidate);

			let result = Parachains::dispatch(
				set_heads(vec![candidate.clone()]),
				Origin::NONE,
			);

			assert_eq!(Err("Routing to non-existent parachain"), result);
		});
	}

	#[test]
	fn egress_routed_to_self_is_rejected() {
		// That the parachain doesn't route to self
		let parachains = vec![
			(0u32.into(), vec![], vec![]),
			(1u32.into(), vec![], vec![]),
		];

		with_externalities(&mut new_test_ext(parachains), || {
			// parachain 0 is self
			let to_self = vec![(0.into(), [1; 32].into())];
			let mut candidate = new_candidate_with_egress_roots(to_self);

			make_attestations(&mut candidate);

			let result = Parachains::dispatch(
				set_heads(vec![candidate.clone()]),
				Origin::NONE,
			);

			assert_eq!(Err("Parachain routing to self"), result);
		});
	}

	#[test]
	fn egress_queue_roots_out_of_order_rejected() {
		// That the list of egress queue roots is in ascending order by `ParaId`.
		let parachains = vec![
			(0u32.into(), vec![], vec![]),
			(1u32.into(), vec![], vec![]),
		];

		with_externalities(&mut new_test_ext(parachains), || {
			// parachain 0 is self
			let out_of_order = vec![(1.into(), [1; 32].into()), ((0.into(), [1; 32].into()))];
			let mut candidate = new_candidate_with_egress_roots(out_of_order);

			make_attestations(&mut candidate);

			let result = Parachains::dispatch(
				set_heads(vec![candidate.clone()]),
				Origin::NONE,
			);

			assert_eq!(Err("Egress routes out of order by ID"), result);
		});
	}

	#[test]
	fn egress_queue_roots_empty_trie_roots_rejected() {
		let parachains = vec![
			(0u32.into(), vec![], vec![]),
			(1u32.into(), vec![], vec![]),
			(2u32.into(), vec![], vec![]),
		];

		with_externalities(&mut new_test_ext(parachains), || {
			// parachain 0 is self
			let contains_empty_trie_root = vec![(1.into(), [1; 32].into()), ((2.into(), EMPTY_TRIE_ROOT.into()))];
			let mut candidate = new_candidate_with_egress_roots(contains_empty_trie_root);

			make_attestations(&mut candidate);

			let result = Parachains::dispatch(
				set_heads(vec![candidate.clone()]),
				Origin::NONE,
			);

			assert_eq!(Err("Empty trie root included"), result);
		});
	}

	#[test]
	fn empty_trie_root_const_is_blake2_hashed_null_node() {
		let hashed_null_node =  <NodeCodec<Blake2Hasher> as trie_db::NodeCodec<Blake2Hasher>>::hashed_null_node();
		assert_eq!(hashed_null_node, EMPTY_TRIE_ROOT.into())
	}
}