parachains relay now only works with single parachain

relays/client-substrate/src/test_chain.rs

@@ -66,3 +66,51 @@ impl ChainWithBalances for TestChain {
 		unreachable!()
 	}
 }
+
+/// Primitives-level parachain that may be used in tests.
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub struct TestParachainBase;
+
+impl bp_runtime::Chain for TestParachainBase {
+	type BlockNumber = u32;
+	type Hash = sp_core::H256;
+	type Hasher = sp_runtime::traits::BlakeTwo256;
+	type Header = sp_runtime::generic::Header<u32, sp_runtime::traits::BlakeTwo256>;
+
+	type AccountId = u32;
+	type Balance = u32;
+	type Index = u32;
+	type Signature = sp_runtime::testing::TestSignature;
+
+	fn max_extrinsic_size() -> u32 {
+		unreachable!()
+	}
+
+	fn max_extrinsic_weight() -> Weight {
+		unreachable!()
+	}
+}
+
+impl bp_runtime::Parachain for TestParachainBase {
+	const PARACHAIN_ID: u32 = 1000;
+}
+
+/// Parachain that may be used in tests.
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub struct TestParachain;
+
+impl bp_runtime::UnderlyingChainProvider for TestParachain {
+	type Chain = TestParachainBase;
+}
+
+impl Chain for TestParachain {
+	const NAME: &'static str = "TestParachain";
+	const TOKEN_ID: Option<&'static str> = None;
+	const BEST_FINALIZED_HEADER_ID_METHOD: &'static str = "TestParachainMethod";
+	const AVERAGE_BLOCK_INTERVAL: Duration = Duration::from_millis(0);
+
+	type SignedBlock = sp_runtime::generic::SignedBlock<
+		sp_runtime::generic::Block<Self::Header, sp_runtime::OpaqueExtrinsic>,
+	>;
+	type Call = ();
+}

relays/parachains/Cargo.toml

@@ -14,7 +14,6 @@ relay-utils = { path = "../utils" }
 
 # Bridge dependencies
 
-bp-parachains = { path = "../../primitives/parachains" }
 bp-polkadot-core = { path = "../../primitives/polkadot-core" }
 relay-substrate-client = { path = "../client-substrate" }
 

relays/parachains/src/lib.rs

@@ -16,15 +16,17 @@
 
 use std::fmt::Debug;
 
-use relay_substrate_client::Chain;
+use relay_substrate_client::{Chain, Parachain};
 
 pub mod parachains_loop;
 pub mod parachains_loop_metrics;
 
 /// Finality proofs synchronization pipeline.
 pub trait ParachainsPipeline: 'static + Clone + Debug + Send + Sync {
 	/// Relay chain which is storing parachain heads in its `paras` module.
-	type SourceChain: Chain;
+	type SourceRelayChain: Chain;
+	/// Parachain which headers we are syncing here.
+	type SourceParachain: Parachain;
 	/// Target chain (either relay or para) which wants to know about new parachain heads.
 	type TargetChain: Chain;
 }