Change price conversion function in oracle pallet to work for assets …

…with different decimals (#490)

* Add trait `DecimalsLookup`

* Create default implementation for `DecimalsLookup`

* Change conversion function in Oracle pallet

* Implement `DecimalsLookup` for all configs

* Fix calls to `one()` function

* Create more tests for price conversion

* Fix failing tests in issue pallet

* Fix failing tests in redeem pallet

* Fix failing tests in vault-registry

* Fix vault-registry benchmark

* Implement DecimalsLookup for Pendulum and Amplitude

* Use DecimalsLookup depending on network in metrics calculations

* Small refactoring

* Fix missing import

* Change conversion calculation
#490 (comment)

* Small refactoring

* Test limits of possible conversion amounts

* Use tolerance to other comparison as well
#490 (comment)

clients/vault/Cargo.toml

@@ -25,6 +25,7 @@ async-trait = "0.1.40"
 base64 = { version = '0.13.0', default-features = false, features = ['alloc'] }
 bincode = "1.3.3"
 clap = { version = "3.1", features = ["env"] }
+cfg-if = "1.0.0"
 rand = "0.8.5"
 futures = "0.3.5"
 governor = "0.5.0"

clients/vault/src/lib.rs

@@ -47,3 +47,15 @@ pub const CHAIN_HEIGHT_POLLING_INTERVAL: Duration = Duration::from_millis(500);
 
 /// explicitly yield at most once per second
 pub const YIELD_RATE: Quota = Quota::per_second(nonzero!(1u32));
+
+cfg_if::cfg_if! {
+	if #[cfg(feature = "standalone-metadata")] {
+		pub type DecimalsLookupImpl = primitives::DefaultDecimalsLookup;
+	} else if #[cfg(feature = "parachain-metadata-pendulum")] {
+		pub type DecimalsLookupImpl = primitives::PendulumDecimalsLookup;
+	} else if #[cfg(feature = "parachain-metadata-amplitude")] {
+		pub type DecimalsLookupImpl = primitives::AmplitudeDecimalsLookup;
+	} else if #[cfg(feature = "parachain-metadata-foucoco")] {
+		pub type DecimalsLookupImpl = primitives::AmplitudeDecimalsLookup;
+	}
+}

clients/vault/src/metrics.rs

@@ -2,11 +2,11 @@ use std::{collections::HashMap, convert::TryInto};
 
 use crate::{
 	system::{VaultData, VaultIdManager},
-	Error,
+	DecimalsLookupImpl, Error,
 };
 use async_trait::async_trait;
 use lazy_static::lazy_static;
-use primitives::{stellar, Asset};
+use primitives::{stellar, Asset, DecimalsLookup};
 use runtime::{
 	prometheus::{
 		gather, proto::MetricFamily, Encoder, Gauge, GaugeVec, IntCounter, IntGaugeVec, Opts,
@@ -288,7 +288,7 @@ pub async fn metrics_handler() -> Result<impl Reply, Rejection> {
 }
 
 fn raw_value_as_currency(value: u128, currency: CurrencyId) -> Result<f64, ServiceError<Error>> {
-	let scaling_factor = currency.one() as f64;
+	let scaling_factor = DecimalsLookupImpl::one(currency) as f64;
 	Ok(value as f64 / scaling_factor)
 }
 
@@ -556,7 +556,7 @@ pub async fn publish_expected_stellar_balance<P: VaultRegistryPallet>(
 	if let Ok(v) = parachain_rpc.get_vault(&vault.vault_id).await {
 		let lowerbound = v.issued_tokens.saturating_sub(v.to_be_redeemed_tokens);
 		let upperbound = v.issued_tokens.saturating_add(v.to_be_issued_tokens);
-		let scaling_factor = vault.vault_id.wrapped_currency().one() as f64;
+		let scaling_factor = DecimalsLookupImpl::one(vault.vault_id.wrapped_currency()) as f64;
 
 		vault.metrics.asset_balance.lowerbound.set(lowerbound as f64 / scaling_factor);
 		vault.metrics.asset_balance.upperbound.set(upperbound as f64 / scaling_factor);

clients/vault/tests/vault_integration_tests.rs

@@ -17,10 +17,11 @@ use runtime::{
 };
 use stellar_relay_lib::sdk::PublicKey;
 
-use vault::{service::IssueFilter, Event as CancellationEvent, VaultIdManager};
+use vault::{service::IssueFilter, DecimalsLookupImpl, Event as CancellationEvent, VaultIdManager};
 
 mod helper;
 use helper::*;
+use primitives::DecimalsLookup;
 
 #[tokio::test(flavor = "multi_thread")]
 #[serial]
@@ -54,7 +55,7 @@ async fn test_redeem_succeeds() {
 				VaultIdManager::from_map(vault_provider.clone(), vault_wallet.clone(), vault_ids);
 
 			// We issue 1 (spacewalk-chain) unit
-			let issue_amount = CurrencyId::Native.one();
+			let issue_amount = DecimalsLookupImpl::one(CurrencyId::Native);
 			let vault_collateral = get_required_vault_collateral_for_issue(
 				&vault_provider,
 				issue_amount,
@@ -902,7 +903,7 @@ async fn test_execute_open_requests_succeeds() {
 				VaultIdManager::from_map(vault_provider.clone(), vault_wallet.clone(), vault_ids);
 
 			// We issue 1 (spacewalk-chain) unit
-			let issue_amount = CurrencyId::Native.one();
+			let issue_amount = DecimalsLookupImpl::one(CurrencyId::Native);
 			let vault_collateral = get_required_vault_collateral_for_issue(
 				&vault_provider,
 				issue_amount,

clients/wallet/src/operations.rs

@@ -8,7 +8,7 @@ use primitives::{
 		Asset, ClaimPredicate, Claimant, Memo, Operation, PublicKey, StellarSdkError, StroopAmount,
 		Transaction,
 	},
-	stellar_stroops_to_u128, StellarStroops,
+	stellar_stroops_to_u128, DecimalsLookup, StellarStroops,
 };
 
 pub trait AppendExt<T> {
@@ -98,8 +98,11 @@ pub trait RedeemOperationsExt: HorizonClient {
 
 				// ... and redeeming amount >= 1 XLM, use create account operation
 				if to_be_redeemed_asset == Asset::AssetTypeNative &&
-					to_be_redeemed_amount_u128 >= primitives::CurrencyId::StellarNative.one()
-				{
+					to_be_redeemed_amount_u128 >=
+						// It's okay to use the default here because the Stellar decimals are the same
+						primitives::DefaultDecimalsLookup::one(
+							primitives::CurrencyId::StellarNative,
+						) {
 					create_account_operation(destination_address, to_be_redeemed_amount)
 				}
 				// else use claimable balance

pallets/currency/src/lib.rs

@@ -89,7 +89,8 @@ pub mod pallet {
 			+ Copy
 			+ Default
 			+ Debug
-			+ From<u64>;
+			+ From<u64>
+			+ From<u128>;
 
 		/// Relay chain currency e.g. DOT/KSM
 		#[pallet::constant]

pallets/issue/src/mock.rs

@@ -29,7 +29,7 @@ pub use currency::{
 	Amount,
 };
 pub use primitives::CurrencyId;
-use primitives::{AmountCompatibility, VaultCurrencyPair, VaultId};
+use primitives::{AmountCompatibility, DefaultDecimalsLookup, VaultCurrencyPair, VaultId};
 
 use crate as issue;
 use crate::{Config, Error};
@@ -291,6 +291,7 @@ impl staking::Config for Test {
 impl oracle::Config for Test {
 	type RuntimeEvent = TestEvent;
 	type WeightInfo = oracle::SubstrateWeight<Test>;
+	type DecimalsLookup = DefaultDecimalsLookup;
 	type DataProvider = DiaOracleAdapter<
 		MockDiaOracle,
 		UnsignedFixedPoint,

pallets/issue/src/tests.rs

@@ -447,14 +447,24 @@ fn test_set_issue_period_only_root() {
 #[test]
 fn test_request_issue_fails_exceed_limit_volume_for_issue_request() {
 	run_test(|| {
-		let volume_limit = 1u128;
+		let volume_currency = DEFAULT_COLLATERAL_CURRENCY;
+		let volume_limit = 1_000u128;
 		crate::Pallet::<Test>::_rate_limit_update(
 			std::option::Option::<u128>::Some(volume_limit),
-			DEFAULT_COLLATERAL_CURRENCY,
+			volume_currency,
 			7200u64,
 		);
 
-		let issue_amount = volume_limit + 1;
+		let issue_asset = VAULT.wrapped_currency();
+		// First, convert the volume limit to the issue asset
+		let volume_limit_denoted_in_wrapped_asset =
+			Oracle::convert(&Amount::new(volume_limit, volume_currency), issue_asset)
+				.expect("Price conversion should work");
+
+		// We set the issue amount as the volume limit + 100 (we have to use at least 100 because
+		// the issue_amount might get rounded down during the price conversion between assets with
+		// decimals differing by 2)
+		let issue_amount = volume_limit_denoted_in_wrapped_asset.amount() + 100;
 		let issue_fee = 1;
 		let griefing_collateral = 1;
 		let amount_transferred = issue_amount;
@@ -468,15 +478,22 @@ fn test_request_issue_fails_exceed_limit_volume_for_issue_request() {
 #[test]
 fn test_request_issue_fails_after_execute_issue_exceed_limit_volume_for_issue_request() {
 	run_test(|| {
+		let volume_currency = DEFAULT_COLLATERAL_CURRENCY;
 		let volume_limit = 3u128;
 		crate::Pallet::<Test>::_rate_limit_update(
-			std::option::Option::<u128>::Some(volume_limit),
-			DEFAULT_COLLATERAL_CURRENCY,
+			Option::<u128>::Some(volume_limit),
+			volume_currency,
 			7200u64,
 		);
 
 		let issue_asset = VAULT.wrapped_currency();
-		let issue_amount = volume_limit;
+
+		// We set the issue amount as exactly the volume limit
+		// First, convert the volume limit to the issue asset
+		let volume_limit_denoted_in_wrapped_asset =
+			Oracle::convert(&Amount::new(volume_limit, volume_currency), issue_asset)
+				.expect("Price conversion should work");
+		let issue_amount = volume_limit_denoted_in_wrapped_asset.amount();
 		let issue_fee = 1;
 		let griefing_collateral = 1;
 		let amount_transferred = issue_amount;
@@ -519,15 +536,21 @@ fn test_request_issue_fails_after_execute_issue_exceed_limit_volume_for_issue_re
 #[test]
 fn test_request_issue_success_with_rate_limit() {
 	run_test(|| {
+		let volume_currency = DEFAULT_COLLATERAL_CURRENCY;
 		let volume_limit = 3u128;
 		crate::Pallet::<Test>::_rate_limit_update(
 			std::option::Option::<u128>::Some(volume_limit),
-			DEFAULT_COLLATERAL_CURRENCY,
+			volume_currency,
 			7200u64,
 		);
 
 		let issue_asset = VAULT.wrapped_currency();
-		let issue_amount = volume_limit;
+
+		// We set the issue amount as exactly the volume limit
+		let volume_limit_denoted_in_wrapped_asset =
+			Oracle::convert(&Amount::new(volume_limit, volume_currency), issue_asset)
+				.expect("Price conversion should work");
+		let issue_amount = volume_limit_denoted_in_wrapped_asset.amount();
 		let issue_fee = 1;
 		let griefing_collateral = 1;
 		let amount_transferred = issue_amount;
@@ -562,15 +585,20 @@ fn test_request_issue_success_with_rate_limit() {
 #[test]
 fn test_request_issue_reset_interval_and_succeeds_with_rate_limit() {
 	run_test(|| {
+		let volume_currency = DEFAULT_COLLATERAL_CURRENCY;
 		let volume_limit = 3u128;
 		crate::Pallet::<Test>::_rate_limit_update(
 			std::option::Option::<u128>::Some(volume_limit),
-			DEFAULT_COLLATERAL_CURRENCY,
+			volume_currency,
 			7200u64,
 		);
 
 		let issue_asset = VAULT.wrapped_currency();
-		let issue_amount = volume_limit;
+		let volume_limit_denoted_in_wrapped_asset =
+			Oracle::convert(&Amount::new(volume_limit, volume_currency), issue_asset)
+				.expect("Price conversion should work");
+
+		let issue_amount = volume_limit_denoted_in_wrapped_asset.amount();
 		let issue_fee = 1;
 		let griefing_collateral = 1;
 		let amount_transferred = issue_amount;

pallets/nomination/src/mock.rs

@@ -25,7 +25,7 @@ use oracle::{
 	},
 };
 pub use primitives::CurrencyId;
-use primitives::{VaultCurrencyPair, VaultId};
+use primitives::{DefaultDecimalsLookup, VaultCurrencyPair, VaultId};
 
 use crate as nomination;
 use crate::{Config, Error};
@@ -273,6 +273,7 @@ impl fee::Config for Test {
 impl oracle::Config for Test {
 	type RuntimeEvent = TestEvent;
 	type WeightInfo = oracle::SubstrateWeight<Test>;
+	type DecimalsLookup = DefaultDecimalsLookup;
 	type DataProvider = DiaOracleAdapter<
 		MockDiaOracle,
 		UnsignedFixedPoint,