[WIP] PoV friendly, multi-block Election Provider Multi-Phase pallet

Cargo.toml

@@ -316,6 +316,8 @@ members = [
 	"substrate/frame/conviction-voting",
 	"substrate/frame/core-fellowship",
 	"substrate/frame/democracy",
+	"substrate/frame/election-provider-multi-block",
+	"substrate/frame/election-provider-multi-block/integration-tests",
 	"substrate/frame/election-provider-multi-phase",
 	"substrate/frame/election-provider-multi-phase/test-staking-e2e",
 	"substrate/frame/election-provider-support",

substrate/frame/election-provider-multi-block/Cargo.toml

@@ -0,0 +1,61 @@
+[package]
+name = "pallet-election-provider-multi-block"
+version = "4.0.0-dev"
+authors.workspace = true
+edition.workspace = true
+license = "Apache-2.0"
+homepage = "https://substrate.dev"
+repository.workspace = true
+description = "FRAME pallet election provider multi-block"
+readme = "README.md"
+
+[package.metadata.docs.rs]
+targets = ["x86_64-unknown-linux-gnu"]
+
+[dependencies]
+codec = { package = "parity-scale-codec", version = "3.6.1", default-features = false, features = [
+	"derive",
+] }
+scale-info = { version = "2.10.0", default-features = false, features = [
+	"derive",
+] }
+log = { version = "0.4.17", default-features = false }
+
+frame-support = { version = "4.0.0-dev", default-features = false, path = "../support" }
+frame-system = { version = "4.0.0-dev", default-features = false, path = "../system" }
+
+sp-io = { path = "../../primitives/io", default-features = false}
+sp-std = { path = "../../primitives/std", default-features = false}
+sp-core = { path = "../../primitives/core", default-features = false}
+sp-runtime = { path = "../../primitives/runtime", default-features = false}
+
+frame-election-provider-support = { default-features = false, path = "../election-provider-support" }
+sp-npos-elections = { default-features = false, path = "../../primitives/npos-elections" }
+
+[dev-dependencies]
+sp-tracing = { path = "../../primitives/tracing" }
+pallet-balances = { path = "../balances", default-features = false}
+
+[features]
+default = [ "std" ]
+std = [
+	"codec/std",
+	"scale-info/std",
+	"log/std",
+	"frame-support/std",
+	"frame-system/std",
+	"sp-std/std",
+	"sp-core/std",
+	"sp-io/std",
+	"sp-runtime/std",
+	"frame-election-provider-support/std",
+	"sp-npos-elections/std",
+	"pallet-balances/std",
+]
+try-runtime = [
+	"frame-election-provider-support/try-runtime",
+	"frame-support/try-runtime",
+	"frame-system/try-runtime",
+	"pallet-balances/try-runtime",
+	"sp-runtime/try-runtime",
+]

substrate/frame/election-provider-multi-block/README.md

@@ -0,0 +1 @@
+# Election Provider multi-block

substrate/frame/election-provider-multi-block/integration-tests/Cargo.toml

@@ -0,0 +1,39 @@
+[package]
+name = "pallet-election-tests"
+version = "1.0.0"
+authors.workspace = true
+edition.workspace = true
+license = "Apache-2.0"
+homepage = "https://substrate.io"
+repository.workspace = true
+description = "FRAME election provider multi block pallet tests with staking pallet, bags-list and session pallets"
+publish = false
+
+[package.metadata.docs.rs]
+targets = ["x86_64-unknown-linux-gnu"]
+
+[dev-dependencies]
+parking_lot = "0.12.1"
+codec = { package = "parity-scale-codec", version = "3.6.1", features = ["derive"] }
+scale-info = { version = "2.10.0", features = ["derive"] }
+log = { version = "0.4.17", default-features = false }
+substrate-test-utils = { path = "../../../test-utils" }
+
+sp-runtime = { path = "../../../primitives/runtime" }
+sp-io = { path = "../../../primitives/io" }
+sp-std = { path = "../../../primitives/std" }
+sp-staking = { path = "../../../primitives/staking" }
+sp-core = { path = "../../../primitives/core" }
+sp-npos-elections = { path = "../../../primitives/npos-elections", default-features = false}
+sp-tracing = { path = "../../../primitives/tracing" }
+
+frame-system = { path = "../../system" }
+frame-support = { path = "../../support" }
+frame-election-provider-support = { path = "../../election-provider-support" }
+
+pallet-election-provider-multi-block = { path = ".." }
+pallet-staking = { path = "../../staking" }
+pallet-bags-list = { path = "../../bags-list" }
+pallet-balances = { path = "../../balances" }
+pallet-timestamp = { path = "../../timestamp" }
+pallet-session = { path = "../../session" }

substrate/frame/election-provider-multi-block/integration-tests/src/lib.rs

@@ -0,0 +1,100 @@
+// This file is part of Substrate.
+
+// Copyright (C) Parity Technologies (UK) Ltd.
+// SPDX-License-Identifier: Apache-2.0
+
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// 	http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#![cfg(test)]
+mod mock;
+
+pub(crate) const LOG_TARGET: &str = "integration-tests::epm-staking";
+
+use mock::*;
+
+use frame_election_provider_support::{bounds::ElectionBoundsBuilder, ElectionDataProvider};
+
+use frame_support::assert_ok;
+
+// syntactic sugar for logging.
+#[macro_export]
+macro_rules! log {
+	($level:tt, $patter:expr $(, $values:expr)* $(,)?) => {
+		log::$level!(
+			target: crate::LOG_TARGET,
+			concat!("🛠️  ", $patter)  $(, $values)*
+		)
+	};
+}
+
+fn log_current_time() {
+	log!(
+		info,
+		"block: {:?}, session: {:?}, era: {:?}, EPM phase: {:?} ts: {:?}",
+		System::block_number(),
+		Session::current_index(),
+		Staking::current_era(),
+		ElectionProvider::current_phase(),
+		Timestamp::now()
+	);
+}
+
+#[test]
+fn block_progression_works() {
+	let (mut ext, _pool_state, _) = ExtBuilder::default().build_offchainify();
+	ext.execute_with(|| {})
+}
+
+#[test]
+fn verify_snapshot() {
+	ExtBuilder::default().build_and_execute(|| {
+		assert_eq!(Pages::get(), 3);
+
+		// manually get targets and voters from staking to see the inspect the issue with the
+		// DataProvider.
+		let bounds = ElectionBoundsBuilder::default()
+			.targets_count((TargetSnapshotPerBlock::get() as u32).into())
+			.voters_count((VoterSnapshotPerBlock::get() as u32).into())
+			.build();
+
+		assert_ok!(<Staking as ElectionDataProvider>::electable_targets(bounds.targets, 2));
+		assert_ok!(<Staking as ElectionDataProvider>::electing_voters(bounds.voters, 2));
+	})
+}
+
+mod staking_integration {
+	use super::*;
+
+	#[test]
+	fn call_elect_multi_block() {
+		ExtBuilder::default().build_and_execute(|| {
+			assert_eq!(Pages::get(), 3);
+			assert_eq!(ElectionProvider::current_round(), 0);
+			assert_eq!(Staking::current_era(), Some(0));
+
+			// staking prepares first page of exposures.
+			roll_to(election_prediction() - 3, false);
+
+			// staking prepares second page of exposures.
+			roll_to(election_prediction() - 2, false);
+
+			// staking prepares third page of exposures.
+			roll_to(election_prediction() - 1, false);
+
+			// election successfully, round & era progressed.
+			//assert_eq!(ElectionProvider::current_phase(), Phase::Off);
+			//assert_eq!(ElectionProvider::current_round(), 1);
+			//assert_eq!(Staking::current_era(), Some(1));
+		})
+	}
+}