Merge pull request #268 from UniqueNetwork/hotfix/inflation_year_fix

Hotfix/inflation year fix

Author: kozyrevdev

node/cli/src/chain_spec.rs

@@ -220,6 +220,7 @@ fn testnet_genesis(
 		sudo: SudoConfig { key: root_key },
 		vesting: VestingConfig { vesting: vec![] },
 		parachain_info: unique_runtime::ParachainInfoConfig { parachain_id: id },
+		parachain_system: Default::default(),
 		aura: unique_runtime::AuraConfig {
 			authorities: initial_authorities,
 		},

pallets/inflation/src/lib.rs

@@ -75,6 +75,10 @@ pub mod pallet {
 	pub type NextRecalculationBlock<T: Config> =
 		StorageValue<Value = T::BlockNumber, QueryKind = ValueQuery>;
 
+	/// Relay block when inflation has started
+	#[pallet::storage]
+	pub type StartBlock<T: Config> = StorageValue<Value = T::BlockNumber, QueryKind = ValueQuery>;
+
 	#[pallet::hooks]
 	impl<T: Config> Hooks<BlockNumberFor<T>> for Pallet<T> {
 		fn on_initialize(_: T::BlockNumber) -> Weight
@@ -145,8 +149,10 @@ pub mod pallet {
 			ensure_root(origin)?;
 
 			// Start inflation if it has not been yet initialized
-			let next_inflation: T::BlockNumber = <NextInflationBlock<T>>::get();
-			if next_inflation == 0u32.into() {
+			if <StartBlock<T>>::get() == 0u32.into() {
+				// Set inflation global start block
+				<StartBlock<T>>::set(inflation_start_relay_block);
+
 				// Recalculate inflation. This can be backdated and will catch up.
 				Self::recalculate_inflation(inflation_start_relay_block);
 				let block_interval: u32 = T::InflationBlockInterval::get().try_into().unwrap_or(0);
@@ -166,9 +172,10 @@ pub mod pallet {
 
 impl<T: Config> Pallet<T> {
 	pub fn recalculate_inflation(recalculation_block: T::BlockNumber) {
-		let current_year: u32 = (recalculation_block / T::BlockNumber::from(YEAR))
-			.try_into()
-			.unwrap_or(0);
+		let current_year: u32 = ((recalculation_block - <StartBlock<T>>::get())
+			/ T::BlockNumber::from(YEAR))
+		.try_into()
+		.unwrap_or(0);
 		let block_interval: u32 = T::InflationBlockInterval::get().try_into().unwrap_or(0);
 
 		let one_percent = Perbill::from_percent(1);

pallets/inflation/src/tests.rs

@@ -230,6 +230,45 @@ fn inflation_in_1_year() {
 	});
 }
 
+#[test]
+fn inflation_start_large_kusama_block() {
+	new_test_ext().execute_with(|| {
+		// Total issuance = 1_000_000_000
+		let initial_issuance: u64 = 1_000_000_000;
+		let start_block: u64 = 10457457;
+		let _ = <Balances as Currency<_>>::deposit_creating(&1234, initial_issuance);
+		assert_eq!(Balances::free_balance(1234), initial_issuance);
+		MockBlockNumberProvider::set(start_block);
+
+		// Start inflation as sudo
+		assert_ok!(Inflation::start_inflation(
+			RawOrigin::Root.into(),
+			start_block
+		));
+
+		// Go through all the block inflations for year 1,
+		// total issuance will be updated accordingly
+		// Inflation is set to start in block 1, so first iteration is block 101
+		for block in (101..YEAR).step_by(100) {
+			MockBlockNumberProvider::set(start_block + block);
+			Inflation::on_initialize(0);
+		}
+		assert_eq!(
+			initial_issuance + (FIRST_YEAR_BLOCK_INFLATION * (YEAR / 100)),
+			<Balances as Currency<_>>::total_issuance()
+		);
+
+		MockBlockNumberProvider::set(start_block + YEAR + 1);
+		Inflation::on_initialize(0);
+		let block_inflation_year_2 = block_inflation!();
+		// Expected 100-block inflation for year 2: 100 * 9.33% * initial issuance * 110% / YEAR == 1951
+		let expecter_year_2_inflation: u64 = (initial_issuance
+			+ FIRST_YEAR_BLOCK_INFLATION * YEAR / 100)
+			* 933 * 100 / (10000 * YEAR);
+		assert_eq!(block_inflation_year_2 / 10, expecter_year_2_inflation / 10); // divide by 10 for approx. equality
+	});
+}
+
 #[test]
 fn inflation_after_year_10_is_flat() {
 	new_test_ext().execute_with(|| {