Runtime benchmarks: start (#136)

* runtime benchmarks: start

* merge tests + benchmarks infrastructure

* fix compilation

* Fix compilation issues with runtime-benchmark feature flag

Mainly involved pulling in correct dependencies and adding some functions
which were called but didn't yet exist.

* Fix broken compilation for tests

* Move header signing methods into trait

* Move signing related test helpers to own module

* Remove comment about feature flag

* Add constants to tests

* Add top level comment for testing utilities

Co-authored-by: Hernando Castano <castano.ha@gmail.com>

bridges/bin/node/node/Cargo.toml

@@ -115,6 +115,16 @@ version = "2.0.0-rc3"
 rev = "606c56d2e2f69f68f3947551224be6a3515dff60"
 git = "https://github.com/paritytech/substrate.git"
 
+[dependencies.frame-benchmarking]
+version = "2.0.0-rc3"
+rev = "606c56d2e2f69f68f3947551224be6a3515dff60"
+git = "https://github.com/paritytech/substrate.git"
+
+[dependencies.frame-benchmarking-cli]
+version = "2.0.0-rc3"
+rev = "606c56d2e2f69f68f3947551224be6a3515dff60"
+git = "https://github.com/paritytech/substrate.git"
+
 [build-dependencies]
 vergen = "3.1.0"
 
@@ -123,3 +133,14 @@ package = "substrate-build-script-utils"
 version = "2.0.0-rc3"
 rev = "606c56d2e2f69f68f3947551224be6a3515dff60"
 git = "https://github.com/paritytech/substrate.git"
+
+[build-dependencies.frame-benchmarking-cli]
+version = "2.0.0-rc3"
+rev = "606c56d2e2f69f68f3947551224be6a3515dff60"
+git = "https://github.com/paritytech/substrate.git"
+
+[features]
+default = []
+runtime-benchmarks = [
+	"bridge-node-runtime/runtime-benchmarks",
+]

bridges/bin/node/node/src/cli.rs

@@ -14,7 +14,7 @@
 // You should have received a copy of the GNU General Public License
 // along with Parity Bridges Common.  If not, see <http://www.gnu.org/licenses/>.
 
-use sc_cli::{RunCmd, Subcommand};
+use sc_cli::RunCmd;
 use structopt::StructOpt;
 
 #[derive(Debug, StructOpt)]
@@ -25,3 +25,15 @@ pub struct Cli {
 	#[structopt(flatten)]
 	pub run: RunCmd,
 }
+
+/// Possible subcommands of the main binary.
+#[derive(Debug, StructOpt)]
+pub enum Subcommand {
+	/// A set of base subcommands handled by `sc_cli`.
+	#[structopt(flatten)]
+	Base(sc_cli::Subcommand),
+
+	/// The custom benchmark subcommmand benchmarking runtime pallets.
+	#[structopt(name = "benchmark", about = "Benchmark runtime pallets.")]
+	Benchmark(frame_benchmarking_cli::BenchmarkCmd),
+}

bridges/bin/node/node/src/command.rs

@@ -30,8 +30,9 @@
 // You should have received a copy of the GNU General Public License
 // along with Parity Bridges Common.  If not, see <http://www.gnu.org/licenses/>.
 
-use crate::cli::Cli;
+use crate::cli::{Cli, Subcommand};
 use crate::service;
+use bridge_node_runtime::Block;
 use sc_cli::SubstrateCli;
 use sp_consensus_aura::sr25519::AuthorityPair as AuraPair;
 
@@ -81,7 +82,20 @@ pub fn run() -> sc_cli::Result<()> {
 	let cli = Cli::from_args();
 
 	match &cli.subcommand {
-		Some(subcommand) => {
+		Some(Subcommand::Benchmark(cmd)) => {
+			if cfg!(feature = "runtime-benchmarks") {
+				let runner = cli.create_runner(cmd)?;
+
+				runner.sync_run(|config| cmd.run::<Block, service::Executor>(config))
+			} else {
+				println!(
+					"Benchmarking wasn't enabled when building the node. \
+				You can enable it with `--features runtime-benchmarks`."
+				);
+				Ok(())
+			}
+		}
+		Some(Subcommand::Base(subcommand)) => {
 			let runner = cli.create_runner(subcommand)?;
 			runner.run_subcommand(subcommand, |config| Ok(new_full_start!(config).0))
 		}

bridges/bin/node/node/src/service.rs

@@ -33,6 +33,7 @@ native_executor_instance!(
 	pub Executor,
 	bridge_node_runtime::api::dispatch,
 	bridge_node_runtime::native_version,
+	frame_benchmarking::benchmarking::HostFunctions,
 );
 
 /// Starts a `ServiceBuilder` for a full service.

bridges/bin/node/runtime/Cargo.toml

@@ -195,6 +195,13 @@ default-features = false
 rev = "606c56d2e2f69f68f3947551224be6a3515dff60"
 git = "https://github.com/paritytech/substrate/"
 
+[dependencies.frame-benchmarking]
+optional = true
+version = "2.0.0-rc3"
+default-features = false
+rev = "606c56d2e2f69f68f3947551224be6a3515dff60"
+git = "https://github.com/paritytech/substrate/"
+
 [build-dependencies.wasm-builder-runner]
 version = "1.0.5"
 package = "substrate-wasm-builder-runner"
@@ -209,6 +216,7 @@ std = [
 	"pallet-bridge-eth-poa/std",
 	"pallet-bridge-currency-exchange/std",
 	"codec/std",
+	"frame-benchmarking/std",
 	"frame-executive/std",
 	"frame-support/std",
 	"frame-system/std",
@@ -234,3 +242,11 @@ std = [
 	"pallet-timestamp/std",
 	"pallet-transaction-payment/std",
 ]
+runtime-benchmarks = [
+	"frame-benchmarking",
+	"frame-support/runtime-benchmarks",
+	"frame-system/runtime-benchmarks",
+	"pallet-bridge-currency-exchange/runtime-benchmarks",
+	"pallet-bridge-eth-poa/runtime-benchmarks",
+	"sp-runtime/runtime-benchmarks",
+]

bridges/bin/node/runtime/build.rs

@@ -19,7 +19,7 @@ use wasm_builder_runner::WasmBuilder;
 fn main() {
 	WasmBuilder::new()
 		.with_current_project()
-		.with_wasm_builder_from_crates("1.0.9")
+		.with_wasm_builder_from_crates("1.0.11")
 		.export_heap_base()
 		.import_memory()
 		.build()

bridges/bin/node/runtime/src/lib.rs

@@ -573,6 +573,27 @@ impl_runtime_apis! {
 			None
 		}
 	}
+
+	#[cfg(feature = "runtime-benchmarks")]
+	impl frame_benchmarking::Benchmark<Block> for Runtime {
+		fn dispatch_benchmark(
+			pallet: Vec<u8>,
+			benchmark: Vec<u8>,
+			lowest_range_values: Vec<u32>,
+			highest_range_values: Vec<u32>,
+			steps: Vec<u32>,
+			repeat: u32,
+		) -> Result<Vec<frame_benchmarking::BenchmarkBatch>, sp_runtime::RuntimeString> {
+			use frame_benchmarking::{Benchmarking, BenchmarkBatch, add_benchmark};
+			let mut batches = Vec::<BenchmarkBatch>::new();
+			let params = (&pallet, &benchmark, &lowest_range_values, &highest_range_values, &steps, repeat);
+
+			add_benchmark!(params, batches, b"bridge-eth-poa", BridgeEthPoA);
+
+			if batches.is_empty() { return Err("Benchmark not found for this pallet.".into()) }
+			Ok(batches)
+		}
+	}
 }
 
 #[cfg(test)]

bridges/modules/currency-exchange/Cargo.toml

@@ -35,6 +35,13 @@ default-features = false
 rev = "606c56d2e2f69f68f3947551224be6a3515dff60"
 git = "https://github.com/paritytech/substrate/"
 
+[dependencies.frame-benchmarking]
+optional = true
+version = "2.0.0-rc3"
+default-features = false
+rev = "606c56d2e2f69f68f3947551224be6a3515dff60"
+git = "https://github.com/paritytech/substrate/"
+
 [dev-dependencies.sp-core]
 version = "2.0.0-rc3"
 rev = "606c56d2e2f69f68f3947551224be6a3515dff60"
@@ -48,11 +55,13 @@ git = "https://github.com/paritytech/substrate/"
 [features]
 default = ["std"]
 std = [
-	"serde",
 	"codec/std",
-	"sp-std/std",
+	"frame-benchmarking/std",
 	"frame-support/std",
 	"frame-system/std",
-	"sp-runtime/std",
+	"serde",
 	"sp-currency-exchange/std",
+	"sp-std/std",
+	"sp-runtime/std",
 ]
+runtime-benchmarks = ["frame-benchmarking"]

bridges/modules/ethereum/Cargo.toml

@@ -8,6 +8,7 @@ edition = "2018"
 [dependencies]
 serde = { version = "1.0", optional = true }
 codec = { package = "parity-scale-codec", version = "1.0.0", default-features = false }
+hex-literal = "0.2"
 primitives = { package = "sp-bridge-eth-poa", path = "../../primitives/ethereum-poa", default-features = false }
 
 # Substrate Based Dependencies
@@ -41,21 +42,40 @@ default-features = false
 rev = "606c56d2e2f69f68f3947551224be6a3515dff60"
 git = "https://github.com/paritytech/substrate/"
 
+[dependencies.frame-benchmarking]
+optional = true
+version = "2.0.0-rc3"
+default-features = false
+rev = "606c56d2e2f69f68f3947551224be6a3515dff60"
+git = "https://github.com/paritytech/substrate/"
+
+[dependencies.libsecp256k1]
+optional = true
+version = "0.3.4"
+default-features = false
+features = ["hmac"]
+
 # Dev Dependencies
 [dev-dependencies]
 # TODO: Stop renaming this on import
 primitives = { package = "sp-bridge-eth-poa", path = "../../primitives/ethereum-poa", features = ["std", "test-helpers"] }
-parity-crypto = { version = "0.6", features = ["publickey"] }
+libsecp256k1 = { version = "0.3.4", features = ["hmac"] }
 
 [features]
 default = ["std"]
 std = [
-	"serde",
 	"codec/std",
-	"sp-std/std",
+	"frame-benchmarking/std",
 	"frame-support/std",
-	"sp-runtime/std",
 	"frame-system/std",
-	"sp-io/std",
 	"primitives/std",
+	"serde",
+	"sp-io/std",
+	"sp-runtime/std",
+	"sp-std/std",
+]
+runtime-benchmarks = [
+	"frame-benchmarking",
+	"libsecp256k1",
+	"primitives/test-helpers",
 ]

bridges/modules/ethereum/src/benchmarking.rs

@@ -0,0 +1,60 @@
+// Copyright 2019-2020 Parity Technologies (UK) Ltd.
+// This file is part of Parity Bridges Common.
+
+// Parity Bridges Common is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Parity Bridges Common is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Parity Bridges Common.  If not, see <http://www.gnu.org/licenses/>.
+
+use super::*;
+
+use crate::test_utils::{build_custom_header, build_genesis_header, validator_utils::*};
+
+use frame_benchmarking::benchmarks;
+use frame_system::RawOrigin;
+use primitives::U256;
+
+benchmarks! {
+	_ { }
+
+	// Benchmark `import_unsigned_header` extrinsic with the best possible conditions:
+	// * Parent header is finalized.
+	// * New header doesn't require receipts.
+	// * Nothing is finalized by new header.
+	// * Nothing is pruned by new header.
+	import_unsigned_header_best_case {
+		let n in 1..1000;
+
+		// initialize storage with some initial header
+		let initial_header = build_genesis_header(&validator(0));
+		let initial_header_hash = initial_header.compute_hash();
+		let initial_difficulty = initial_header.difficulty;
+		initialize_storage::<T>(
+			&initial_header,
+			initial_difficulty,
+			&validators_addresses(2),
+		);
+
+		// prepare header to be inserted
+		let header = build_custom_header(
+			&validator(1),
+			&initial_header,
+			|mut header| {
+				header.gas_limit = header.gas_limit + U256::from(n);
+				header
+			},
+		);
+
+	}: import_unsigned_header(RawOrigin::None, header, None)
+	verify {
+		assert_eq!(BridgeStorage::<T>::new().best_block().0.number, 1);
+	}
+}

bridges/modules/ethereum/src/finality.rs

@@ -282,13 +282,15 @@ impl<Submitter> Default for FinalityVotes<Submitter> {
 #[cfg(test)]
 mod tests {
 	use super::*;
-	use crate::mock::{custom_test_ext, genesis, insert_header, validator, validators_addresses, TestRuntime};
+	use crate::mock::{insert_header, run_test, validator, validators_addresses, HeaderBuilder, TestRuntime};
 	use crate::{BridgeStorage, FinalityCache, HeaderToImport};
 	use frame_support::StorageMap;
 
+	const TOTAL_VALIDATORS: usize = 5;
+
 	#[test]
 	fn verifies_header_author() {
-		custom_test_ext(genesis(), validators_addresses(5)).execute_with(|| {
+		run_test(TOTAL_VALIDATORS, |_| {
 			assert_eq!(
 				finalize_blocks(
 					&BridgeStorage::<TestRuntime>::new(),
@@ -306,21 +308,16 @@ mod tests {
 
 	#[test]
 	fn finalize_blocks_works() {
-		custom_test_ext(genesis(), validators_addresses(5)).execute_with(|| {
+		run_test(TOTAL_VALIDATORS, |ctx| {
 			// let's say we have 5 validators (we need 'votes' from 3 validators to achieve
 			// finality)
 			let mut storage = BridgeStorage::<TestRuntime>::new();
 
 			// when header#1 is inserted, nothing is finalized (1 vote)
-			let header1 = Header {
-				author: validator(0).address().as_fixed_bytes().into(),
-				parent_hash: genesis().compute_hash(),
-				number: 1,
-				..Default::default()
-			};
+			let header1 = HeaderBuilder::with_parent(&ctx.genesis).sign_by(&validator(0));
 			let id1 = header1.compute_id();
 			let mut header_to_import = HeaderToImport {
-				context: storage.import_context(None, &genesis().compute_hash()).unwrap(),
+				context: storage.import_context(None, &header1.parent_hash).unwrap(),
 				is_best: true,
 				id: id1,
 				header: header1,
@@ -332,8 +329,8 @@ mod tests {
 			assert_eq!(
 				finalize_blocks(
 					&storage,
-					genesis().compute_id(),
-					(Default::default(), &validators_addresses(5)),
+					ctx.genesis.compute_id(),
+					(Default::default(), &ctx.addresses),
 					id1,
 					None,
 					&header_to_import.header,
@@ -345,19 +342,14 @@ mod tests {
 			storage.insert_header(header_to_import.clone());
 
 			// when header#2 is inserted, nothing is finalized (2 votes)
-			header_to_import.header = Header {
-				author: validator(1).address().as_fixed_bytes().into(),
-				parent_hash: id1.hash,
-				number: 2,
-				..Default::default()
-			};
+			header_to_import.header = HeaderBuilder::with_parent_hash(id1.hash).sign_by(&validator(1));
 			header_to_import.id = header_to_import.header.compute_id();
 			let id2 = header_to_import.header.compute_id();
 			assert_eq!(
 				finalize_blocks(
 					&storage,
-					genesis().compute_id(),
-					(Default::default(), &validators_addresses(5)),
+					ctx.genesis.compute_id(),
+					(Default::default(), &ctx.addresses),
 					id2,
 					None,
 					&header_to_import.header,
@@ -369,19 +361,14 @@ mod tests {
 			storage.insert_header(header_to_import.clone());
 
 			// when header#3 is inserted, header#1 is finalized (3 votes)
-			header_to_import.header = Header {
-				author: validator(2).address().as_fixed_bytes().into(),
-				parent_hash: id2.hash,
-				number: 3,
-				..Default::default()
-			};
+			header_to_import.header = HeaderBuilder::with_parent_hash(id2.hash).sign_by(&validator(2));
 			header_to_import.id = header_to_import.header.compute_id();
 			let id3 = header_to_import.header.compute_id();
 			assert_eq!(
 				finalize_blocks(
 					&storage,
-					genesis().compute_id(),
-					(Default::default(), &validators_addresses(5)),
+					ctx.genesis.compute_id(),
+					(Default::default(), &ctx.addresses),
 					id3,
 					None,
 					&header_to_import.header,
@@ -404,11 +391,7 @@ mod tests {
 		// 2) add votes from header#4 and header#5
 		let validators = validators_addresses(5);
 		let headers = (1..6)
-			.map(|number| Header {
-				number: number,
-				author: validators[number as usize - 1],
-				..Default::default()
-			})
+			.map(|number| HeaderBuilder::with_number(number).sign_by(&validator(number as usize - 1)))
 			.collect::<Vec<_>>();
 		let ancestry = headers
 			.iter()
@@ -451,8 +434,7 @@ mod tests {
 
 	#[test]
 	fn prepare_votes_respects_finality_cache() {
-		let validators_addresses = validators_addresses(5);
-		custom_test_ext(genesis(), validators_addresses.clone()).execute_with(move || {
+		run_test(TOTAL_VALIDATORS, |ctx| {
 			// we need signatures of 3 validators to finalize block
 			let mut storage = BridgeStorage::<TestRuntime>::new();
 
@@ -462,14 +444,9 @@ mod tests {
 			let mut hashes = Vec::new();
 			let mut headers = Vec::new();
 			let mut ancestry = Vec::new();
-			let mut parent_hash = genesis().compute_hash();
+			let mut parent_hash = ctx.genesis.compute_hash();
 			for i in 1..10 {
-				let header = Header {
-					author: validator((i - 1) / 3).address().as_fixed_bytes().into(),
-					parent_hash,
-					number: i as _,
-					..Default::default()
-				};
+				let header = HeaderBuilder::with_parent_hash(parent_hash).sign_by(&validator((i - 1) / 3));
 				let id = header.compute_id();
 				insert_header(&mut storage, header.clone());
 				hashes.push(id.hash);
@@ -486,9 +463,9 @@ mod tests {
 			// check that votes at #7 are computed correctly without cache
 			let expected_votes_at_7 = FinalityVotes {
 				votes: vec![
-					(validators_addresses[0].clone(), 3),
-					(validators_addresses[1].clone(), 3),
-					(validators_addresses[2].clone(), 1),
+					(ctx.addresses[0].clone(), 3),
+					(ctx.addresses[1].clone(), 3),
+					(ctx.addresses[2].clone(), 1),
 				]
 				.into_iter()
 				.collect(),
@@ -499,11 +476,11 @@ mod tests {
 				prepare_votes(
 					storage.cached_finality_votes(
 						&headers.get(5).unwrap().compute_id(),
-						&genesis().compute_id(),
+						&ctx.genesis.compute_id(),
 						|_| false,
 					),
 					Default::default(),
-					&validators_addresses.iter().collect(),
+					&ctx.addresses.iter().collect(),
 					id7,
 					headers.get(6).unwrap(),
 					None,
@@ -514,12 +491,9 @@ mod tests {
 
 			// cached votes at #5
 			let expected_votes_at_5 = FinalityVotes {
-				votes: vec![
-					(validators_addresses[0].clone(), 3),
-					(validators_addresses[1].clone(), 2),
-				]
-				.into_iter()
-				.collect(),
+				votes: vec![(ctx.addresses[0].clone(), 3), (ctx.addresses[1].clone(), 2)]
+					.into_iter()
+					.collect(),
 				ancestry: ancestry[..5].iter().cloned().collect(),
 			};
 			FinalityCache::<TestRuntime>::insert(hashes[4], expected_votes_at_5);
@@ -530,11 +504,11 @@ mod tests {
 				prepare_votes(
 					storage.cached_finality_votes(
 						&headers.get(5).unwrap().compute_id(),
-						&genesis().compute_id(),
+						&ctx.genesis.compute_id(),
 						|_| false,
 					),
 					Default::default(),
-					&validators_addresses.iter().collect(),
+					&ctx.addresses.iter().collect(),
 					id7,
 					headers.get(6).unwrap(),
 					None,
@@ -546,12 +520,9 @@ mod tests {
 			// when we're inserting header#7 and last finalized header is 3:
 			// check that votes at #7 are computed correctly with cache
 			let expected_votes_at_7 = FinalityVotes {
-				votes: vec![
-					(validators_addresses[1].clone(), 3),
-					(validators_addresses[2].clone(), 1),
-				]
-				.into_iter()
-				.collect(),
+				votes: vec![(ctx.addresses[1].clone(), 3), (ctx.addresses[2].clone(), 1)]
+					.into_iter()
+					.collect(),
 				ancestry: ancestry[3..7].iter().cloned().collect(),
 			};
 			assert_eq!(
@@ -562,7 +533,7 @@ mod tests {
 						|hash| *hash == hashes[2],
 					),
 					headers[2].compute_id(),
-					&validators_addresses.iter().collect(),
+					&ctx.addresses.iter().collect(),
 					id7,
 					headers.get(6).unwrap(),
 					None,

bridges/modules/ethereum/src/import.rs

@@ -162,17 +162,19 @@ pub fn header_import_requires_receipts<S: Storage>(
 mod tests {
 	use super::*;
 	use crate::mock::{
-		block_i, custom_block_i, custom_test_ext, genesis, signed_header, test_aura_config, test_validators_config,
-		validator, validators, validators_addresses, KeepSomeHeadersBehindBest, TestRuntime, GENESIS_STEP,
+		run_test, secret_to_address, test_aura_config, test_validators_config, validator, validators_addresses,
+		HeaderBuilder, KeepSomeHeadersBehindBest, TestRuntime, GAS_LIMIT,
 	};
 	use crate::validators::ValidatorsSource;
 	use crate::{BlocksToPrune, BridgeStorage, Headers, PruningRange};
 	use frame_support::{StorageMap, StorageValue};
-	use parity_crypto::publickey::KeyPair;
+	use secp256k1::SecretKey;
+
+	const TOTAL_VALIDATORS: usize = 3;
 
 	#[test]
 	fn rejects_finalized_block_competitors() {
-		custom_test_ext(genesis(), validators_addresses(3)).execute_with(|| {
+		run_test(TOTAL_VALIDATORS, |_| {
 			let mut storage = BridgeStorage::<TestRuntime>::new();
 			storage.finalize_and_prune_headers(
 				Some(HeaderId {
@@ -198,10 +200,9 @@ mod tests {
 
 	#[test]
 	fn rejects_known_header() {
-		custom_test_ext(genesis(), validators_addresses(3)).execute_with(|| {
-			let validators = validators(3);
+		run_test(TOTAL_VALIDATORS, |ctx| {
 			let mut storage = BridgeStorage::<TestRuntime>::new();
-			let block = block_i(1, &validators);
+			let header = HeaderBuilder::with_parent(&ctx.genesis).sign_by(&validator(1));
 			assert_eq!(
 				import_header(
 					&mut storage,
@@ -209,7 +210,7 @@ mod tests {
 					&test_aura_config(),
 					&test_validators_config(),
 					None,
-					block.clone(),
+					header.clone(),
 					None,
 				)
 				.map(|_| ()),
@@ -222,7 +223,7 @@ mod tests {
 					&test_aura_config(),
 					&test_validators_config(),
 					None,
-					block,
+					header,
 					None,
 				)
 				.map(|_| ()),
@@ -233,14 +234,13 @@ mod tests {
 
 	#[test]
 	fn import_header_works() {
-		custom_test_ext(genesis(), validators_addresses(3)).execute_with(|| {
+		run_test(TOTAL_VALIDATORS, |ctx| {
 			let validators_config = ValidatorsConfiguration::Multi(vec![
-				(0, ValidatorsSource::List(validators_addresses(3))),
+				(0, ValidatorsSource::List(ctx.addresses.clone())),
 				(1, ValidatorsSource::List(validators_addresses(2))),
 			]);
-			let validators = validators(3);
 			let mut storage = BridgeStorage::<TestRuntime>::new();
-			let header = block_i(1, &validators);
+			let header = HeaderBuilder::with_parent(&ctx.genesis).sign_by(&validator(1));
 			let hash = header.compute_hash();
 			assert_eq!(
 				import_header(
@@ -267,9 +267,9 @@ mod tests {
 
 	#[test]
 	fn headers_are_pruned_during_import() {
-		custom_test_ext(genesis(), validators_addresses(3)).execute_with(|| {
+		run_test(TOTAL_VALIDATORS, |ctx| {
 			let validators_config =
-				ValidatorsConfiguration::Single(ValidatorsSource::Contract([3; 20].into(), validators_addresses(3)));
+				ValidatorsConfiguration::Single(ValidatorsSource::Contract([3; 20].into(), ctx.addresses.clone()));
 			let validators = vec![validator(0), validator(1), validator(2)];
 			let mut storage = BridgeStorage::<TestRuntime>::new();
 
@@ -277,7 +277,9 @@ mod tests {
 			// => since we want to keep 10 finalized blocks, we aren't pruning anything
 			let mut latest_block_id = Default::default();
 			for i in 1..11 {
-				let header = block_i(i, &validators);
+				let header = HeaderBuilder::with_parent_number(i - 1).sign_by_set(&validators);
+				let parent_id = header.parent_id().unwrap();
+
 				let (rolling_last_block_id, finalized_blocks) = import_header(
 					&mut storage,
 					&mut KeepSomeHeadersBehindBest::default(),
@@ -289,26 +291,24 @@ mod tests {
 				)
 				.unwrap();
 				match i {
-					2..=10 => assert_eq!(
-						finalized_blocks,
-						vec![(block_i(i - 1, &validators).compute_id(), Some(100))],
-						"At {}",
-						i,
-					),
+					2..=10 => assert_eq!(finalized_blocks, vec![(parent_id, Some(100))], "At {}", i,),
 					_ => assert_eq!(finalized_blocks, vec![], "At {}", i),
 				}
 				latest_block_id = rolling_last_block_id;
 			}
-			assert!(storage.header(&genesis().compute_hash()).is_some());
+			assert!(storage.header(&ctx.genesis.compute_hash()).is_some());
 
 			// header 11 finalizes headers [10] AND schedules change
 			// => we prune header#0
-			let header11 = custom_block_i(11, &validators, |header| {
-				header.log_bloom = (&[0xff; 256]).into();
-				header.receipts_root = "2e60346495092587026484e868a5b3063749032b2ea3843844509a6320d7f951"
-					.parse()
-					.unwrap();
-			});
+			let header11 = HeaderBuilder::with_parent_number(10)
+				.log_bloom((&[0xff; 256]).into())
+				.receipts_root(
+					"ead6c772ba0083bbff497ba0f4efe47c199a2655401096c21ab7450b6c466d97"
+						.parse()
+						.unwrap(),
+				)
+				.sign_by_set(&validators);
+			let parent_id = header11.parent_id().unwrap();
 			let (rolling_last_block_id, finalized_blocks) = import_header(
 				&mut storage,
 				&mut KeepSomeHeadersBehindBest::default(),
@@ -321,29 +321,20 @@ mod tests {
 				)]),
 			)
 			.unwrap();
-			assert_eq!(
-				finalized_blocks,
-				vec![(block_i(10, &validators).compute_id(), Some(100))],
-			);
-			assert!(storage.header(&genesis().compute_hash()).is_none());
+			assert_eq!(finalized_blocks, vec![(parent_id, Some(100))],);
+			assert!(storage.header(&ctx.genesis.compute_hash()).is_none());
 			latest_block_id = rolling_last_block_id;
 
 			// and now let's say validators 1 && 2 went offline
 			// => in the range 12-25 no blocks are finalized, but we still continue to prune old headers
 			// until header#11 is met. we can't prune #11, because it schedules change
-			let mut step = 56;
+			let mut step = 56u64;
 			let mut expected_blocks = vec![(header11.compute_id(), Some(101))];
 			for i in 12..25 {
-				let header = Header {
-					number: i as _,
-					parent_hash: latest_block_id.hash,
-					gas_limit: 0x2000.into(),
-					author: validator(2).address(),
-					seal: vec![vec![step].into(), vec![].into()],
-					difficulty: i.into(),
-					..Default::default()
-				};
-				let header = signed_header(&validators, header, step as _);
+				let header = HeaderBuilder::with_parent_hash(latest_block_id.hash)
+					.difficulty(i.into())
+					.step(step)
+					.sign_by_set(&validators);
 				expected_blocks.push((header.compute_id(), Some(102)));
 				let (rolling_last_block_id, finalized_blocks) = import_header(
 					&mut storage,
@@ -370,16 +361,10 @@ mod tests {
 			// now let's insert block signed by validator 1
 			// => blocks 11..24 are finalized and blocks 11..14 are pruned
 			step -= 2;
-			let header = Header {
-				number: 25,
-				parent_hash: latest_block_id.hash,
-				gas_limit: 0x2000.into(),
-				author: validator(0).address(),
-				seal: vec![vec![step].into(), vec![].into()],
-				difficulty: 25.into(),
-				..Default::default()
-			};
-			let header = signed_header(&validators, header, step as _);
+			let header = HeaderBuilder::with_parent_hash(latest_block_id.hash)
+				.difficulty(25.into())
+				.step(step)
+				.sign_by_set(&validators);
 			let (_, finalized_blocks) = import_header(
 				&mut storage,
 				&mut KeepSomeHeadersBehindBest::default(),
@@ -403,18 +388,9 @@ mod tests {
 
 	fn import_custom_block<S: Storage>(
 		storage: &mut S,
-		validators: &[KeyPair],
-		number: u64,
-		step: u64,
-		customize: impl FnOnce(&mut Header),
+		validators: &[SecretKey],
+		header: Header,
 	) -> Result<HeaderId, Error> {
-		let header = custom_block_i(number, validators, |header| {
-			header.seal[0][0] = step as _;
-			header.author =
-				crate::validators::step_validator(&validators.iter().map(|kp| kp.address()).collect::<Vec<_>>(), step);
-			customize(header);
-		});
-		let header = signed_header(validators, header, step);
 		let id = header.compute_id();
 		import_header(
 			storage,
@@ -422,7 +398,7 @@ mod tests {
 			&test_aura_config(),
 			&ValidatorsConfiguration::Single(ValidatorsSource::Contract(
 				[0; 20].into(),
-				validators.iter().map(|kp| kp.address()).collect(),
+				validators.iter().map(secret_to_address).collect(),
 			)),
 			None,
 			header,
@@ -433,37 +409,41 @@ mod tests {
 
 	#[test]
 	fn import_of_non_best_block_may_finalize_blocks() {
-		const TOTAL_VALIDATORS: u8 = 3;
-		let validators_addresses = validators_addresses(TOTAL_VALIDATORS);
-		custom_test_ext(genesis(), validators_addresses.clone()).execute_with(move || {
-			let validators = validators(TOTAL_VALIDATORS);
+		run_test(TOTAL_VALIDATORS, |ctx| {
 			let mut storage = BridgeStorage::<TestRuntime>::new();
 
 			// insert headers (H1, validator1), (H2, validator1), (H3, validator1)
 			// making H3 the best header, without finalizing anything (we need 2 signatures)
 			let mut expected_best_block = Default::default();
 			for i in 1..4 {
-				let step = GENESIS_STEP + i * TOTAL_VALIDATORS as u64;
-				expected_best_block = import_custom_block(&mut storage, &validators, i, step, |header| {
-					header.author = validators_addresses[0];
-					header.seal[0][0] = step as u8;
-				})
+				let step = 1 + i * TOTAL_VALIDATORS as u64;
+				expected_best_block = import_custom_block(
+					&mut storage,
+					&ctx.validators,
+					HeaderBuilder::with_parent_number(i - 1)
+						.step(step)
+						.sign_by_set(&ctx.validators),
+				)
 				.unwrap();
 			}
 			let (best_block, best_difficulty) = storage.best_block();
 			assert_eq!(best_block, expected_best_block);
-			assert_eq!(storage.finalized_block(), genesis().compute_id());
+			assert_eq!(storage.finalized_block(), ctx.genesis.compute_id());
 
 			// insert headers (H1', validator1), (H2', validator2), finalizing H2, even though H3
 			// has better difficulty than H2' (because there are more steps involved)
 			let mut expected_finalized_block = Default::default();
-			let mut parent_hash = genesis().compute_hash();
+			let mut parent_hash = ctx.genesis.compute_hash();
 			for i in 1..3 {
-				let step = GENESIS_STEP + i;
-				let id = import_custom_block(&mut storage, &validators, i, step, |header| {
-					header.gas_limit += 1.into();
-					header.parent_hash = parent_hash;
-				})
+				let step = i;
+				let id = import_custom_block(
+					&mut storage,
+					&ctx.validators,
+					HeaderBuilder::with_parent_hash(parent_hash)
+						.step(step)
+						.gas_limit((GAS_LIMIT + 1).into())
+						.sign_by_set(&ctx.validators),
+				)
 				.unwrap();
 				parent_hash = id.hash;
 				if i == 1 {
@@ -479,83 +459,117 @@ mod tests {
 
 	#[test]
 	fn append_to_unfinalized_fork_fails() {
-		const TOTAL_VALIDATORS: u64 = 5;
-		let validators_addresses = validators_addresses(TOTAL_VALIDATORS as _);
-		custom_test_ext(genesis(), validators_addresses.clone()).execute_with(move || {
-			let validators = validators(TOTAL_VALIDATORS as _);
+		const VALIDATORS: u64 = 5;
+		run_test(VALIDATORS as usize, |ctx| {
 			let mut storage = BridgeStorage::<TestRuntime>::new();
 
 			// header1, authored by validator[2] is best common block between two competing forks
-			let header1 = import_custom_block(&mut storage, &validators, 1, GENESIS_STEP + 1, |_| ()).unwrap();
+			let header1 = import_custom_block(
+				&mut storage,
+				&ctx.validators,
+				HeaderBuilder::with_parent_number(0)
+					.step(2)
+					.sign_by_set(&ctx.validators),
+			)
+			.unwrap();
 			assert_eq!(storage.best_block().0, header1);
 			assert_eq!(storage.finalized_block().number, 0);
 
 			// validator[3] has authored header2 (nothing is finalized yet)
-			let header2 = import_custom_block(&mut storage, &validators, 2, GENESIS_STEP + 2, |_| ()).unwrap();
+			let header2 = import_custom_block(
+				&mut storage,
+				&ctx.validators,
+				HeaderBuilder::with_parent_number(1)
+					.step(3)
+					.sign_by_set(&ctx.validators),
+			)
+			.unwrap();
 			assert_eq!(storage.best_block().0, header2);
 			assert_eq!(storage.finalized_block().number, 0);
 
 			// validator[4] has authored header3 (header1 is finalized)
-			let header3 = import_custom_block(&mut storage, &validators, 3, GENESIS_STEP + 3, |_| ()).unwrap();
+			let header3 = import_custom_block(
+				&mut storage,
+				&ctx.validators,
+				HeaderBuilder::with_parent_number(2)
+					.step(4)
+					.sign_by_set(&ctx.validators),
+			)
+			.unwrap();
 			assert_eq!(storage.best_block().0, header3);
 			assert_eq!(storage.finalized_block(), header1);
 
 			// validator[4] has authored 4 blocks: header2'...header5' (header1 is still finalized)
-			let header2_1 = import_custom_block(&mut storage, &validators, 2, GENESIS_STEP + 3, |header| {
-				header.gas_limit += 1.into();
-			})
+			let header2_1 = import_custom_block(
+				&mut storage,
+				&ctx.validators,
+				HeaderBuilder::with_parent_number(1)
+					.gas_limit((GAS_LIMIT + 1).into())
+					.step(4)
+					.sign_by_set(&ctx.validators),
+			)
 			.unwrap();
 			let header3_1 = import_custom_block(
 				&mut storage,
-				&validators,
-				3,
-				GENESIS_STEP + 3 + TOTAL_VALIDATORS,
-				|header| {
-					header.parent_hash = header2_1.hash;
-				},
+				&ctx.validators,
+				HeaderBuilder::with_parent_hash(header2_1.hash)
+					.step(4 + VALIDATORS)
+					.sign_by_set(&ctx.validators),
 			)
 			.unwrap();
 			let header4_1 = import_custom_block(
 				&mut storage,
-				&validators,
-				4,
-				GENESIS_STEP + 3 + TOTAL_VALIDATORS * 2,
-				|header| {
-					header.parent_hash = header3_1.hash;
-				},
+				&ctx.validators,
+				HeaderBuilder::with_parent_hash(header3_1.hash)
+					.step(4 + VALIDATORS * 2)
+					.sign_by_set(&ctx.validators),
 			)
 			.unwrap();
 			let header5_1 = import_custom_block(
 				&mut storage,
-				&validators,
-				5,
-				GENESIS_STEP + 3 + TOTAL_VALIDATORS * 3,
-				|header| {
-					header.parent_hash = header4_1.hash;
-				},
+				&ctx.validators,
+				HeaderBuilder::with_parent_hash(header4_1.hash)
+					.step(4 + VALIDATORS * 3)
+					.sign_by_set(&ctx.validators),
 			)
 			.unwrap();
 			assert_eq!(storage.best_block().0, header5_1);
 			assert_eq!(storage.finalized_block(), header1);
 
 			// when we import header4 { parent = header3 }, authored by validator[0], header2 is finalized
-			let header4 = import_custom_block(&mut storage, &validators, 4, GENESIS_STEP + 4, |_| ()).unwrap();
+			let header4 = import_custom_block(
+				&mut storage,
+				&ctx.validators,
+				HeaderBuilder::with_parent_number(3)
+					.step(5)
+					.sign_by_set(&ctx.validators),
+			)
+			.unwrap();
 			assert_eq!(storage.best_block().0, header5_1);
 			assert_eq!(storage.finalized_block(), header2);
 
 			// when we import header5 { parent = header4 }, authored by validator[1], header3 is finalized
-			let _ = import_custom_block(&mut storage, &validators, 5, GENESIS_STEP + 5, |header| {
-				header.parent_hash = header4.hash;
-			})
+			let header5 = import_custom_block(
+				&mut storage,
+				&ctx.validators,
+				HeaderBuilder::with_parent_hash(header4.hash)
+					.step(6)
+					.sign_by_set(&ctx.validators),
+			)
 			.unwrap();
-			assert_eq!(storage.best_block().0, header5_1);
+			assert_eq!(storage.best_block().0, header5);
 			assert_eq!(storage.finalized_block(), header3);
 
 			// import of header2'' { parent = header1 } fails, because it has number < best_finalized
 			assert_eq!(
-				import_custom_block(&mut storage, &validators, 2, GENESIS_STEP + 3, |header| {
-					header.gas_limit += 2.into();
-				}),
+				import_custom_block(
+					&mut storage,
+					&ctx.validators,
+					HeaderBuilder::with_parent_number(1)
+						.gas_limit((GAS_LIMIT + 1).into())
+						.step(3)
+						.sign_by_set(&ctx.validators)
+				),
 				Err(Error::AncientHeader),
 			);
 
@@ -564,10 +578,11 @@ mod tests {
 			assert_eq!(
 				import_custom_block(
 					&mut storage,
-					&validators,
-					6,
-					GENESIS_STEP + 3 + TOTAL_VALIDATORS * 4,
-					|_| ()
+					&ctx.validators,
+					HeaderBuilder::with_parent_number(5)
+						.gas_limit((GAS_LIMIT + 1).into())
+						.step(5 + VALIDATORS * 4)
+						.sign_by_set(&ctx.validators),
 				),
 				Err(Error::TryingToFinalizeSibling),
 			);

bridges/modules/ethereum/src/lib.rs

@@ -37,9 +37,15 @@ mod import;
 mod validators;
 mod verification;
 
+#[cfg(feature = "runtime-benchmarks")]
+mod benchmarking;
+
 #[cfg(test)]
 mod mock;
 
+#[cfg(any(feature = "runtime-benchmarks", test))]
+mod test_utils;
+
 /// Maximal number of blocks we're pruning in single import call.
 const MAX_BLOCKS_TO_PRUNE_IN_SINGLE_IMPORT: u64 = 8;
 
@@ -464,32 +470,11 @@ decl_storage! {
 				"Initial validators set can't be empty",
 			);
 
-			let initial_hash = config.initial_header.compute_hash();
-			let initial_id = HeaderId {
-				number: config.initial_header.number,
-				hash: initial_hash,
-			};
-			BestBlock::put((initial_id, config.initial_difficulty));
-			FinalizedBlock::put(initial_id);
-			BlocksToPrune::put(PruningRange {
-				oldest_unpruned_block: config.initial_header.number,
-				oldest_block_to_keep: config.initial_header.number,
-			});
-			HeadersByNumber::insert(config.initial_header.number, vec![initial_hash]);
-			Headers::<T>::insert(initial_hash, StoredHeader {
-				submitter: None,
-				header: config.initial_header.clone(),
-				total_difficulty: config.initial_difficulty,
-				next_validators_set_id: 0,
-				last_signal_block: None,
-			});
-			NextValidatorsSetId::put(1);
-			ValidatorsSets::insert(0, ValidatorsSet {
-				validators: config.initial_validators.clone(),
-				signal_block: None,
-				enact_block: initial_id,
-			});
-			ValidatorsSetsRc::insert(0, 1);
+			initialize_storage::<T>(
+				&config.initial_header,
+				config.initial_difficulty,
+				&config.initial_validators,
+			);
 		})
 	}
 }
@@ -632,6 +617,13 @@ impl<T: Trait> BridgeStorage<T> {
 		// physically remove headers and (probably) obsolete validators sets
 		while let Some(hash) = blocks_at_number.pop() {
 			let header = Headers::<T>::take(&hash);
+			frame_support::debug::trace!(
+				target: "runtime",
+				"Pruning PoA header: ({}, {})",
+				number,
+				hash,
+			);
+
 			ScheduledChanges::remove(hash);
 			FinalityCache::<T>::remove(hash);
 			if let Some(header) = header {
@@ -830,6 +822,53 @@ impl<T: Trait> Storage for BridgeStorage<T> {
 	}
 }
 
+/// Initialize storage.
+pub(crate) fn initialize_storage<T: Trait>(
+	initial_header: &Header,
+	initial_difficulty: U256,
+	initial_validators: &[Address],
+) {
+	let initial_hash = initial_header.compute_hash();
+	frame_support::debug::trace!(
+		target: "runtime",
+		"Initializing bridge with PoA header: ({}, {})",
+		initial_header.number,
+		initial_hash,
+	);
+
+	let initial_id = HeaderId {
+		number: initial_header.number,
+		hash: initial_hash,
+	};
+	BestBlock::put((initial_id, initial_difficulty));
+	FinalizedBlock::put(initial_id);
+	BlocksToPrune::put(PruningRange {
+		oldest_unpruned_block: initial_header.number,
+		oldest_block_to_keep: initial_header.number,
+	});
+	HeadersByNumber::insert(initial_header.number, vec![initial_hash]);
+	Headers::<T>::insert(
+		initial_hash,
+		StoredHeader {
+			submitter: None,
+			header: initial_header.clone(),
+			total_difficulty: initial_difficulty,
+			next_validators_set_id: 0,
+			last_signal_block: None,
+		},
+	);
+	NextValidatorsSetId::put(1);
+	ValidatorsSets::insert(
+		0,
+		ValidatorsSet {
+			validators: initial_validators.to_vec(),
+			signal_block: None,
+			enact_block: initial_id,
+		},
+	);
+	ValidatorsSetsRc::insert(0, 1);
+}
+
 /// Verify that transaction is included into given finalized block.
 pub fn verify_transaction_finalized<S: Storage>(
 	storage: &S,
@@ -894,10 +933,13 @@ pub(crate) mod tests {
 	use super::*;
 	use crate::finality::FinalityAncestor;
 	use crate::mock::{
-		block_i, custom_block_i, custom_test_ext, genesis, insert_header, validators, validators_addresses, TestRuntime,
+		genesis, insert_header, run_test, run_test_with_genesis, validators_addresses, HeaderBuilder, TestRuntime,
+		GAS_LIMIT,
 	};
 	use primitives::compute_merkle_root;
 
+	const TOTAL_VALIDATORS: usize = 3;
+
 	fn example_tx() -> Vec<u8> {
 		vec![42]
 	}
@@ -919,14 +961,13 @@ pub(crate) mod tests {
 	}
 
 	fn with_headers_to_prune<T>(f: impl Fn(BridgeStorage<TestRuntime>) -> T) -> T {
-		custom_test_ext(genesis(), validators_addresses(3)).execute_with(|| {
-			let validators = validators(3);
+		run_test(TOTAL_VALIDATORS, |ctx| {
 			for i in 1..10 {
 				let mut headers_by_number = Vec::with_capacity(5);
 				for j in 0..5 {
-					let header = custom_block_i(i, &validators, |header| {
-						header.gas_limit = header.gas_limit + U256::from(j);
-					});
+					let header = HeaderBuilder::with_parent_number(i - 1)
+						.gas_limit((GAS_LIMIT + j).into())
+						.sign_by_set(&ctx.validators);
 					let hash = header.compute_hash();
 					headers_by_number.push(hash);
 					Headers::<TestRuntime>::insert(
@@ -1082,21 +1123,20 @@ pub(crate) mod tests {
 
 	#[test]
 	fn finality_votes_are_cached() {
-		custom_test_ext(genesis(), validators_addresses(3)).execute_with(|| {
+		run_test(TOTAL_VALIDATORS, |ctx| {
 			let mut storage = BridgeStorage::<TestRuntime>::new();
 			let interval = <TestRuntime as Trait>::FinalityVotesCachingInterval::get().unwrap();
 
 			// for all headers with number < interval, cache entry is not created
-			let validators = validators(3);
 			for i in 1..interval {
-				let header = block_i(i, &validators);
+				let header = HeaderBuilder::with_parent_number(i - 1).sign_by_set(&ctx.validators);
 				let id = header.compute_id();
 				insert_header(&mut storage, header);
 				assert_eq!(FinalityCache::<TestRuntime>::get(&id.hash), None);
 			}
 
 			// for header with number = interval, cache entry is created
-			let header_with_entry = block_i(interval, &validators);
+			let header_with_entry = HeaderBuilder::with_parent_number(interval - 1).sign_by_set(&ctx.validators);
 			let header_with_entry_hash = header_with_entry.compute_hash();
 			insert_header(&mut storage, header_with_entry);
 			assert_eq!(
@@ -1116,13 +1156,12 @@ pub(crate) mod tests {
 
 	#[test]
 	fn cached_finality_votes_finds_entry() {
-		custom_test_ext(genesis(), validators_addresses(3)).execute_with(|| {
+		run_test(TOTAL_VALIDATORS, |ctx| {
 			// insert 5 headers
-			let validators = validators(3);
 			let mut storage = BridgeStorage::<TestRuntime>::new();
 			let mut headers = Vec::new();
 			for i in 1..5 {
-				let header = block_i(i, &validators);
+				let header = HeaderBuilder::with_parent_number(i - 1).sign_by_set(&ctx.validators);
 				headers.push(header.clone());
 				insert_header(&mut storage, header);
 			}
@@ -1177,19 +1216,18 @@ pub(crate) mod tests {
 
 	#[test]
 	fn cached_finality_votes_stops_at_finalized_sibling() {
-		custom_test_ext(genesis(), validators_addresses(3)).execute_with(|| {
-			let validators = validators(3);
+		run_test(TOTAL_VALIDATORS, |ctx| {
 			let mut storage = BridgeStorage::<TestRuntime>::new();
 
 			// insert header1
-			let header1 = block_i(1, &validators);
+			let header1 = HeaderBuilder::with_parent_number(0).sign_by_set(&ctx.validators);
 			let header1_id = header1.compute_id();
 			insert_header(&mut storage, header1);
 
 			// insert header1' - sibling of header1
-			let header1s = custom_block_i(1, &validators, |header| {
-				header.gas_limit += 1.into();
-			});
+			let header1s = HeaderBuilder::with_parent_number(0)
+				.gas_limit((GAS_LIMIT + 1).into())
+				.sign_by_set(&ctx.validators);
 			let header1s_id = header1s.compute_id();
 			insert_header(&mut storage, header1s);
 
@@ -1214,7 +1252,7 @@ pub(crate) mod tests {
 
 	#[test]
 	fn verify_transaction_finalized_works_for_best_finalized_header() {
-		custom_test_ext(example_header(), validators_addresses(3)).execute_with(|| {
+		run_test_with_genesis(example_header(), TOTAL_VALIDATORS, |_| {
 			let storage = BridgeStorage::<TestRuntime>::new();
 			assert_eq!(
 				verify_transaction_finalized(&storage, example_header().compute_hash(), 0, &vec![example_tx()],),
@@ -1225,7 +1263,7 @@ pub(crate) mod tests {
 
 	#[test]
 	fn verify_transaction_finalized_works_for_best_finalized_header_ancestor() {
-		custom_test_ext(genesis(), validators_addresses(3)).execute_with(|| {
+		run_test(TOTAL_VALIDATORS, |_| {
 			let mut storage = BridgeStorage::<TestRuntime>::new();
 			insert_header(&mut storage, example_header_parent());
 			insert_header(&mut storage, example_header());
@@ -1239,7 +1277,7 @@ pub(crate) mod tests {
 
 	#[test]
 	fn verify_transaction_finalized_rejects_proof_with_missing_tx() {
-		custom_test_ext(example_header(), validators_addresses(3)).execute_with(|| {
+		run_test_with_genesis(example_header(), TOTAL_VALIDATORS, |_| {
 			let storage = BridgeStorage::<TestRuntime>::new();
 			assert_eq!(
 				verify_transaction_finalized(&storage, example_header().compute_hash(), 1, &vec![],),
@@ -1250,7 +1288,7 @@ pub(crate) mod tests {
 
 	#[test]
 	fn verify_transaction_finalized_rejects_unknown_header() {
-		custom_test_ext(genesis(), validators_addresses(3)).execute_with(|| {
+		run_test(TOTAL_VALIDATORS, |_| {
 			let storage = BridgeStorage::<TestRuntime>::new();
 			assert_eq!(
 				verify_transaction_finalized(&storage, example_header().compute_hash(), 1, &vec![],),
@@ -1261,7 +1299,7 @@ pub(crate) mod tests {
 
 	#[test]
 	fn verify_transaction_finalized_rejects_unfinalized_header() {
-		custom_test_ext(genesis(), validators_addresses(3)).execute_with(|| {
+		run_test(TOTAL_VALIDATORS, |_| {
 			let mut storage = BridgeStorage::<TestRuntime>::new();
 			insert_header(&mut storage, example_header_parent());
 			insert_header(&mut storage, example_header());
@@ -1274,7 +1312,7 @@ pub(crate) mod tests {
 
 	#[test]
 	fn verify_transaction_finalized_rejects_finalized_header_sibling() {
-		custom_test_ext(genesis(), validators_addresses(3)).execute_with(|| {
+		run_test(TOTAL_VALIDATORS, |_| {
 			let mut finalized_header_sibling = example_header();
 			finalized_header_sibling.timestamp = 1;
 			let finalized_header_sibling_hash = finalized_header_sibling.compute_hash();
@@ -1293,7 +1331,7 @@ pub(crate) mod tests {
 
 	#[test]
 	fn verify_transaction_finalized_rejects_finalized_header_uncle() {
-		custom_test_ext(genesis(), validators_addresses(3)).execute_with(|| {
+		run_test(TOTAL_VALIDATORS, |_| {
 			let mut finalized_header_uncle = example_header_parent();
 			finalized_header_uncle.timestamp = 1;
 			let finalized_header_uncle_hash = finalized_header_uncle.compute_hash();
@@ -1312,7 +1350,7 @@ pub(crate) mod tests {
 
 	#[test]
 	fn verify_transaction_finalized_rejects_invalid_proof() {
-		custom_test_ext(example_header(), validators_addresses(3)).execute_with(|| {
+		run_test_with_genesis(example_header(), TOTAL_VALIDATORS, |_| {
 			let storage = BridgeStorage::<TestRuntime>::new();
 			assert_eq!(
 				verify_transaction_finalized(

bridges/modules/ethereum/src/mock.rs

@@ -14,14 +14,15 @@
 // You should have received a copy of the GNU General Public License
 // along with Parity Bridges Common.  If not, see <http://www.gnu.org/licenses/>.
 
+pub use crate::test_utils::{validator_utils::*, HeaderBuilder, GAS_LIMIT};
+pub use primitives::signatures::secret_to_address;
+
 use crate::finality::FinalityVotes;
 use crate::validators::{ValidatorsConfiguration, ValidatorsSource};
-use crate::{AuraConfiguration, GenesisConfig, HeaderToImport, HeadersByNumber, PruningStrategy, Storage, Trait};
-use frame_support::StorageMap;
+use crate::{AuraConfiguration, GenesisConfig, HeaderToImport, PruningStrategy, Storage, Trait};
 use frame_support::{impl_outer_origin, parameter_types, weights::Weight};
-use parity_crypto::publickey::{sign, KeyPair, Secret};
-use primitives::{rlp_encode, H520};
 use primitives::{Address, Header, H256, U256};
+use secp256k1::SecretKey;
 use sp_runtime::{
 	testing::Header as SubstrateHeader,
 	traits::{BlakeTwo256, IdentityLookup},
@@ -84,8 +85,17 @@ impl Trait for TestRuntime {
 	type OnHeadersSubmitted = ();
 }
 
-/// Step of genesis header.
-pub const GENESIS_STEP: u64 = 42;
+/// Test context.
+pub struct TestContext {
+	/// Initial (genesis) header.
+	pub genesis: Header,
+	/// Number of initial validators.
+	pub total_validators: usize,
+	/// Secret keys of validators, ordered by validator index.
+	pub validators: Vec<SecretKey>,
+	/// Addresses of validators, ordered by validator index.
+	pub addresses: Vec<Address>,
+}
 
 /// Aura configuration that is used in tests by default.
 pub fn test_aura_config() -> AuraConfiguration {
@@ -108,72 +118,38 @@ pub fn test_validators_config() -> ValidatorsConfiguration {
 
 /// Genesis header that is used in tests by default.
 pub fn genesis() -> Header {
-	Header {
-		seal: vec![vec![GENESIS_STEP as _].into(), vec![].into()],
-		..Default::default()
-	}
+	HeaderBuilder::genesis().sign_by(&validator(0))
 }
 
-/// Build default i-th block, using data from runtime storage.
-pub fn block_i(number: u64, validators: &[KeyPair]) -> Header {
-	custom_block_i(number, validators, |_| {})
+/// Run test with default genesis header.
+pub fn run_test<T>(total_validators: usize, test: impl FnOnce(TestContext) -> T) -> T {
+	run_test_with_genesis(genesis(), total_validators, test)
 }
 
-/// Build custom i-th block, using data from runtime storage.
-pub fn custom_block_i(number: u64, validators: &[KeyPair], customize: impl FnOnce(&mut Header)) -> Header {
-	let validator_index: u8 = (number % (validators.len() as u64)) as _;
-	let mut header = Header {
-		number,
-		parent_hash: HeadersByNumber::get(number - 1).unwrap()[0].clone(),
-		gas_limit: 0x2000.into(),
-		author: validator(validator_index).address(),
-		seal: vec![vec![(number + GENESIS_STEP) as u8].into(), vec![].into()],
-		difficulty: number.into(),
-		..Default::default()
-	};
-	customize(&mut header);
-	signed_header(validators, header, number + GENESIS_STEP)
+/// Run test with default genesis header.
+pub fn run_test_with_genesis<T>(genesis: Header, total_validators: usize, test: impl FnOnce(TestContext) -> T) -> T {
+	let validators = validators(total_validators);
+	let addresses = validators_addresses(total_validators);
+	sp_io::TestExternalities::new(
+		GenesisConfig {
+			initial_header: genesis.clone(),
+			initial_difficulty: 0.into(),
+			initial_validators: addresses.clone(),
+		}
+		.build_storage::<TestRuntime>()
+		.unwrap(),
+	)
+	.execute_with(|| {
+		test(TestContext {
+			genesis,
+			total_validators,
+			validators,
+			addresses,
+		})
+	})
 }
 
-/// Build signed header from given header.
-pub fn signed_header(validators: &[KeyPair], mut header: Header, step: u64) -> Header {
-	let message = header.seal_hash(false).unwrap();
-	let validator_index = (step % validators.len() as u64) as usize;
-	let signature = sign(validators[validator_index].secret(), &message.as_fixed_bytes().into()).unwrap();
-	let signature: [u8; 65] = signature.into();
-	let signature = H520::from(signature);
-	header.seal[1] = rlp_encode(&signature);
-	header
-}
-
-/// Return key pair of given test validator.
-pub fn validator(index: u8) -> KeyPair {
-	KeyPair::from_secret(Secret::from([index + 1; 32])).unwrap()
-}
-
-/// Return key pairs of all test validators.
-pub fn validators(count: u8) -> Vec<KeyPair> {
-	(0..count).map(validator).collect()
-}
-
-/// Return addresses of all test validators.
-pub fn validators_addresses(count: u8) -> Vec<Address> {
-	(0..count).map(|i| validator(i).address()).collect()
-}
-
-/// Prepare externalities to start with custom initial header.
-pub fn custom_test_ext(initial_header: Header, initial_validators: Vec<Address>) -> sp_io::TestExternalities {
-	let t = GenesisConfig {
-		initial_header,
-		initial_difficulty: 0.into(),
-		initial_validators,
-	}
-	.build_storage::<TestRuntime>()
-	.unwrap();
-	sp_io::TestExternalities::new(t)
-}
-
-/// Insert header into storage.
+/// Insert unverified header into storage.
 pub fn insert_header<S: Storage>(storage: &mut S, header: Header) {
 	storage.insert_header(HeaderToImport {
 		context: storage.import_context(None, &header.parent_hash).unwrap(),

bridges/modules/ethereum/src/test_utils.rs

@@ -0,0 +1,233 @@
+// Copyright 2019-2020 Parity Technologies (UK) Ltd.
+// This file is part of Parity Bridges Common.
+
+// Parity Bridges Common is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Parity Bridges Common is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Parity Bridges Common.  If not, see <http://www.gnu.org/licenses/>.
+
+//! Utilities for testing and benchmarking the Ethereum Bridge Pallet.
+//!
+//! Although the name implies that it is used by tests, it shouldn't be be used _directly_ by tests.
+//! Instead these utilities should be used by the Mock runtime, which in turn is used by tests.
+//!
+//! On the other hand, they may be used directly by the bechmarking module.
+
+use crate::verification::calculate_score;
+
+use primitives::{
+	rlp_encode,
+	signatures::{secret_to_address, sign, SignHeader},
+	Address, Bloom, Header, SealedEmptyStep, H256, U256,
+};
+use secp256k1::SecretKey;
+use sp_std::prelude::*;
+
+/// Gas limit valid in test environment.
+pub const GAS_LIMIT: u64 = 0x2000;
+
+/// Test header builder.
+pub struct HeaderBuilder {
+	header: Header,
+	parent_header: Header,
+}
+
+impl HeaderBuilder {
+	/// Creates default genesis header.
+	pub fn genesis() -> Self {
+		let current_step = 0u64;
+		Self {
+			header: Header {
+				gas_limit: GAS_LIMIT.into(),
+				seal: vec![primitives::rlp_encode(&current_step), vec![]],
+				..Default::default()
+			},
+			parent_header: Default::default(),
+		}
+	}
+
+	/// Creates default header on top of parent with given hash.
+	#[cfg(test)]
+	pub fn with_parent_hash(parent_hash: H256) -> Self {
+		use crate::mock::TestRuntime;
+		use crate::Headers;
+		use frame_support::StorageMap;
+
+		let parent_header = Headers::<TestRuntime>::get(&parent_hash).unwrap().header;
+		Self::with_parent(&parent_header)
+	}
+
+	/// Creates default header on top of parent with given number. First parent is selected.
+	#[cfg(test)]
+	pub fn with_parent_number(parent_number: u64) -> Self {
+		use crate::HeadersByNumber;
+		use frame_support::StorageMap;
+
+		let parent_hash = HeadersByNumber::get(parent_number).unwrap()[0].clone();
+		Self::with_parent_hash(parent_hash)
+	}
+
+	/// Creates default header on top of non-existent parent.
+	#[cfg(test)]
+	pub fn with_number(number: u64) -> Self {
+		Self::with_parent(&Header {
+			number: number - 1,
+			seal: vec![primitives::rlp_encode(&(number - 1)), vec![]],
+			..Default::default()
+		})
+	}
+
+	/// Creates default header on top of given parent.
+	pub fn with_parent(parent_header: &Header) -> Self {
+		let parent_step = parent_header.step().unwrap();
+		let current_step = parent_step + 1;
+		Self {
+			header: Header {
+				parent_hash: parent_header.compute_hash(),
+				number: parent_header.number + 1,
+				gas_limit: GAS_LIMIT.into(),
+				seal: vec![primitives::rlp_encode(&current_step), vec![]],
+				difficulty: calculate_score(parent_step, current_step, 0),
+				..Default::default()
+			},
+			parent_header: parent_header.clone(),
+		}
+	}
+
+	/// Update step of this header.
+	pub fn step(mut self, step: u64) -> Self {
+		let parent_step = self.parent_header.step();
+		self.header.seal[0] = rlp_encode(&step);
+		self.header.difficulty = parent_step
+			.map(|parent_step| calculate_score(parent_step, step, 0))
+			.unwrap_or_default();
+		self
+	}
+
+	/// Adds empty steps to this header.
+	pub fn empty_steps(mut self, empty_steps: &[(&SecretKey, u64)]) -> Self {
+		let sealed_empty_steps = empty_steps
+			.into_iter()
+			.map(|(author, step)| {
+				let mut empty_step = SealedEmptyStep {
+					step: *step,
+					signature: Default::default(),
+				};
+				let message = empty_step.message(&self.header.parent_hash);
+				let signature: [u8; 65] = sign(author, message).into();
+				empty_step.signature = signature.into();
+				empty_step
+			})
+			.collect::<Vec<_>>();
+
+		// by default in test configuration headers are generated without empty steps seal
+		if self.header.seal.len() < 3 {
+			self.header.seal.push(Vec::new());
+		}
+
+		self.header.seal[2] = SealedEmptyStep::rlp_of(&sealed_empty_steps);
+		self
+	}
+
+	/// Update difficulty field of this header.
+	pub fn difficulty(mut self, difficulty: U256) -> Self {
+		self.header.difficulty = difficulty;
+		self
+	}
+
+	/// Update extra data field of this header.
+	pub fn extra_data(mut self, extra_data: Vec<u8>) -> Self {
+		self.header.extra_data = extra_data;
+		self
+	}
+
+	/// Update gas limit field of this header.
+	pub fn gas_limit(mut self, gas_limit: U256) -> Self {
+		self.header.gas_limit = gas_limit;
+		self
+	}
+
+	/// Update gas used field of this header.
+	pub fn gas_used(mut self, gas_used: U256) -> Self {
+		self.header.gas_used = gas_used;
+		self
+	}
+
+	/// Update log bloom field of this header.
+	pub fn log_bloom(mut self, log_bloom: Bloom) -> Self {
+		self.header.log_bloom = log_bloom;
+		self
+	}
+
+	/// Update receipts root field of this header.
+	pub fn receipts_root(mut self, receipts_root: H256) -> Self {
+		self.header.receipts_root = receipts_root;
+		self
+	}
+
+	/// Update timestamp field of this header.
+	pub fn timestamp(mut self, timestamp: u64) -> Self {
+		self.header.timestamp = timestamp;
+		self
+	}
+
+	/// Signs header by given author.
+	pub fn sign_by(self, author: &SecretKey) -> Header {
+		self.header.sign_by(author)
+	}
+
+	/// Signs header by given authors set.
+	pub fn sign_by_set(self, authors: &[SecretKey]) -> Header {
+		self.header.sign_by_set(authors)
+	}
+}
+
+/// Helper function for getting a genesis header which has been signed by an authority.
+pub fn build_genesis_header(author: &SecretKey) -> Header {
+	let genesis = HeaderBuilder::genesis();
+	genesis.header.sign_by(&author)
+}
+
+/// Helper function for building a custom child header which has been signed by an authority.
+pub fn build_custom_header<F>(author: &SecretKey, previous: &Header, customize_header: F) -> Header
+where
+	F: FnOnce(Header) -> Header,
+{
+	let new_header = HeaderBuilder::with_parent(&previous);
+	let custom_header = customize_header(new_header.header);
+	custom_header.sign_by(author)
+}
+
+pub mod validator_utils {
+	use super::*;
+
+	/// Return key pair of given test validator.
+	pub fn validator(index: usize) -> SecretKey {
+		let mut raw_secret = [0u8; 32];
+		raw_secret[..8].copy_from_slice(&(index + 1).to_le_bytes());
+		SecretKey::parse(&raw_secret).unwrap()
+	}
+
+	/// Return key pairs of all test validators.
+	pub fn validators(count: usize) -> Vec<SecretKey> {
+		(0..count).map(validator).collect()
+	}
+
+	/// Return address of test validator.
+	pub fn validator_address(index: usize) -> Address {
+		secret_to_address(&validator(index))
+	}
+
+	/// Return addresses of all test validators.
+	pub fn validators_addresses(count: usize) -> Vec<Address> {
+		(0..count).map(validator_address).collect()
+	}
+}

bridges/modules/ethereum/src/validators.rs

@@ -273,19 +273,16 @@ impl ValidatorsSource {
 	}
 }
 
-/// Get validator that should author the block at given step.
-pub fn step_validator(header_validators: &[Address], header_step: u64) -> Address {
-	header_validators[(header_step % header_validators.len() as u64) as usize]
-}
-
 #[cfg(test)]
 pub(crate) mod tests {
 	use super::*;
-	use crate::mock::{custom_test_ext, genesis, validators_addresses, TestRuntime};
+	use crate::mock::{run_test, validators_addresses, TestRuntime};
 	use crate::{BridgeStorage, Headers, ScheduledChange, ScheduledChanges, StoredHeader};
 	use frame_support::StorageMap;
 	use primitives::{TransactionOutcome, H256};
 
+	const TOTAL_VALIDATORS: usize = 3;
+
 	pub(crate) fn validators_change_recept(parent_hash: H256) -> Receipt {
 		Receipt {
 			gas_used: 0.into(),
@@ -425,7 +422,7 @@ pub(crate) mod tests {
 	}
 
 	fn try_finalize_with_scheduled_change(scheduled_at: Option<HeaderId>) -> Option<ChangeToEnact> {
-		custom_test_ext(genesis(), validators_addresses(3)).execute_with(|| {
+		run_test(TOTAL_VALIDATORS, |_| {
 			let config = ValidatorsConfiguration::Single(ValidatorsSource::Contract(Default::default(), Vec::new()));
 			let validators = Validators::new(&config);
 			let storage = BridgeStorage::<TestRuntime>::new();

bridges/modules/ethereum/src/verification.rs

@@ -15,10 +15,12 @@
 // along with Parity Bridges Common.  If not, see <http://www.gnu.org/licenses/>.
 
 use crate::error::Error;
-use crate::validators::{step_validator, Validators, ValidatorsConfiguration};
+use crate::validators::{Validators, ValidatorsConfiguration};
 use crate::{AuraConfiguration, ImportContext, PoolConfiguration, ScheduledChange, Storage};
 use codec::Encode;
-use primitives::{public_to_address, Address, Header, HeaderId, Receipt, SealedEmptyStep, H256, H520, U128, U256};
+use primitives::{
+	public_to_address, step_validator, Address, Header, HeaderId, Receipt, SealedEmptyStep, H256, H520, U128, U256,
+};
 use sp_io::crypto::secp256k1_ecdsa_recover;
 use sp_std::{vec, vec::Vec};
 
@@ -157,9 +159,16 @@ pub fn verify_aura_header<S: Storage>(
 	contextless_checks(config, header)?;
 
 	// the rest of checks requires access to the parent header
-	let context = storage
-		.import_context(submitter, &header.parent_hash)
-		.ok_or(Error::MissingParentBlock)?;
+	let context = storage.import_context(submitter, &header.parent_hash).ok_or_else(|| {
+		frame_support::debug::warn!(
+			target: "runtime",
+			"Missing parent PoA block: ({:?}, {})",
+			header.number.checked_sub(1),
+			header.parent_hash,
+		);
+
+		Error::MissingParentBlock
+	})?;
 	let header_step = contextual_checks(config, &context, None, header)?;
 	validator_checks(config, &context.validators_set().validators, header, header_step)?;
 
@@ -263,7 +272,7 @@ fn validator_checks(
 	header: &Header,
 	header_step: u64,
 ) -> Result<(), Error> {
-	let expected_validator = step_validator(validators, header_step);
+	let expected_validator = *step_validator(validators, header_step);
 	if header.author != expected_validator {
 		return Err(Error::NotValidator);
 	}
@@ -282,7 +291,7 @@ fn validator_checks(
 
 /// Returns expected number of seal fields in the header.
 fn expected_header_seal_fields(config: &AuraConfiguration, header: &Header) -> usize {
-	if header.number >= config.empty_steps_transition {
+	if header.number != u64::max_value() && header.number >= config.empty_steps_transition {
 		3
 	} else {
 		2
@@ -291,13 +300,13 @@ fn expected_header_seal_fields(config: &AuraConfiguration, header: &Header) -> u
 
 /// Verify single sealed empty step.
 fn verify_empty_step(parent_hash: &H256, step: &SealedEmptyStep, validators: &[Address]) -> bool {
-	let expected_validator = step_validator(validators, step.step);
+	let expected_validator = *step_validator(validators, step.step);
 	let message = step.message(parent_hash);
 	verify_signature(&expected_validator, &step.signature, &message)
 }
 
 /// Chain scoring: total weight is sqrt(U256::max_value())*height - step
-fn calculate_score(parent_step: u64, current_step: u64, current_empty_steps: usize) -> U256 {
+pub(crate) fn calculate_score(parent_step: u64, current_step: u64, current_empty_steps: usize) -> U256 {
 	U256::from(U128::max_value()) + U256::from(parent_step) - U256::from(current_step) + U256::from(current_empty_steps)
 }
 
@@ -344,8 +353,8 @@ fn find_next_validators_signal<S: Storage>(storage: &S, context: &ImportContext<
 mod tests {
 	use super::*;
 	use crate::mock::{
-		block_i, custom_block_i, custom_test_ext, genesis, insert_header, signed_header, test_aura_config, validator,
-		validators_addresses, AccountId, TestRuntime,
+		insert_header, run_test_with_genesis, test_aura_config, validator, validator_address, validators_addresses,
+		AccountId, HeaderBuilder, TestRuntime, GAS_LIMIT,
 	};
 	use crate::validators::{tests::validators_change_recept, ValidatorsSource};
 	use crate::{
@@ -353,25 +362,18 @@ mod tests {
 		ScheduledChanges, ValidatorsSet, ValidatorsSets,
 	};
 	use frame_support::{StorageMap, StorageValue};
-	use parity_crypto::publickey::{sign, KeyPair};
 	use primitives::{rlp_encode, TransactionOutcome, H520};
+	use secp256k1::SecretKey;
 
-	fn sealed_empty_step(validators: &[KeyPair], parent_hash: &H256, step: u64) -> SealedEmptyStep {
-		let mut empty_step = SealedEmptyStep {
-			step,
-			signature: Default::default(),
-		};
-		let message = empty_step.message(parent_hash);
-		let validator_index = (step % validators.len() as u64) as usize;
-		let signature: [u8; 65] = sign(validators[validator_index].secret(), &message.as_fixed_bytes().into())
-			.unwrap()
-			.into();
-		empty_step.signature = signature.into();
-		empty_step
+	const GENESIS_STEP: u64 = 42;
+	const TOTAL_VALIDATORS: usize = 3;
+
+	fn genesis() -> Header {
+		HeaderBuilder::genesis().step(GENESIS_STEP).sign_by(&validator(0))
 	}
 
 	fn verify_with_config(config: &AuraConfiguration, header: &Header) -> Result<ImportContext<AccountId>, Error> {
-		custom_test_ext(genesis(), validators_addresses(3)).execute_with(|| {
+		run_test_with_genesis(genesis(), TOTAL_VALIDATORS, |_| {
 			let storage = BridgeStorage::<TestRuntime>::new();
 			verify_aura_header(&storage, &config, None, header)
 		})
@@ -382,17 +384,17 @@ mod tests {
 	}
 
 	fn default_accept_into_pool(
-		mut make_header: impl FnMut(&[KeyPair]) -> (Header, Option<Vec<Receipt>>),
+		mut make_header: impl FnMut(&[SecretKey]) -> (Header, Option<Vec<Receipt>>),
 	) -> Result<(Vec<Vec<u8>>, Vec<Vec<u8>>), Error> {
-		custom_test_ext(genesis(), validators_addresses(3)).execute_with(|| {
+		run_test_with_genesis(genesis(), TOTAL_VALIDATORS, |_| {
 			let validators = vec![validator(0), validator(1), validator(2)];
 			let mut storage = BridgeStorage::<TestRuntime>::new();
-			let block1 = block_i(1, &validators);
+			let block1 = HeaderBuilder::with_parent_number(0).sign_by_set(&validators);
 			insert_header(&mut storage, block1);
-			let block2 = block_i(2, &validators);
+			let block2 = HeaderBuilder::with_parent_number(1).sign_by_set(&validators);
 			let block2_id = block2.compute_id();
 			insert_header(&mut storage, block2);
-			let block3 = block_i(3, &validators);
+			let block3 = HeaderBuilder::with_parent_number(2).sign_by_set(&validators);
 			insert_header(&mut storage, block3);
 
 			FinalizedBlock::put(block2_id);
@@ -468,32 +470,26 @@ mod tests {
 	#[test]
 	fn verifies_header_number() {
 		// when number is u64::max_value()
-		let mut header = Header {
-			seal: vec![vec![].into(), vec![].into(), vec![].into()],
-			number: u64::max_value(),
-			..Default::default()
-		};
+		let header = HeaderBuilder::with_number(u64::max_value()).sign_by(&validator(0));
 		assert_eq!(default_verify(&header), Err(Error::RidiculousNumber));
 
 		// when header is < u64::max_value()
-		header.seal = vec![vec![].into(), vec![].into()];
-		header.number -= 1;
+		let header = HeaderBuilder::with_number(u64::max_value() - 1).sign_by(&validator(0));
 		assert_ne!(default_verify(&header), Err(Error::RidiculousNumber));
 	}
 
 	#[test]
 	fn verifies_gas_used() {
 		// when gas used is larger than gas limit
-		let mut header = Header {
-			seal: vec![vec![].into(), vec![].into()],
-			gas_used: 1.into(),
-			gas_limit: 0.into(),
-			..Default::default()
-		};
+		let header = HeaderBuilder::with_number(1)
+			.gas_used((GAS_LIMIT + 1).into())
+			.sign_by(&validator(0));
 		assert_eq!(default_verify(&header), Err(Error::TooMuchGasUsed));
 
 		// when gas used is less than gas limit
-		header.gas_limit = 1.into();
+		let header = HeaderBuilder::with_number(1)
+			.gas_used((GAS_LIMIT - 1).into())
+			.sign_by(&validator(0));
 		assert_ne!(default_verify(&header), Err(Error::TooMuchGasUsed));
 	}
 
@@ -504,67 +500,62 @@ mod tests {
 		config.max_gas_limit = 200.into();
 
 		// when limit is lower than expected
-		let mut header = Header {
-			seal: vec![vec![].into(), vec![].into()],
-			gas_limit: 50.into(),
-			..Default::default()
-		};
+		let header = HeaderBuilder::with_number(1)
+			.gas_limit(50.into())
+			.sign_by(&validator(0));
 		assert_eq!(verify_with_config(&config, &header), Err(Error::InvalidGasLimit));
 
 		// when limit is larger than expected
-		header.gas_limit = 250.into();
+		let header = HeaderBuilder::with_number(1)
+			.gas_limit(250.into())
+			.sign_by(&validator(0));
 		assert_eq!(verify_with_config(&config, &header), Err(Error::InvalidGasLimit));
 
 		// when limit is within expected range
-		header.gas_limit = 150.into();
+		let header = HeaderBuilder::with_number(1)
+			.gas_limit(150.into())
+			.sign_by(&validator(0));
 		assert_ne!(verify_with_config(&config, &header), Err(Error::InvalidGasLimit));
 	}
 
 	#[test]
 	fn verifies_extra_data_len() {
 		// when extra data is too large
-		let mut header = Header {
-			seal: vec![vec![].into(), vec![].into()],
-			gas_limit: test_aura_config().min_gas_limit,
-			extra_data: std::iter::repeat(42).take(1000).collect::<Vec<_>>().into(),
-			number: 1,
-			..Default::default()
-		};
+		let header = HeaderBuilder::with_number(1)
+			.extra_data(std::iter::repeat(42).take(1000).collect::<Vec<_>>())
+			.sign_by(&validator(0));
 		assert_eq!(default_verify(&header), Err(Error::ExtraDataOutOfBounds));
 
 		// when extra data size is OK
-		header.extra_data = std::iter::repeat(42).take(10).collect::<Vec<_>>().into();
+		let header = HeaderBuilder::with_number(1)
+			.extra_data(std::iter::repeat(42).take(10).collect::<Vec<_>>())
+			.sign_by(&validator(0));
 		assert_ne!(default_verify(&header), Err(Error::ExtraDataOutOfBounds));
 	}
 
 	#[test]
 	fn verifies_timestamp() {
 		// when timestamp overflows i32
-		let mut header = Header {
-			seal: vec![vec![].into(), vec![].into()],
-			gas_limit: test_aura_config().min_gas_limit,
-			timestamp: i32::max_value() as u64 + 1,
-			..Default::default()
-		};
+		let header = HeaderBuilder::with_number(1)
+			.timestamp(i32::max_value() as u64 + 1)
+			.sign_by(&validator(0));
 		assert_eq!(default_verify(&header), Err(Error::TimestampOverflow));
 
 		// when timestamp doesn't overflow i32
-		header.timestamp -= 1;
+		let header = HeaderBuilder::with_number(1)
+			.timestamp(i32::max_value() as u64)
+			.sign_by(&validator(0));
 		assert_ne!(default_verify(&header), Err(Error::TimestampOverflow));
 	}
 
 	#[test]
 	fn verifies_parent_existence() {
 		// when there's no parent in the storage
-		let mut header = Header {
-			seal: vec![vec![].into(), vec![].into()],
-			gas_limit: test_aura_config().min_gas_limit,
-			..Default::default()
-		};
+		let header = HeaderBuilder::with_number(1).sign_by(&validator(0));
 		assert_eq!(default_verify(&header), Err(Error::MissingParentBlock));
 
 		// when parent is in the storage
-		header.parent_hash = genesis().compute_hash();
+		let header = HeaderBuilder::with_parent(&genesis()).sign_by(&validator(0));
 		assert_ne!(default_verify(&header), Err(Error::MissingParentBlock));
 	}
 
@@ -580,11 +571,11 @@ mod tests {
 		assert_eq!(default_verify(&header), Err(Error::MissingStep));
 
 		// when step is the same as for the parent block
-		header.seal = vec![vec![42].into(), vec![].into()];
+		header.seal[0] = rlp_encode(&42u64);
 		assert_eq!(default_verify(&header), Err(Error::DoubleVote));
 
 		// when step is OK
-		header.seal = vec![vec![43].into(), vec![].into()];
+		header.seal[0] = rlp_encode(&43u64);
 		assert_ne!(default_verify(&header), Err(Error::DoubleVote));
 
 		// now check with validate_step check enabled
@@ -592,52 +583,47 @@ mod tests {
 		config.validate_step_transition = 0;
 
 		// when step is lesser that for the parent block
+		header.seal[0] = rlp_encode(&40u64);
 		header.seal = vec![vec![40].into(), vec![].into()];
 		assert_eq!(verify_with_config(&config, &header), Err(Error::DoubleVote));
 
 		// when step is OK
-		header.seal = vec![vec![44].into(), vec![].into()];
+		header.seal[0] = rlp_encode(&44u64);
 		assert_ne!(verify_with_config(&config, &header), Err(Error::DoubleVote));
 	}
 
 	#[test]
 	fn verifies_empty_step() {
-		let validators = vec![validator(0), validator(1), validator(2)];
 		let mut config = test_aura_config();
 		config.empty_steps_transition = 0;
 
 		// when empty step duplicates parent step
-		let mut header = Header {
-			seal: vec![
-				vec![45].into(),
-				vec![142].into(),
-				SealedEmptyStep::rlp_of(&[sealed_empty_step(&validators, &genesis().compute_hash(), 42)]),
-			],
-			gas_limit: test_aura_config().min_gas_limit,
-			parent_hash: genesis().compute_hash(),
-			..Default::default()
-		};
+		let header = HeaderBuilder::with_parent(&genesis())
+			.empty_steps(&[(&validator(0), GENESIS_STEP)])
+			.step(GENESIS_STEP + 3)
+			.sign_by(&validator(3));
 		assert_eq!(verify_with_config(&config, &header), Err(Error::InsufficientProof));
 
 		// when empty step signature check fails
-		let mut wrong_sealed_empty_step = sealed_empty_step(&validators, &genesis().compute_hash(), 43);
-		wrong_sealed_empty_step.signature = Default::default();
-		header.seal[2] = SealedEmptyStep::rlp_of(&[wrong_sealed_empty_step]);
+		let header = HeaderBuilder::with_parent(&genesis())
+			.empty_steps(&[(&validator(100), GENESIS_STEP + 1)])
+			.step(GENESIS_STEP + 3)
+			.sign_by(&validator(3));
 		assert_eq!(verify_with_config(&config, &header), Err(Error::InsufficientProof));
 
 		// when we are accepting strict empty steps and they come not in order
 		config.strict_empty_steps_transition = 0;
-		header.seal[2] = SealedEmptyStep::rlp_of(&[
-			sealed_empty_step(&validators, &genesis().compute_hash(), 44),
-			sealed_empty_step(&validators, &genesis().compute_hash(), 43),
-		]);
+		let header = HeaderBuilder::with_parent(&genesis())
+			.empty_steps(&[(&validator(2), GENESIS_STEP + 2), (&validator(1), GENESIS_STEP + 1)])
+			.step(GENESIS_STEP + 3)
+			.sign_by(&validator(3));
 		assert_eq!(verify_with_config(&config, &header), Err(Error::InsufficientProof));
 
 		// when empty steps are OK
-		header.seal[2] = SealedEmptyStep::rlp_of(&[
-			sealed_empty_step(&validators, &genesis().compute_hash(), 43),
-			sealed_empty_step(&validators, &genesis().compute_hash(), 44),
-		]);
+		let header = HeaderBuilder::with_parent(&genesis())
+			.empty_steps(&[(&validator(1), GENESIS_STEP + 1), (&validator(2), GENESIS_STEP + 2)])
+			.step(GENESIS_STEP + 3)
+			.sign_by(&validator(3));
 		assert_ne!(verify_with_config(&config, &header), Err(Error::InsufficientProof));
 	}
 
@@ -647,33 +633,19 @@ mod tests {
 		config.validate_score_transition = 0;
 
 		// when chain score is invalid
-		let mut header = Header {
-			seal: vec![vec![43].into(), vec![].into()],
-			gas_limit: test_aura_config().min_gas_limit,
-			parent_hash: genesis().compute_hash(),
-			..Default::default()
-		};
+		let header = HeaderBuilder::with_parent(&genesis())
+			.difficulty(100.into())
+			.sign_by(&validator(0));
 		assert_eq!(verify_with_config(&config, &header), Err(Error::InvalidDifficulty));
 
 		// when chain score is accepted
-		header.difficulty = calculate_score(42, 43, 0);
+		let header = HeaderBuilder::with_parent(&genesis()).sign_by(&validator(0));
 		assert_ne!(verify_with_config(&config, &header), Err(Error::InvalidDifficulty));
 	}
 
 	#[test]
 	fn verifies_validator() {
-		let validators = vec![validator(0), validator(1), validator(2)];
-		let good_header = signed_header(
-			&validators,
-			Header {
-				author: validators[1].address().as_fixed_bytes().into(),
-				seal: vec![vec![43].into(), vec![].into()],
-				gas_limit: test_aura_config().min_gas_limit,
-				parent_hash: genesis().compute_hash(),
-				..Default::default()
-			},
-			43,
-		);
+		let good_header = HeaderBuilder::with_parent(&genesis()).sign_by(&validator(1));
 
 		// when header author is invalid
 		let mut header = good_header.clone();
@@ -693,7 +665,7 @@ mod tests {
 	fn pool_verifies_known_blocks() {
 		// when header is known
 		assert_eq!(
-			default_accept_into_pool(|validators| (block_i(3, validators), None)),
+			default_accept_into_pool(|validators| (HeaderBuilder::with_parent_number(2).sign_by_set(validators), None)),
 			Err(Error::KnownHeader),
 		);
 	}
@@ -703,7 +675,9 @@ mod tests {
 		// when header number is less than finalized
 		assert_eq!(
 			default_accept_into_pool(|validators| (
-				custom_block_i(2, validators, |header| header.gas_limit += 1.into()),
+				HeaderBuilder::with_parent_number(1)
+					.gas_limit((GAS_LIMIT + 1).into())
+					.sign_by_set(validators),
 				None,
 			),),
 			Err(Error::AncientHeader),
@@ -731,7 +705,7 @@ mod tests {
 	fn pool_rejects_headers_with_redundant_receipts() {
 		assert_eq!(
 			default_accept_into_pool(|validators| (
-				block_i(4, validators),
+				HeaderBuilder::with_parent_number(3).sign_by_set(validators),
 				Some(vec![Receipt {
 					gas_used: 1.into(),
 					log_bloom: (&[0xff; 256]).into(),
@@ -747,7 +721,7 @@ mod tests {
 	fn pool_verifies_future_block_number() {
 		// when header is too far from the future
 		assert_eq!(
-			default_accept_into_pool(|validators| (custom_block_i(4, validators, |header| header.number = 100), None,),),
+			default_accept_into_pool(|validators| (HeaderBuilder::with_number(100).sign_by_set(&validators), None),),
 			Err(Error::UnsignedTooFarInTheFuture),
 		);
 	}
@@ -758,8 +732,9 @@ mod tests {
 		// checks for DoubleVote
 		assert_eq!(
 			default_accept_into_pool(|validators| (
-				custom_block_i(4, validators, |header| header.seal[0] =
-					block_i(3, validators).seal[0].clone()),
+				HeaderBuilder::with_parent_number(3)
+					.step(GENESIS_STEP + 3)
+					.sign_by_set(&validators),
 				None,
 			),),
 			Err(Error::DoubleVote),
@@ -772,21 +747,7 @@ mod tests {
 		// (even if header will be considered invalid/duplicate later, we can use this signature
 		// as a proof of malicious action by this validator)
 		assert_eq!(
-			default_accept_into_pool(|validators| (
-				signed_header(
-					validators,
-					Header {
-						author: validators[1].address().as_fixed_bytes().into(),
-						seal: vec![vec![8].into(), vec![].into()],
-						gas_limit: test_aura_config().min_gas_limit,
-						parent_hash: [42; 32].into(),
-						number: 8,
-						..Default::default()
-					},
-					43
-				),
-				None,
-			)),
+			default_accept_into_pool(|_| (HeaderBuilder::with_number(8).step(8).sign_by(&validator(1)), None,)),
 			Err(Error::NotValidator),
 		);
 	}
@@ -796,7 +757,7 @@ mod tests {
 		let mut hash = None;
 		assert_eq!(
 			default_accept_into_pool(|validators| {
-				let header = block_i(4, &validators);
+				let header = HeaderBuilder::with_parent_number(3).sign_by_set(validators);
 				hash = Some(header.compute_hash());
 				(header, None)
 			}),
@@ -814,32 +775,22 @@ mod tests {
 
 	#[test]
 	fn pool_verifies_header_with_unknown_parent() {
-		let mut hash = None;
+		let mut id = None;
+		let mut parent_id = None;
 		assert_eq!(
 			default_accept_into_pool(|validators| {
-				let header = signed_header(
-					validators,
-					Header {
-						author: validators[2].address().as_fixed_bytes().into(),
-						seal: vec![vec![47].into(), vec![].into()],
-						gas_limit: test_aura_config().min_gas_limit,
-						parent_hash: [42; 32].into(),
-						number: 5,
-						..Default::default()
-					},
-					47,
-				);
-				hash = Some(header.compute_hash());
+				let header = HeaderBuilder::with_number(5)
+					.step(GENESIS_STEP + 5)
+					.sign_by_set(validators);
+				id = Some(header.compute_id());
+				parent_id = header.parent_id();
 				(header, None)
 			}),
 			Ok((
 				// parent tag required
-				vec![(4u64, [42u8; 32]).encode(),],
+				vec![parent_id.unwrap().encode()],
 				// header provides two tags
-				vec![
-					(5u64, validators_addresses(3)[2]).encode(),
-					(5u64, hash.unwrap()).encode(),
-				],
+				vec![(5u64, validator_address(2)).encode(), id.unwrap().encode(),],
 			)),
 		);
 	}
@@ -852,55 +803,36 @@ mod tests {
 				change_validators_set_at(3, validators_addresses(1), None);
 
 				// header is signed using wrong set
-				let header = signed_header(
-					actual_validators,
-					Header {
-						author: actual_validators[2].address().as_fixed_bytes().into(),
-						seal: vec![vec![47].into(), vec![].into()],
-						gas_limit: test_aura_config().min_gas_limit,
-						parent_hash: [42; 32].into(),
-						number: 5,
-						..Default::default()
-					},
-					47,
-				);
+				let header = HeaderBuilder::with_number(5)
+					.step(GENESIS_STEP + 2)
+					.sign_by_set(actual_validators);
 
 				(header, None)
 			}),
 			Err(Error::NotValidator),
 		);
 
-		let mut hash = None;
+		let mut id = None;
+		let mut parent_id = None;
 		assert_eq!(
 			default_accept_into_pool(|actual_validators| {
 				// change finalized set at parent header + signal valid set at parent block
 				change_validators_set_at(3, validators_addresses(10), Some(validators_addresses(3)));
 
 				// header is signed using wrong set
-				let header = signed_header(
-					actual_validators,
-					Header {
-						author: actual_validators[2].address().as_fixed_bytes().into(),
-						seal: vec![vec![47].into(), vec![].into()],
-						gas_limit: test_aura_config().min_gas_limit,
-						parent_hash: [42; 32].into(),
-						number: 5,
-						..Default::default()
-					},
-					47,
-				);
-				hash = Some(header.compute_hash());
+				let header = HeaderBuilder::with_number(5)
+					.step(GENESIS_STEP + 2)
+					.sign_by_set(actual_validators);
+				id = Some(header.compute_id());
+				parent_id = header.parent_id();
 
 				(header, None)
 			}),
 			Ok((
 				// parent tag required
-				vec![(4u64, [42u8; 32]).encode(),],
+				vec![parent_id.unwrap().encode(),],
 				// header provides two tags
-				vec![
-					(5u64, validators_addresses(3)[2]).encode(),
-					(5u64, hash.unwrap()).encode(),
-				],
+				vec![(5u64, validator_address(2)).encode(), id.unwrap().encode(),],
 			)),
 		);
 	}
@@ -909,9 +841,9 @@ mod tests {
 	fn pool_rejects_headers_with_invalid_receipts() {
 		assert_eq!(
 			default_accept_into_pool(|validators| {
-				let header = custom_block_i(4, &validators, |header| {
-					header.log_bloom = (&[0xff; 256]).into();
-				});
+				let header = HeaderBuilder::with_parent_number(3)
+					.log_bloom((&[0xff; 256]).into())
+					.sign_by_set(validators);
 				(header, Some(vec![validators_change_recept(Default::default())]))
 			}),
 			Err(Error::TransactionsReceiptsMismatch),
@@ -923,12 +855,14 @@ mod tests {
 		let mut hash = None;
 		assert_eq!(
 			default_accept_into_pool(|validators| {
-				let header = custom_block_i(4, &validators, |header| {
-					header.log_bloom = (&[0xff; 256]).into();
-					header.receipts_root = "81ce88dc524403b796222046bf3daf543978329b87ffd50228f1d3987031dc45"
-						.parse()
-						.unwrap();
-				});
+				let header = HeaderBuilder::with_parent_number(3)
+					.log_bloom((&[0xff; 256]).into())
+					.receipts_root(
+						"81ce88dc524403b796222046bf3daf543978329b87ffd50228f1d3987031dc45"
+							.parse()
+							.unwrap(),
+					)
+					.sign_by_set(validators);
 				hash = Some(header.compute_hash());
 				(header, Some(vec![validators_change_recept(Default::default())]))
 			}),

bridges/primitives/ethereum-poa/Cargo.toml

@@ -20,9 +20,6 @@ hash-db = { version = "0.15.2", default-features = false }
 triehash = { version = "0.8.2", default-features = false }
 plain_hasher = { version = "0.2.2", default-features = false }
 
-[dev-dependencies]
-hex-literal = "0.2"
-
 # Substrate Based Dependencies
 [dependencies.sp-api]
 version = "2.0.0-rc3"
@@ -48,9 +45,18 @@ default-features = false
 rev = "606c56d2e2f69f68f3947551224be6a3515dff60"
 git = "https://github.com/paritytech/substrate.git"
 
+[dependencies.libsecp256k1]
+optional = true
+version = "0.3.4"
+default-features = false
+features = ["hmac"]
+
+[dev-dependencies]
+hex-literal = "0.2"
+
 [features]
 default = ["std"]
-test-helpers = []
+test-helpers = ["libsecp256k1"]
 std = [
 	"serde/std",
 	"serde-big-array",

bridges/primitives/ethereum-poa/src/lib.rs

@@ -18,8 +18,6 @@
 
 pub use parity_bytes::Bytes;
 pub use primitive_types::{H160, H256, H512, U128, U256};
-
-#[cfg(feature = "test-helpers")]
 pub use rlp::encode as rlp_encode;
 
 use codec::{Decode, Encode};
@@ -49,6 +47,9 @@ pub type RawTransaction = Vec<u8>;
 /// An ethereum address.
 pub type Address = H160;
 
+#[cfg(any(feature = "test-helpers", test))]
+pub mod signatures;
+
 /// Complete header id.
 #[derive(Encode, Decode, Default, RuntimeDebug, PartialEq, Clone, Copy)]
 pub struct HeaderId {
@@ -59,8 +60,8 @@ pub struct HeaderId {
 }
 
 /// An Aura header.
-#[derive(Clone, Encode, Decode, PartialEq, RuntimeDebug)]
-#[cfg_attr(feature = "std", derive(Default, Serialize, Deserialize))]
+#[derive(Clone, Default, Encode, Decode, PartialEq, RuntimeDebug)]
+#[cfg_attr(feature = "std", derive(Serialize, Deserialize))]
 pub struct Header {
 	/// Parent block hash.
 	pub parent_hash: H256,
@@ -457,6 +458,11 @@ pub fn compute_merkle_root<T: AsRef<[u8]>>(items: impl Iterator<Item = T>) -> H2
 	triehash::ordered_trie_root::<Keccak256Hasher, _>(items)
 }
 
+/// Get validator that should author the block at given step.
+pub fn step_validator<T>(header_validators: &[T], header_step: u64) -> &T {
+	&header_validators[(header_step % header_validators.len() as u64) as usize]
+}
+
 sp_api::decl_runtime_apis! {
 	/// API for headers submitters.
 	pub trait EthereumHeadersApi {

bridges/primitives/ethereum-poa/src/signatures.rs

@@ -0,0 +1,66 @@
+// Copyright 2020 Parity Technologies (UK) Ltd.
+// This file is part of Parity Bridges Common.
+
+// Parity Bridges Common is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Parity Bridges Common is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Parity Bridges Common.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+//! Helpers related to signatures.
+//!
+//! Used for testing and benchmarking.
+
+use crate::{public_to_address, rlp_encode, step_validator, Address, Header, H256, H520};
+
+use secp256k1::{Message, PublicKey, SecretKey};
+
+/// Utilities for signing headers.
+pub trait SignHeader {
+	/// Signs header by given author.
+	fn sign_by(self, author: &SecretKey) -> Header;
+	/// Signs header by given authors set.
+	fn sign_by_set(self, authors: &[SecretKey]) -> Header;
+}
+
+impl SignHeader for Header {
+	fn sign_by(mut self, author: &SecretKey) -> Self {
+		self.author = secret_to_address(author);
+
+		let message = self.seal_hash(false).unwrap();
+		let signature = sign(author, message);
+		self.seal[1] = rlp_encode(&signature);
+		self
+	}
+
+	fn sign_by_set(self, authors: &[SecretKey]) -> Self {
+		let step = self.step().unwrap();
+		let author = step_validator(authors, step);
+		self.sign_by(author)
+	}
+}
+
+/// Return author's signature over given message.
+pub fn sign(author: &SecretKey, message: H256) -> H520 {
+	let (signature, recovery_id) = secp256k1::sign(&Message::parse(message.as_fixed_bytes()), author);
+	let mut raw_signature = [0u8; 65];
+	raw_signature[..64].copy_from_slice(&signature.serialize());
+	raw_signature[64] = recovery_id.serialize();
+	raw_signature.into()
+}
+
+/// Returns address corresponding to given secret key.
+pub fn secret_to_address(secret: &SecretKey) -> Address {
+	let public = PublicKey::from_secret_key(secret);
+	let mut raw_public = [0u8; 64];
+	raw_public.copy_from_slice(&public.serialize()[1..]);
+	public_to_address(&raw_public)
+}