Test host functions

node/Cargo.toml

@@ -36,6 +36,7 @@ tokio = { version = "0.2.13", features = ["macros", "sync"] }
 moonbeam-runtime = { path = "../runtime" }
 moonbeam-rpc-txpool = { path = "../client/rpc/txpool" }
 moonbeam-rpc-primitives-txpool = { path = "../primitives/rpc/txpool" }
+moonbeam-primitives-ext = { path = "../primitives/ext" }
 moonbeam-rpc-debug = { path = "../client/rpc/debug" }
 moonbeam-rpc-primitives-debug = { path = "../primitives/rpc/debug" }
 moonbeam-rpc-trace = { path = "../client/rpc/trace" }

node/src/service.rs

@@ -65,7 +65,8 @@ native_executor_instance!(
 	pub Executor,
 	moonbeam_runtime::api::dispatch,
 	moonbeam_runtime::native_version,
-	frame_benchmarking::benchmarking::HostFunctions,
+	// Make the executor aware of the custom host functions.
+	(frame_benchmarking::benchmarking::HostFunctions, moonbeam_primitives_ext::moonbeam_ext::HostFunctions),
 );
 use sc_telemetry::{Telemetry, TelemetryWorker, TelemetryWorkerHandle};
 

primitives/ext/Cargo.toml

@@ -0,0 +1,19 @@
+[package]
+name = "moonbeam-primitives-ext"
+version = '0.1.0'
+authors = ['PureStake']
+edition = '2018'
+homepage = 'https://moonbeam.network'
+license = 'GPL-3.0-only'
+repository = 'https://github.com/PureStake/moonbeam/'
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+sp-runtime-interface = { git = "https://github.com/paritytech/substrate.git", branch = "rococo-v1",default-features = false }
+
+[features]
+default = ["std"]
+std = [
+	"sp-runtime-interface/std",
+]

primitives/ext/src/lib.rs

@@ -0,0 +1,10 @@
+#![cfg_attr(not(feature = "std"), no_std)]
+
+use sp_runtime_interface::runtime_interface;
+
+#[runtime_interface]
+pub trait MoonbeamExt {
+    fn foo() {
+        println!("Called from the runtime!");
+    }
+}

runtime/Cargo.toml

@@ -58,6 +58,7 @@ pallet-collective = { git = "https://github.com/paritytech/substrate", default-f
 moonbeam-extensions-evm = { path = "extensions/evm", default-features = false }
 moonbeam-rpc-primitives-debug = { path = "../primitives/rpc/debug", default-features = false }
 moonbeam-rpc-primitives-txpool = { path = "../primitives/rpc/txpool", default-features = false }
+moonbeam-primitives-ext = { path = "../primitives/ext", default-features = false  }
 
 # Cumulus dependencies
 cumulus-pallet-parachain-system = { git = "https://github.com/paritytech/cumulus", default-features = false, branch = "rococo-v1" }

runtime/src/lib.rs

@@ -918,6 +918,8 @@ impl_runtime_apis! {
 
 	impl fp_rpc::EthereumRuntimeRPCApi<Block> for Runtime {
 		fn chain_id() -> u64 {
+			// Just find some place in the runtime to call it.
+			moonbeam_primitives_ext::moonbeam_ext::foo();
 			<Runtime as pallet_evm::Config>::ChainId::get()
 		}