add test

pallets/parachain-system/src/tests.rs

@@ -687,6 +687,60 @@ fn inherent_processed_messages_are_ignored() {
 		});
 }
 
+#[test]
+fn hrmp_outbound_respects_used_bandwidth() {
+	let recipient = ParaId::from(400);
+
+	CONSENSUS_HOOK.with(|c| {
+		*c.borrow_mut() = Box::new(|_| (Weight::zero(), NonZeroU32::new(3).unwrap().into()))
+	});
+
+	BlockTests::new()
+		.with_inclusion_delay(2)
+		.with_relay_sproof_builder(move |_, _, sproof| {
+			sproof.host_config.hrmp_max_message_num_per_candidate = 10;
+			let channel = sproof.upsert_outbound_channel(recipient);
+			channel.max_capacity = 2;
+			channel.max_total_size = 4;
+
+			channel.max_message_size = 10;
+		})
+		.add(1, || {})
+		.add_with_post_test(
+			2,
+			move || {
+				send_message(recipient, b"22".to_vec());
+			},
+			move || {
+				let v = HrmpOutboundMessages::<Test>::get();
+				assert_eq!(v, vec![OutboundHrmpMessage { recipient, data: b"22".to_vec() }]);
+			},
+		)
+		.add_with_post_test(
+			3,
+			move || {
+				send_message(recipient, b"333".to_vec());
+			},
+			move || {
+				// Parent has not been included, new message would've exceeded capacity.
+				let v = HrmpOutboundMessages::<Test>::get();
+				assert!(v.is_empty());
+			},
+		)
+		.add_with_post_test(
+			4,
+			move || {
+				send_message(recipient, b"a".to_vec());
+				send_message(recipient, b"b".to_vec());
+			},
+			move || {
+				let v = HrmpOutboundMessages::<Test>::get();
+				// One small message fits. This line relies on test implementation of [`XcmpMessageSource`].
+				assert_eq!(v, vec![OutboundHrmpMessage { recipient, data: b"a".to_vec() }]);
+			},
+		);
+}
+
 #[test]
 fn events() {
 	BlockTests::new()

test/relay-sproof-builder/src/lib.rs

@@ -91,16 +91,34 @@ impl RelayStateSproofBuilder {
 			in_index.insert(idx, sender);
 		}
 
-		self.hrmp_channels
-			.entry(relay_chain::HrmpChannelId { sender, recipient: self.para_id })
-			.or_insert_with(|| AbridgedHrmpChannel {
-				max_capacity: 0,
-				max_total_size: 0,
-				max_message_size: 0,
-				msg_count: 0,
-				total_size: 0,
-				mqc_head: None,
-			})
+		self.upsert_channel(relay_chain::HrmpChannelId { sender, recipient: self.para_id })
+	}
+
+	/// Returns a mutable reference to HRMP channel metadata for a channel (`self.para_id`, `recipient`).
+	///
+	/// If there is no channel, a new default one is created.
+	///
+	/// It also updates the `hrmp_egress_channel_index`, creating it if needed.
+	pub fn upsert_outbound_channel(&mut self, recipient: ParaId) -> &mut AbridgedHrmpChannel {
+		let in_index = self.hrmp_egress_channel_index.get_or_insert_with(Vec::new);
+		if let Err(idx) = in_index.binary_search(&recipient) {
+			in_index.insert(idx, recipient);
+		}
+
+		self.upsert_channel(relay_chain::HrmpChannelId { sender: self.para_id, recipient })
+	}
+
+	/// Creates a new default entry in the hrmp channels mapping if not exists, and returns mutable
+	/// reference to it.
+	fn upsert_channel(&mut self, id: relay_chain::HrmpChannelId) -> &mut AbridgedHrmpChannel {
+		self.hrmp_channels.entry(id).or_insert_with(|| AbridgedHrmpChannel {
+			max_capacity: 0,
+			max_total_size: 0,
+			max_message_size: 0,
+			msg_count: 0,
+			total_size: 0,
+			mqc_head: None,
+		})
 	}
 
 	pub fn into_state_root_and_proof(