lib.rs

					lane_id: TEST_LANE_ID,
					nonce: message_nonce
				}),
				topics: vec![],
			}],
		);

		weight
	}

	fn receive_messages_delivery_proof() {
		System::<TestRuntime>::set_block_number(1);
		System::<TestRuntime>::reset_events();

		assert_ok!(Pallet::<TestRuntime>::receive_messages_delivery_proof(
			RuntimeOrigin::signed(1),
			TestMessagesDeliveryProof(Ok((
				TEST_LANE_ID,
				InboundLaneData {
					last_confirmed_nonce: 1,
					relayers: vec![UnrewardedRelayer {
						relayer: 0,
						messages: DeliveredMessages::new(1, true),
					}]
					.into_iter()
					.collect(),
				},
			))),
			UnrewardedRelayersState {
				unrewarded_relayer_entries: 1,
				total_messages: 1,
				last_delivered_nonce: 1,
				..Default::default()
			},
		));

		assert_eq!(
			System::<TestRuntime>::events(),
			vec![EventRecord {
				phase: Phase::Initialization,
				event: TestEvent::Messages(Event::MessagesDelivered {
					lane_id: TEST_LANE_ID,
					messages: DeliveredMessages::new(1, true),
				}),
				topics: vec![],
			}],
		);
	}

	#[test]
	fn pallet_rejects_transactions_if_halted() {
		run_test(|| {
			// send message first to be able to check that delivery_proof fails later
			send_regular_message();

			PalletOperatingMode::<TestRuntime, ()>::put(MessagesOperatingMode::Basic(
				BasicOperatingMode::Halted,
			));

			assert_noop!(
				send_message::<TestRuntime, ()>(
					RuntimeOrigin::signed(1),
					TEST_LANE_ID,
					REGULAR_PAYLOAD,
				),
				Error::<TestRuntime, ()>::NotOperatingNormally,
			);

			assert_noop!(
				Pallet::<TestRuntime>::receive_messages_proof(
					RuntimeOrigin::signed(1),
					TEST_RELAYER_A,
					Ok(vec![message(2, REGULAR_PAYLOAD)]).into(),
					1,
					REGULAR_PAYLOAD.declared_weight,
				),
				Error::<TestRuntime, ()>::BridgeModule(bp_runtime::OwnedBridgeModuleError::Halted),
			);

			assert_noop!(
				Pallet::<TestRuntime>::receive_messages_delivery_proof(
					RuntimeOrigin::signed(1),
					TestMessagesDeliveryProof(Ok((
						TEST_LANE_ID,
						InboundLaneData {
							last_confirmed_nonce: 1,
							relayers: vec![unrewarded_relayer(1, 1, TEST_RELAYER_A)]
								.into_iter()
								.collect(),
						},
					))),
					UnrewardedRelayersState {
						unrewarded_relayer_entries: 1,
						messages_in_oldest_entry: 1,
						total_messages: 1,
						last_delivered_nonce: 1,
					},
				),
				Error::<TestRuntime, ()>::BridgeModule(bp_runtime::OwnedBridgeModuleError::Halted),
			);
		});
	}

	#[test]
	fn pallet_rejects_new_messages_in_rejecting_outbound_messages_operating_mode() {
		run_test(|| {
			// send message first to be able to check that delivery_proof fails later
			send_regular_message();

			PalletOperatingMode::<TestRuntime, ()>::put(
				MessagesOperatingMode::RejectingOutboundMessages,
			);

			assert_noop!(
				send_message::<TestRuntime, ()>(
					RuntimeOrigin::signed(1),
					TEST_LANE_ID,
					REGULAR_PAYLOAD,
				),
				Error::<TestRuntime, ()>::NotOperatingNormally,
			);

			assert_ok!(Pallet::<TestRuntime>::receive_messages_proof(
				RuntimeOrigin::signed(1),
				TEST_RELAYER_A,
				Ok(vec![message(1, REGULAR_PAYLOAD)]).into(),
				1,
				REGULAR_PAYLOAD.declared_weight,
			),);

			assert_ok!(Pallet::<TestRuntime>::receive_messages_delivery_proof(
				RuntimeOrigin::signed(1),
				TestMessagesDeliveryProof(Ok((
					TEST_LANE_ID,
					InboundLaneData {
						last_confirmed_nonce: 1,
						relayers: vec![unrewarded_relayer(1, 1, TEST_RELAYER_A)]
							.into_iter()
							.collect(),
					},
				))),
				UnrewardedRelayersState {
					unrewarded_relayer_entries: 1,
					messages_in_oldest_entry: 1,
					total_messages: 1,
					last_delivered_nonce: 1,
				},
			));
		});
	}

	#[test]
	fn send_message_works() {
		run_test(|| {
			send_regular_message();
		});
	}

	#[test]
	fn send_message_rejects_too_large_message() {
		run_test(|| {
			let mut message_payload = message_payload(1, 0);
			// the payload isn't simply extra, so it'll definitely overflow
			// `MAX_OUTBOUND_PAYLOAD_SIZE` if we add `MAX_OUTBOUND_PAYLOAD_SIZE` bytes to extra
			message_payload
				.extra
				.extend_from_slice(&[0u8; MAX_OUTBOUND_PAYLOAD_SIZE as usize]);
			assert_noop!(
				send_message::<TestRuntime, ()>(
					RuntimeOrigin::signed(1),
					TEST_LANE_ID,
					message_payload.clone(),
				),
				Error::<TestRuntime, ()>::MessageIsTooLarge,
			);

			// let's check that we're able to send `MAX_OUTBOUND_PAYLOAD_SIZE` messages
			while message_payload.encoded_size() as u32 > MAX_OUTBOUND_PAYLOAD_SIZE {
				message_payload.extra.pop();
			}
			assert_eq!(message_payload.encoded_size() as u32, MAX_OUTBOUND_PAYLOAD_SIZE);
			assert_ok!(send_message::<TestRuntime, ()>(
				RuntimeOrigin::signed(1),
				TEST_LANE_ID,
				message_payload,
			),);
		})
	}

	#[test]
	fn chain_verifier_rejects_invalid_message_in_send_message() {
		run_test(|| {
			// messages with this payload are rejected by target chain verifier
			assert_noop!(
				send_message::<TestRuntime, ()>(
					RuntimeOrigin::signed(1),
					TEST_LANE_ID,
					PAYLOAD_REJECTED_BY_TARGET_CHAIN,
				),
				Error::<TestRuntime, ()>::MessageRejectedByChainVerifier,
			);
		});
	}

	#[test]
	fn lane_verifier_rejects_invalid_message_in_send_message() {
		run_test(|| {
			// messages with zero fee are rejected by lane verifier
			let mut message = REGULAR_PAYLOAD;
			message.reject_by_lane_verifier = true;
			assert_noop!(
				send_message::<TestRuntime, ()>(RuntimeOrigin::signed(1), TEST_LANE_ID, message,),
				Error::<TestRuntime, ()>::MessageRejectedByLaneVerifier,
			);
		});
	}

	#[test]
	fn receive_messages_proof_works() {
		run_test(|| {
			assert_ok!(Pallet::<TestRuntime>::receive_messages_proof(
				RuntimeOrigin::signed(1),
				TEST_RELAYER_A,
				Ok(vec![message(1, REGULAR_PAYLOAD)]).into(),
				1,
				REGULAR_PAYLOAD.declared_weight,
			));

			assert_eq!(InboundLanes::<TestRuntime>::get(TEST_LANE_ID).0.last_delivered_nonce(), 1);
		});
	}

	#[test]
	fn receive_messages_proof_updates_confirmed_message_nonce() {
		run_test(|| {
			// say we have received 10 messages && last confirmed message is 8
			InboundLanes::<TestRuntime, ()>::insert(
				TEST_LANE_ID,
				InboundLaneData {
					last_confirmed_nonce: 8,
					relayers: vec![
						unrewarded_relayer(9, 9, TEST_RELAYER_A),
						unrewarded_relayer(10, 10, TEST_RELAYER_B),
					]
					.into_iter()
					.collect(),
				},
			);
			assert_eq!(
				inbound_unrewarded_relayers_state(TEST_LANE_ID),
				UnrewardedRelayersState {
					unrewarded_relayer_entries: 2,
					messages_in_oldest_entry: 1,
					total_messages: 2,
					last_delivered_nonce: 10,
				},
			);

			// message proof includes outbound lane state with latest confirmed message updated to 9
			let mut message_proof: TestMessagesProof =
				Ok(vec![message(11, REGULAR_PAYLOAD)]).into();
			message_proof.result.as_mut().unwrap()[0].1.lane_state =
				Some(OutboundLaneData { latest_received_nonce: 9, ..Default::default() });

			assert_ok!(Pallet::<TestRuntime>::receive_messages_proof(
				RuntimeOrigin::signed(1),
				TEST_RELAYER_A,
				message_proof,
				1,
				REGULAR_PAYLOAD.declared_weight,
			));

			assert_eq!(
				InboundLanes::<TestRuntime>::get(TEST_LANE_ID).0,
				InboundLaneData {
					last_confirmed_nonce: 9,
					relayers: vec![
						unrewarded_relayer(10, 10, TEST_RELAYER_B),
						unrewarded_relayer(11, 11, TEST_RELAYER_A)
					]
					.into_iter()
					.collect(),
				},
			);
			assert_eq!(
				inbound_unrewarded_relayers_state(TEST_LANE_ID),
				UnrewardedRelayersState {
					unrewarded_relayer_entries: 2,
					messages_in_oldest_entry: 1,
					total_messages: 2,
					last_delivered_nonce: 11,
				},
			);
		});
	}

	#[test]
	fn receive_messages_proof_does_not_accept_message_if_dispatch_weight_is_not_enough() {
		run_test(|| {
			let mut declared_weight = REGULAR_PAYLOAD.declared_weight;
			*declared_weight.ref_time_mut() -= 1;
			assert_ok!(Pallet::<TestRuntime>::receive_messages_proof(
				RuntimeOrigin::signed(1),
				TEST_RELAYER_A,
				Ok(vec![message(1, REGULAR_PAYLOAD)]).into(),
				1,
				declared_weight,
			));
			assert_eq!(InboundLanes::<TestRuntime>::get(TEST_LANE_ID).last_delivered_nonce(), 0);
		});
	}

	#[test]
	fn receive_messages_proof_rejects_invalid_proof() {
		run_test(|| {
			assert_noop!(
				Pallet::<TestRuntime, ()>::receive_messages_proof(
					RuntimeOrigin::signed(1),
					TEST_RELAYER_A,
					Err(()).into(),
					1,
					Weight::from_ref_time(0),
				),
				Error::<TestRuntime, ()>::InvalidMessagesProof,
			);
		});
	}

	#[test]
	fn receive_messages_proof_rejects_proof_with_too_many_messages() {
		run_test(|| {
			assert_noop!(
				Pallet::<TestRuntime, ()>::receive_messages_proof(
					RuntimeOrigin::signed(1),
					TEST_RELAYER_A,
					Ok(vec![message(1, REGULAR_PAYLOAD)]).into(),
					u32::MAX,
					Weight::from_ref_time(0),
				),
				Error::<TestRuntime, ()>::TooManyMessagesInTheProof,
			);
		});
	}

	#[test]
	fn receive_messages_delivery_proof_works() {
		run_test(|| {
			send_regular_message();
			receive_messages_delivery_proof();

			assert_eq!(
				OutboundLanes::<TestRuntime, ()>::get(TEST_LANE_ID).latest_received_nonce,
				1,
			);
		});
	}

	#[test]
	fn receive_messages_delivery_proof_rewards_relayers() {
		run_test(|| {
			assert_ok!(send_message::<TestRuntime, ()>(
				RuntimeOrigin::signed(1),
				TEST_LANE_ID,
				REGULAR_PAYLOAD,
			));
			assert_ok!(send_message::<TestRuntime, ()>(
				RuntimeOrigin::signed(1),
				TEST_LANE_ID,
				REGULAR_PAYLOAD,
			));

			// this reports delivery of message 1 => reward is paid to TEST_RELAYER_A
			assert_ok!(Pallet::<TestRuntime>::receive_messages_delivery_proof(
				RuntimeOrigin::signed(1),
				TestMessagesDeliveryProof(Ok((
					TEST_LANE_ID,
					InboundLaneData {
						relayers: vec![unrewarded_relayer(1, 1, TEST_RELAYER_A)]
							.into_iter()
							.collect(),
						..Default::default()
					}
				))),
				UnrewardedRelayersState {
					unrewarded_relayer_entries: 1,
					total_messages: 1,
					last_delivered_nonce: 1,
					..Default::default()
				},
			));
			assert!(TestMessageDeliveryAndDispatchPayment::is_reward_paid(TEST_RELAYER_A, 1));
			assert!(!TestMessageDeliveryAndDispatchPayment::is_reward_paid(TEST_RELAYER_B, 1));

			// this reports delivery of both message 1 and message 2 => reward is paid only to
			// TEST_RELAYER_B
			assert_ok!(Pallet::<TestRuntime>::receive_messages_delivery_proof(
				RuntimeOrigin::signed(1),
				TestMessagesDeliveryProof(Ok((
					TEST_LANE_ID,
					InboundLaneData {
						relayers: vec![
							unrewarded_relayer(1, 1, TEST_RELAYER_A),
							unrewarded_relayer(2, 2, TEST_RELAYER_B)
						]
						.into_iter()
						.collect(),
						..Default::default()
					}
				))),
				UnrewardedRelayersState {
					unrewarded_relayer_entries: 2,
					total_messages: 2,
					last_delivered_nonce: 2,
					..Default::default()
				},
			));
			assert!(!TestMessageDeliveryAndDispatchPayment::is_reward_paid(TEST_RELAYER_A, 1));
			assert!(TestMessageDeliveryAndDispatchPayment::is_reward_paid(TEST_RELAYER_B, 1));
		});
	}

	#[test]
	fn receive_messages_delivery_proof_rejects_invalid_proof() {
		run_test(|| {
			assert_noop!(
				Pallet::<TestRuntime>::receive_messages_delivery_proof(
					RuntimeOrigin::signed(1),
					TestMessagesDeliveryProof(Err(())),
					Default::default(),
				),
				Error::<TestRuntime, ()>::InvalidMessagesDeliveryProof,
			);
		});
	}

	#[test]
	fn receive_messages_delivery_proof_rejects_proof_if_declared_relayers_state_is_invalid() {
		run_test(|| {
			// when number of relayers entries is invalid
			assert_noop!(
				Pallet::<TestRuntime>::receive_messages_delivery_proof(
					RuntimeOrigin::signed(1),
					TestMessagesDeliveryProof(Ok((
						TEST_LANE_ID,
						InboundLaneData {
							relayers: vec![
								unrewarded_relayer(1, 1, TEST_RELAYER_A),
								unrewarded_relayer(2, 2, TEST_RELAYER_B)
							]
							.into_iter()
							.collect(),
							..Default::default()
						}
					))),
					UnrewardedRelayersState {
						unrewarded_relayer_entries: 1,
						total_messages: 2,
						last_delivered_nonce: 2,
						..Default::default()
					},
				),
				Error::<TestRuntime, ()>::InvalidUnrewardedRelayersState,
			);

			// when number of messages is invalid
			assert_noop!(
				Pallet::<TestRuntime>::receive_messages_delivery_proof(
					RuntimeOrigin::signed(1),
					TestMessagesDeliveryProof(Ok((
						TEST_LANE_ID,
						InboundLaneData {
							relayers: vec![
								unrewarded_relayer(1, 1, TEST_RELAYER_A),
								unrewarded_relayer(2, 2, TEST_RELAYER_B)
							]
							.into_iter()
							.collect(),
							..Default::default()
						}
					))),
					UnrewardedRelayersState {
						unrewarded_relayer_entries: 2,
						total_messages: 1,
						last_delivered_nonce: 2,
						..Default::default()
					},
				),
				Error::<TestRuntime, ()>::InvalidUnrewardedRelayersState,
			);

			// when last delivered nonce is invalid
			assert_noop!(
				Pallet::<TestRuntime>::receive_messages_delivery_proof(
					RuntimeOrigin::signed(1),
					TestMessagesDeliveryProof(Ok((
						TEST_LANE_ID,
						InboundLaneData {
							relayers: vec![
								unrewarded_relayer(1, 1, TEST_RELAYER_A),
								unrewarded_relayer(2, 2, TEST_RELAYER_B)
							]
							.into_iter()
							.collect(),
							..Default::default()
						}
					))),
					UnrewardedRelayersState {
						unrewarded_relayer_entries: 2,
						total_messages: 2,
						last_delivered_nonce: 8,
						..Default::default()
					},
				),
				Error::<TestRuntime, ()>::InvalidUnrewardedRelayersState,
			);
		});
	}

	#[test]
	fn receive_messages_accepts_single_message_with_invalid_payload() {
		run_test(|| {
			let mut invalid_message = message(1, REGULAR_PAYLOAD);
			invalid_message.payload = Vec::new();

			assert_ok!(Pallet::<TestRuntime, ()>::receive_messages_proof(
				RuntimeOrigin::signed(1),
				TEST_RELAYER_A,
				Ok(vec![invalid_message]).into(),
				1,
				Weight::from_ref_time(0), /* weight may be zero in this case (all messages are
				                           * improperly encoded) */
			),);

			assert_eq!(InboundLanes::<TestRuntime>::get(TEST_LANE_ID).last_delivered_nonce(), 1,);
		});
	}

	#[test]
	fn receive_messages_accepts_batch_with_message_with_invalid_payload() {
		run_test(|| {
			let mut invalid_message = message(2, REGULAR_PAYLOAD);
			invalid_message.payload = Vec::new();

			assert_ok!(Pallet::<TestRuntime, ()>::receive_messages_proof(
				RuntimeOrigin::signed(1),
				TEST_RELAYER_A,
				Ok(
					vec![message(1, REGULAR_PAYLOAD), invalid_message, message(3, REGULAR_PAYLOAD),]
				)
				.into(),
				3,
				REGULAR_PAYLOAD.declared_weight + REGULAR_PAYLOAD.declared_weight,
			),);

			assert_eq!(InboundLanes::<TestRuntime>::get(TEST_LANE_ID).last_delivered_nonce(), 3,);
		});
	}

	#[test]
	fn actual_dispatch_weight_does_not_overlow() {
		run_test(|| {
			let message1 = message(1, message_payload(0, u64::MAX / 2));
			let message2 = message(2, message_payload(0, u64::MAX / 2));
			let message3 = message(3, message_payload(0, u64::MAX / 2));

			assert_ok!(Pallet::<TestRuntime, ()>::receive_messages_proof(
				RuntimeOrigin::signed(1),
				TEST_RELAYER_A,
				// this may cause overflow if source chain storage is invalid
				Ok(vec![message1, message2, message3]).into(),
				3,
				Weight::MAX,
			));
			assert_eq!(InboundLanes::<TestRuntime>::get(TEST_LANE_ID).last_delivered_nonce(), 2);
		});
	}

	#[test]
	fn weight_refund_from_receive_messages_proof_works() {
		run_test(|| {
			fn submit_with_unspent_weight(
				nonce: MessageNonce,
				unspent_weight: u64,
				is_prepaid: bool,
			) -> (Weight, Weight) {
				let mut payload = REGULAR_PAYLOAD;
				*payload.dispatch_result.unspent_weight.ref_time_mut() = unspent_weight;
				payload.dispatch_result.dispatch_fee_paid_during_dispatch = !is_prepaid;
				let proof = Ok(vec![message(nonce, payload)]).into();
				let messages_count = 1;
				let pre_dispatch_weight =
					<TestRuntime as Config>::WeightInfo::receive_messages_proof_weight(
						&proof,
						messages_count,
						REGULAR_PAYLOAD.declared_weight,
					);
				let post_dispatch_weight = Pallet::<TestRuntime>::receive_messages_proof(
					RuntimeOrigin::signed(1),
					TEST_RELAYER_A,
					proof,
					messages_count,
					REGULAR_PAYLOAD.declared_weight,
				)
				.expect("delivery has failed")
				.actual_weight
				.expect("receive_messages_proof always returns Some");

				(pre_dispatch_weight, post_dispatch_weight)
			}

			// when dispatch is returning `unspent_weight < declared_weight`
			let (pre, post) = submit_with_unspent_weight(1, 1, false);
			assert_eq!(post.ref_time(), pre.ref_time() - 1);

			// when dispatch is returning `unspent_weight = declared_weight`
			let (pre, post) =
				submit_with_unspent_weight(2, REGULAR_PAYLOAD.declared_weight.ref_time(), false);
			assert_eq!(
				post.ref_time(),
				pre.ref_time() - REGULAR_PAYLOAD.declared_weight.ref_time()
			);

			// when dispatch is returning `unspent_weight > declared_weight`
			let (pre, post) = submit_with_unspent_weight(
				3,
				REGULAR_PAYLOAD.declared_weight.ref_time() + 1,
				false,
			);
			assert_eq!(
				post.ref_time(),
				pre.ref_time() - REGULAR_PAYLOAD.declared_weight.ref_time()
			);

			// when there's no unspent weight
			let (pre, post) = submit_with_unspent_weight(4, 0, false);
			assert_eq!(post, pre);

			// when dispatch is returning `unspent_weight < declared_weight` AND message is prepaid
			let (pre, post) = submit_with_unspent_weight(5, 1, true);
			assert_eq!(
				post.ref_time(),
				pre.ref_time() -
					1 - <TestRuntime as Config>::WeightInfo::pay_inbound_dispatch_fee_overhead()
					.ref_time()
			);
		});
	}

	#[test]
	fn messages_delivered_callbacks_are_called() {
		run_test(|| {
			send_regular_message();
			send_regular_message();
			send_regular_message();

			// messages 1+2 are confirmed in 1 tx, message 3 in a separate tx
			// dispatch of message 2 has failed
			let mut delivered_messages_1_and_2 = DeliveredMessages::new(1, true);
			delivered_messages_1_and_2.note_dispatched_message(false);
			let messages_1_and_2_proof = Ok((
				TEST_LANE_ID,
				InboundLaneData {
					last_confirmed_nonce: 0,
					relayers: vec![UnrewardedRelayer {
						relayer: 0,
						messages: delivered_messages_1_and_2.clone(),
					}]
					.into_iter()
					.collect(),
				},
			));
			let delivered_message_3 = DeliveredMessages::new(3, true);
			let messages_3_proof = Ok((
				TEST_LANE_ID,
				InboundLaneData {
					last_confirmed_nonce: 0,
					relayers: vec![UnrewardedRelayer {
						relayer: 0,
						messages: delivered_message_3.clone(),
					}]
					.into_iter()
					.collect(),
				},
			));

			// first tx with messages 1+2
			assert_ok!(Pallet::<TestRuntime>::receive_messages_delivery_proof(
				RuntimeOrigin::signed(1),
				TestMessagesDeliveryProof(messages_1_and_2_proof),
				UnrewardedRelayersState {
					unrewarded_relayer_entries: 1,
					total_messages: 2,
					last_delivered_nonce: 2,
					..Default::default()
				},
			));
			// second tx with message 3
			assert_ok!(Pallet::<TestRuntime>::receive_messages_delivery_proof(
				RuntimeOrigin::signed(1),
				TestMessagesDeliveryProof(messages_3_proof),
				UnrewardedRelayersState {
					unrewarded_relayer_entries: 1,
					total_messages: 1,
					last_delivered_nonce: 3,
					..Default::default()
				},
			));

			// ensure that both callbacks have been called twice: for 1+2, then for 3
			TestOnDeliveryConfirmed1::ensure_called(&TEST_LANE_ID, &delivered_messages_1_and_2);
			TestOnDeliveryConfirmed1::ensure_called(&TEST_LANE_ID, &delivered_message_3);
			TestOnDeliveryConfirmed2::ensure_called(&TEST_LANE_ID, &delivered_messages_1_and_2);
			TestOnDeliveryConfirmed2::ensure_called(&TEST_LANE_ID, &delivered_message_3);
		});
	}

	fn confirm_3_messages_delivery() -> (Weight, Weight) {
		send_regular_message();
		send_regular_message();
		send_regular_message();

		let proof = TestMessagesDeliveryProof(Ok((
			TEST_LANE_ID,
			InboundLaneData {
				last_confirmed_nonce: 0,
				relayers: vec![unrewarded_relayer(1, 3, TEST_RELAYER_A)].into_iter().collect(),
			},
		)));
		let relayers_state = UnrewardedRelayersState {
			unrewarded_relayer_entries: 1,
			total_messages: 3,
			last_delivered_nonce: 3,
			..Default::default()
		};
		let pre_dispatch_weight =
			<TestRuntime as Config>::WeightInfo::receive_messages_delivery_proof_weight(
				&proof,
				&relayers_state,
				crate::mock::DbWeight::get(),
			);
		let post_dispatch_weight = Pallet::<TestRuntime>::receive_messages_delivery_proof(
			RuntimeOrigin::signed(1),
			proof,
			relayers_state,
		)
		.expect("confirmation has failed")
		.actual_weight
		.expect("receive_messages_delivery_proof always returns Some");
		(pre_dispatch_weight, post_dispatch_weight)
	}

	#[test]
	fn receive_messages_delivery_proof_refunds_zero_weight() {
		run_test(|| {
			let (pre_dispatch_weight, post_dispatch_weight) = confirm_3_messages_delivery();
			assert_eq!(pre_dispatch_weight, post_dispatch_weight);
		});
	}

	#[test]
	fn receive_messages_delivery_proof_refunds_non_zero_weight() {
		run_test(|| {
			TestOnDeliveryConfirmed1::set_consumed_weight_per_message(
				crate::mock::DbWeight::get().writes(1),
			);

			let (pre_dispatch_weight, post_dispatch_weight) = confirm_3_messages_delivery();
			assert_eq!(
				pre_dispatch_weight.saturating_sub(post_dispatch_weight),
				crate::mock::DbWeight::get().reads(1) * 3
			);
		});
	}

	#[test]
	#[should_panic]
	#[cfg(debug_assertions)]
	fn receive_messages_panics_in_debug_mode_if_callback_is_wrong() {
		run_test(|| {
			TestOnDeliveryConfirmed1::set_consumed_weight_per_message(
				crate::mock::DbWeight::get().reads_writes(2, 2),
			);
			confirm_3_messages_delivery()
		});
	}

	#[test]
	fn receive_messages_delivery_proof_rejects_proof_if_trying_to_confirm_more_messages_than_expected(
	) {
		run_test(|| {
			// send message first to be able to check that delivery_proof fails later
			send_regular_message();

			// 1) InboundLaneData declares that the `last_confirmed_nonce` is 1;
			// 2) InboundLaneData has no entries => `InboundLaneData::last_delivered_nonce()`
			//    returns `last_confirmed_nonce`;
			// 3) it means that we're going to confirm delivery of messages 1..=1;
			// 4) so the number of declared messages (see `UnrewardedRelayersState`) is `0` and
			//    numer of actually confirmed messages is `1`.
			assert_noop!(
				Pallet::<TestRuntime>::receive_messages_delivery_proof(
					RuntimeOrigin::signed(1),
					TestMessagesDeliveryProof(Ok((
						TEST_LANE_ID,
						InboundLaneData { last_confirmed_nonce: 1, relayers: Default::default() },
					))),
					UnrewardedRelayersState { last_delivered_nonce: 1, ..Default::default() },
				),
				Error::<TestRuntime, ()>::TryingToConfirmMoreMessagesThanExpected,
			);
		});
	}

	#[test]
	fn message_accepted_callbacks_are_called() {
		run_test(|| {
			send_regular_message();
			TestOnMessageAccepted::ensure_called(&TEST_LANE_ID, &1);
		});
	}

	#[test]
	#[should_panic]
	#[cfg(debug_assertions)]
	fn message_accepted_panics_in_debug_mode_if_callback_is_wrong() {
		run_test(|| {
			TestOnMessageAccepted::set_consumed_weight_per_message(
				crate::mock::DbWeight::get().reads_writes(2, 2),
			);
			send_regular_message();
		});
	}

	#[test]
	fn storage_keys_computed_properly() {
		assert_eq!(
			PalletOperatingMode::<TestRuntime>::storage_value_final_key().to_vec(),
			bp_messages::storage_keys::operating_mode_key("Messages").0,
		);

		assert_eq!(
			OutboundMessages::<TestRuntime>::storage_map_final_key(MessageKey {
				lane_id: TEST_LANE_ID,
				nonce: 42
			}),
			bp_messages::storage_keys::message_key("Messages", &TEST_LANE_ID, 42).0,
		);

		assert_eq!(
			OutboundLanes::<TestRuntime>::storage_map_final_key(TEST_LANE_ID),
			bp_messages::storage_keys::outbound_lane_data_key("Messages", &TEST_LANE_ID).0,
		);

		assert_eq!(
			InboundLanes::<TestRuntime>::storage_map_final_key(TEST_LANE_ID),
			bp_messages::storage_keys::inbound_lane_data_key("Messages", &TEST_LANE_ID).0,
		);
	}

	#[test]
	fn inbound_message_details_works() {
		run_test(|| {
			assert_eq!(
				Pallet::<TestRuntime>::inbound_message_data(
					TEST_LANE_ID,
					REGULAR_PAYLOAD.encode(),
					OutboundMessageDetails {
						nonce: 0,
						dispatch_weight: Weight::from_ref_time(0),
						size: 0,
					},
				),
				InboundMessageDetails { dispatch_weight: REGULAR_PAYLOAD.declared_weight },
			);
		});
	}

	generate_owned_bridge_module_tests!(
		MessagesOperatingMode::Basic(BasicOperatingMode::Normal),
		MessagesOperatingMode::Basic(BasicOperatingMode::Halted)
	);
}