tests.rs

use asset_test_utils::{ExtBuilder, RuntimeHelper};
use codec::Encode;
use cumulus_primitives_utility::ChargeWeightInFungibles;
use frame_support::{
	assert_noop, assert_ok, sp_io,
	weights::{Weight, WeightToFee as WeightToFeeT},
};
use parachains_common::{AccountId, Balance, StatemintAuraId as AuraId};
use statemint_runtime::xcm_config::{
	AssetFeeAsExistentialDepositMultiplierFeeCharger, DotLocation, TrustBackedAssetsPalletLocation,
};
pub use statemint_runtime::{
	constants::fee::WeightToFee, xcm_config::XcmConfig, Assets, Balances, ExistentialDeposit,
	ReservedDmpWeight, Runtime, SessionKeys, System,
};
use xcm::latest::prelude::*;
use xcm_executor::{
	traits::{Convert, WeightTrader},
	XcmExecutor,
};

pub const ALICE: [u8; 32] = [1u8; 32];

type AssetIdForTrustBackedAssetsConvert =
	assets_common::AssetIdForTrustBackedAssetsConvert<TrustBackedAssetsPalletLocation>;

#[test]
fn test_asset_xcm_trader() {
	ExtBuilder::<Runtime>::default()
		.with_collators(vec![AccountId::from(ALICE)])
		.with_session_keys(vec![(
			AccountId::from(ALICE),
			AccountId::from(ALICE),
			SessionKeys { aura: AuraId::from(sp_core::ed25519::Public::from_raw(ALICE)) },
		)])
		.build()
		.execute_with(|| {
			// We need root origin to create a sufficient asset
			let minimum_asset_balance = 333333333_u128;
			let local_asset_id = 1;
			assert_ok!(Assets::force_create(
				RuntimeHelper::<Runtime>::root_origin(),
				local_asset_id.into(),
				AccountId::from(ALICE).into(),
				true,
				minimum_asset_balance
			));

			// We first mint enough asset for the account to exist for assets
			assert_ok!(Assets::mint(
				RuntimeHelper::<Runtime>::origin_of(AccountId::from(ALICE)),
				local_asset_id.into(),
				AccountId::from(ALICE).into(),
				minimum_asset_balance
			));

			// get asset id as multilocation
			let asset_multilocation =
				AssetIdForTrustBackedAssetsConvert::reverse_ref(local_asset_id).unwrap();

			// Set Alice as block author, who will receive fees
			RuntimeHelper::<Runtime>::run_to_block(2, Some(AccountId::from(ALICE)));

			// We are going to buy 400e9 weight
			// Because of the ED being higher in statemine
			// and not to complicate things, we use a little
			// bit more of weight
			let bought = Weight::from_parts(400_000_000_000u64, 0);

			// Lets calculate amount needed
			let asset_amount_needed =
				AssetFeeAsExistentialDepositMultiplierFeeCharger::charge_weight_in_fungibles(
					local_asset_id,
					bought,
				)
				.expect("failed to compute");

			// Lets pay with: asset_amount_needed + asset_amount_extra
			let asset_amount_extra = 100_u128;
			let asset: MultiAsset =
				(asset_multilocation.clone(), asset_amount_needed + asset_amount_extra).into();

			let mut trader = <XcmConfig as xcm_executor::Config>::Trader::new();

			// Lets buy_weight and make sure buy_weight does not return an error
			match trader.buy_weight(bought, asset.into()) {
				Ok(unused_assets) => {
					// Check whether a correct amount of unused assets is returned
					assert_ok!(unused_assets
						.ensure_contains(&(asset_multilocation, asset_amount_extra).into()));
				},
				Err(e) => assert!(false, "Expected Ok(_). Got {:#?}", e),
			}

			// Drop trader
			drop(trader);

			// Make sure author(Alice) has received the amount
			assert_eq!(
				Assets::balance(local_asset_id, AccountId::from(ALICE)),
				minimum_asset_balance + asset_amount_needed
			);

			// We also need to ensure the total supply increased
			assert_eq!(
				Assets::total_supply(local_asset_id),
				minimum_asset_balance + asset_amount_needed
			);
		});
}

#[test]
fn test_asset_xcm_trader_with_refund() {
	ExtBuilder::<Runtime>::default()
		.with_collators(vec![AccountId::from(ALICE)])
		.with_session_keys(vec![(
			AccountId::from(ALICE),
			AccountId::from(ALICE),
			SessionKeys { aura: AuraId::from(sp_core::ed25519::Public::from_raw(ALICE)) },
		)])
		.build()
		.execute_with(|| {
			// We need root origin to create a sufficient asset
			// We set existential deposit to be identical to the one for Balances first
			assert_ok!(Assets::force_create(
				RuntimeHelper::<Runtime>::root_origin(),
				1.into(),
				AccountId::from(ALICE).into(),
				true,
				ExistentialDeposit::get()
			));

			// We first mint enough asset for the account to exist for assets
			assert_ok!(Assets::mint(
				RuntimeHelper::<Runtime>::origin_of(AccountId::from(ALICE)),
				1.into(),
				AccountId::from(ALICE).into(),
				ExistentialDeposit::get()
			));

			let mut trader = <XcmConfig as xcm_executor::Config>::Trader::new();

			// Set Alice as block author, who will receive fees
			RuntimeHelper::<Runtime>::run_to_block(2, Some(AccountId::from(ALICE)));

			// We are going to buy 400e9 weight
			// Because of the ED being higher in statemine
			// and not to complicate things, we use a little
			// bit more of weight
			let bought = Weight::from_parts(400_000_000_000u64, 0);

			let asset_multilocation = AssetIdForTrustBackedAssetsConvert::reverse_ref(1).unwrap();

			// lets calculate amount needed
			let amount_bought = WeightToFee::weight_to_fee(&bought);

			let asset: MultiAsset = (asset_multilocation.clone(), amount_bought).into();

			// Make sure buy_weight does not return an error
			assert_ok!(trader.buy_weight(bought, asset.clone().into()));

			// Make sure again buy_weight does return an error
			// This assert relies on the fact, that we use `TakeFirstAssetTrader` in `WeightTrader` tuple chain, which cannot be called twice
			assert_noop!(trader.buy_weight(bought, asset.into()), XcmError::TooExpensive);

			// We actually use half of the weight
			let weight_used = bought / 2;

			// Make sure refurnd works.
			let amount_refunded = WeightToFee::weight_to_fee(&(bought - weight_used));

			assert_eq!(
				trader.refund_weight(bought - weight_used),
				Some((asset_multilocation, amount_refunded).into())
			);

			// Drop trader
			drop(trader);

			// We only should have paid for half of the bought weight
			let fees_paid = WeightToFee::weight_to_fee(&weight_used);

			assert_eq!(
				Assets::balance(1, AccountId::from(ALICE)),
				ExistentialDeposit::get() + fees_paid
			);

			// We also need to ensure the total supply increased
			assert_eq!(Assets::total_supply(1), ExistentialDeposit::get() + fees_paid);
		});
}

#[test]
fn test_asset_xcm_trader_refund_not_possible_since_amount_less_than_ed() {
	ExtBuilder::<Runtime>::default()
		.with_collators(vec![AccountId::from(ALICE)])
		.with_session_keys(vec![(
			AccountId::from(ALICE),
			AccountId::from(ALICE),
			SessionKeys { aura: AuraId::from(sp_core::ed25519::Public::from_raw(ALICE)) },
		)])
		.build()
		.execute_with(|| {
			// We need root origin to create a sufficient asset
			// We set existential deposit to be identical to the one for Balances first
			assert_ok!(Assets::force_create(
				RuntimeHelper::<Runtime>::root_origin(),
				1.into(),
				AccountId::from(ALICE).into(),
				true,
				ExistentialDeposit::get()
			));

			let mut trader = <XcmConfig as xcm_executor::Config>::Trader::new();

			// Set Alice as block author, who will receive fees
			RuntimeHelper::<Runtime>::run_to_block(2, Some(AccountId::from(ALICE)));

			// We are going to buy 50e9 weight
			// Because of the ED being higher in statemine
			// and not to complicate things, we use a little
			// bit more of weight
			let bought = Weight::from_parts(50_000_000_000u64, 0);

			let asset_multilocation = AssetIdForTrustBackedAssetsConvert::reverse_ref(1).unwrap();

			let amount_bought = WeightToFee::weight_to_fee(&bought);

			assert!(
				amount_bought < ExistentialDeposit::get(),
				"we are testing what happens when the amount does not exceed ED"
			);

			let asset: MultiAsset = (asset_multilocation.clone(), amount_bought).into();

			// Buy weight should return an error
			assert_noop!(trader.buy_weight(bought, asset.into()), XcmError::TooExpensive);

			// not credited since the ED is higher than this value
			assert_eq!(Assets::balance(1, AccountId::from(ALICE)), 0);

			// We also need to ensure the total supply did not increase
			assert_eq!(Assets::total_supply(1), 0);
		});
}

#[test]
fn test_that_buying_ed_refund_does_not_refund() {
	ExtBuilder::<Runtime>::default()
		.with_collators(vec![AccountId::from(ALICE)])
		.with_session_keys(vec![(
			AccountId::from(ALICE),
			AccountId::from(ALICE),
			SessionKeys { aura: AuraId::from(sp_core::ed25519::Public::from_raw(ALICE)) },
		)])
		.build()
		.execute_with(|| {
			// We need root origin to create a sufficient asset
			// We set existential deposit to be identical to the one for Balances first
			assert_ok!(Assets::force_create(
				RuntimeHelper::<Runtime>::root_origin(),
				1.into(),
				AccountId::from(ALICE).into(),
				true,
				ExistentialDeposit::get()
			));

			let mut trader = <XcmConfig as xcm_executor::Config>::Trader::new();

			// Set Alice as block author, who will receive fees
			RuntimeHelper::<Runtime>::run_to_block(2, Some(AccountId::from(ALICE)));

			// We are gonna buy ED
			let bought = Weight::from_parts(ExistentialDeposit::get().try_into().unwrap(), 0);

			let asset_multilocation = AssetIdForTrustBackedAssetsConvert::reverse_ref(1).unwrap();

			let amount_bought = WeightToFee::weight_to_fee(&bought);

			assert!(
				amount_bought < ExistentialDeposit::get(),
				"we are testing what happens when the amount does not exceed ED"
			);

			// We know we will have to buy at least ED, so lets make sure first it will
			// fail with a payment of less than ED
			let asset: MultiAsset = (asset_multilocation.clone(), amount_bought).into();
			assert_noop!(trader.buy_weight(bought, asset.into()), XcmError::TooExpensive);

			// Now lets buy ED at least
			let asset: MultiAsset = (asset_multilocation.clone(), ExistentialDeposit::get()).into();

			// Buy weight should work
			assert_ok!(trader.buy_weight(bought, asset.into()));

			// Should return None. We have a specific check making sure we dont go below ED for
			// drop payment
			assert_eq!(trader.refund_weight(bought), None);

			// Drop trader
			drop(trader);

			// Make sure author(Alice) has received the amount
			assert_eq!(Assets::balance(1, AccountId::from(ALICE)), ExistentialDeposit::get());

			// We also need to ensure the total supply increased
			assert_eq!(Assets::total_supply(1), ExistentialDeposit::get());
		});
}

#[test]
fn test_asset_xcm_trader_not_possible_for_non_sufficient_assets() {
	ExtBuilder::<Runtime>::default()
		.with_collators(vec![AccountId::from(ALICE)])
		.with_session_keys(vec![(
			AccountId::from(ALICE),
			AccountId::from(ALICE),
			SessionKeys { aura: AuraId::from(sp_core::ed25519::Public::from_raw(ALICE)) },
		)])
		.build()
		.execute_with(|| {
			// Create a non-sufficient asset
			let minimum_asset_balance = 1_000_000_u128;
			assert_ok!(Assets::force_create(
				RuntimeHelper::<Runtime>::root_origin(),
				1.into(),
				AccountId::from(ALICE).into(),
				false,
				minimum_asset_balance
			));

			// We first mint enough asset for the account to exist for assets
			assert_ok!(Assets::mint(
				RuntimeHelper::<Runtime>::origin_of(AccountId::from(ALICE)),
				1.into(),
				AccountId::from(ALICE).into(),
				minimum_asset_balance
			));

			let mut trader = <XcmConfig as xcm_executor::Config>::Trader::new();

			// Set Alice as block author, who will receive fees
			RuntimeHelper::<Runtime>::run_to_block(2, Some(AccountId::from(ALICE)));

			// We are going to buy 400e9 weight
			// Because of the ED being higher in statemine
			// and not to complicate things, we use a little
			// bit more of weight
			let bought = Weight::from_parts(400_000_000_000u64, 0);

			// lets calculate amount needed
			let asset_amount_needed = WeightToFee::weight_to_fee(&bought);

			let asset_multilocation = AssetIdForTrustBackedAssetsConvert::reverse_ref(1).unwrap();

			let asset: MultiAsset = (asset_multilocation, asset_amount_needed).into();

			// Make sure again buy_weight does return an error
			assert_noop!(trader.buy_weight(bought, asset.into()), XcmError::TooExpensive);

			// Drop trader
			drop(trader);

			// Make sure author(Alice) has NOT received the amount
			assert_eq!(Assets::balance(1, AccountId::from(ALICE)), minimum_asset_balance);

			// We also need to ensure the total supply NOT increased
			assert_eq!(Assets::total_supply(1), minimum_asset_balance);
		});
}

#[test]
fn test_assets_balances_api_works() {
	use assets_common::runtime_api::runtime_decl_for_fungibles_api::FungiblesApi;

	ExtBuilder::<Runtime>::default()
		.with_collators(vec![AccountId::from(ALICE)])
		.with_session_keys(vec![(
			AccountId::from(ALICE),
			AccountId::from(ALICE),
			SessionKeys { aura: AuraId::from(sp_core::ed25519::Public::from_raw(ALICE)) },
		)])
		.build()
		.execute_with(|| {
			let local_asset_id = 1;

			// check before
			assert_eq!(Assets::balance(local_asset_id, AccountId::from(ALICE)), 0);
			assert_eq!(Balances::free_balance(AccountId::from(ALICE)), 0);
			assert!(Runtime::query_account_balances(AccountId::from(ALICE)).unwrap().is_empty());

			// Drip some balance
			use frame_support::traits::fungible::Mutate;
			let some_currency = ExistentialDeposit::get();
			Balances::mint_into(&AccountId::from(ALICE), some_currency).unwrap();

			// We need root origin to create a sufficient asset
			let minimum_asset_balance = 3333333_u128;
			assert_ok!(Assets::force_create(
				RuntimeHelper::<Runtime>::root_origin(),
				local_asset_id.into(),
				AccountId::from(ALICE).into(),
				true,
				minimum_asset_balance
			));

			// We first mint enough asset for the account to exist for assets
			assert_ok!(Assets::mint(
				RuntimeHelper::<Runtime>::origin_of(AccountId::from(ALICE)),
				local_asset_id.into(),
				AccountId::from(ALICE).into(),
				minimum_asset_balance
			));

			// check after
			assert_eq!(
				Assets::balance(local_asset_id, AccountId::from(ALICE)),
				minimum_asset_balance
			);
			assert_eq!(Balances::free_balance(AccountId::from(ALICE)), some_currency);

			let result = Runtime::query_account_balances(AccountId::from(ALICE)).unwrap();
			assert_eq!(result.len(), 2);

			// check currency
			assert!(result.iter().any(|asset| asset.eq(
				&assets_common::fungible_conversion::convert_balance::<DotLocation, Balance>(
					some_currency
				)
				.unwrap()
			)));
			// check trusted asset
			assert!(result.iter().any(|asset| asset.eq(&(
				AssetIdForTrustBackedAssetsConvert::reverse_ref(local_asset_id).unwrap(),
				minimum_asset_balance
			)
				.into())));
		});
}

#[test]
fn receive_teleported_asset_works() {
	ExtBuilder::<Runtime>::default()
		.with_collators(vec![AccountId::from(ALICE)])
		.with_session_keys(vec![(
			AccountId::from(ALICE),
			AccountId::from(ALICE),
			SessionKeys { aura: AuraId::from(sp_core::ed25519::Public::from_raw(ALICE)) },
		)])
		.build()
		.execute_with(|| {
			let xcm = Xcm(vec![
				ReceiveTeleportedAsset(MultiAssets::from(vec![MultiAsset {
					id: Concrete(MultiLocation { parents: 1, interior: Here }),
					fun: Fungible(10000000000000),
				}])),
				ClearOrigin,
				BuyExecution {
					fees: MultiAsset {
						id: Concrete(MultiLocation { parents: 1, interior: Here }),
						fun: Fungible(10000000000000),
					},
					weight_limit: Limited(Weight::from_parts(1303531000, 65536)),
				},
				DepositAsset {
					assets: Wild(AllCounted(1)),
					beneficiary: MultiLocation {
						parents: 0,
						interior: X1(AccountId32 {
							network: None,
							id: [
								18, 153, 85, 112, 1, 245, 88, 21, 211, 252, 181, 60, 116, 70, 58,
								203, 12, 246, 209, 77, 70, 57, 179, 64, 152, 44, 96, 135, 127, 56,
								70, 9,
							],
						}),
					},
				},
			]);
			let hash = xcm.using_encoded(sp_io::hashing::blake2_256);

			let weight_limit = ReservedDmpWeight::get();

			let outcome = XcmExecutor::<XcmConfig>::execute_xcm(Parent, xcm, hash, weight_limit);
			assert_eq!(outcome.ensure_complete(), Ok(()));
		})
}