Escrow for marketplace (#69)

Added ability for the marketplace pallet to use Escrow pallet.
Now Ask orders can accept optional escrow_agent parameter.
If this parameter is present - the seller's funds will be reserved.

pallets/marketplace/Cargo.toml

@@ -30,7 +30,7 @@ sp-std = { workspace = true }
 sp-io = { workspace = true }
 sp-runtime = { workspace = true, default-features = false }
 pallet-nfts = { workspace = true, default-features = false }
-sp-core = { workspace = true, default-features = false}
+sp-core = { workspace = true, default-features = false }
 sp-keystore = { workspace = true, default-features = false }
 pallet-balances = { workspace = true, default-features = false }
 pallet-timestamp = { workspace = true, default-features = false }
@@ -50,9 +50,7 @@ std = [
 	"sp-io/std",
 	"sp-std/std",
 	"pallet-balances/std",
-    "pallet-nfts/std",
-]
-runtime-benchmarks = [
-	"frame-benchmarking/runtime-benchmarks",
+	"pallet-nfts/std",
 ]
+runtime-benchmarks = ["frame-benchmarking/runtime-benchmarks"]
 try-runtime = ["frame-support/try-runtime"]

pallets/marketplace/src/benchmarking.rs

@@ -105,6 +105,7 @@ pub mod benchmarks {
 			expires_at: Timestamp::<T>::get() + T::BenchmarkHelper::timestamp(100000),
 			price,
 			fee: BalanceOf::<T>::from(0u8),
+			escrow_agent: None,
 			signature_data: SignatureData {
 				signature: EthereumSignature::from(Signature::from_raw([0; 65])).into(),
 				nonce: vec![0],
@@ -215,6 +216,7 @@ pub mod benchmarks {
 			expires_at: Timestamp::<T>::get() + T::BenchmarkHelper::timestamp(100000),
 			price,
 			fee: BalanceOf::<T>::from(1u8),
+			escrow_agent: None,
 			signature_data: SignatureData {
 				signature: EthereumSignature::from(Signature::from_raw([0; 65])).into(),
 				nonce: vec![1],

pallets/marketplace/src/lib.rs

@@ -63,7 +63,9 @@ pub mod pallet {
 		/// The currency trait.
 		type Currency: Inspect<Self::AccountId>
 			+ Mutate<Self::AccountId>
-			+ MutateHold<Self::AccountId, Reason = Self::RuntimeHoldReason>;
+			+ MutateHold<Self::AccountId, Reason = <Self as pallet::Config>::RuntimeHoldReason>;
+
+		type Escrow: Escrow<Self::AccountId, BalanceOf<Self>, Self::AccountId>;
 
 		/// Overarching hold reason.
 		type RuntimeHoldReason: From<HoldReason>;
@@ -121,7 +123,7 @@ pub mod pallet {
 		T::CollectionId,
 		Blake2_128Concat,
 		T::ItemId,
-		Ask<T::AccountId, BalanceOf<T>, T::Moment>,
+		Ask<T::AccountId, BalanceOf<T>, T::Moment, T::AccountId>,
 	>;
 
 	#[pallet::storage]
@@ -382,6 +384,7 @@ pub mod pallet {
 							order.item,
 							&order.price,
 							&order.fee,
+							order.escrow_agent,
 						)?;
 					} else {
 						ensure!(
@@ -394,6 +397,7 @@ pub mod pallet {
 							price: order.price,
 							expiration: order.expires_at,
 							fee: order.fee,
+							escrow_agent: order.escrow_agent,
 						};
 
 						Asks::<T>::insert(order.collection, order.item, ask);
@@ -429,6 +433,7 @@ pub mod pallet {
 							order.item,
 							&order.price,
 							&order.fee,
+							order.escrow_agent,
 						)?;
 					} else {
 						ensure!(
@@ -529,7 +534,7 @@ pub mod pallet {
 			collection: &T::CollectionId,
 			item: &T::ItemId,
 			price: &BalanceOf<T>,
-		) -> Option<ExecOrder<T::AccountId, BalanceOf<T>, T::Moment>> {
+		) -> Option<ExecOrder<T::AccountId, BalanceOf<T>, T::Moment, T::AccountId>> {
 			let timestamp = pallet_timestamp::Pallet::<T>::get();
 
 			match order_type {
@@ -554,17 +559,19 @@ pub mod pallet {
 		}
 
 		pub fn execute_order(
-			exec_order: ExecOrder<T::AccountId, BalanceOf<T>, T::Moment>,
+			exec_order: ExecOrder<T::AccountId, BalanceOf<T>, T::Moment, T::AccountId>,
 			who: T::AccountId,
 			collection: T::CollectionId,
 			item: T::ItemId,
 			price: &BalanceOf<T>,
 			fee: &BalanceOf<T>,
+			order_escrow_agent: Option<T::AccountId>,
 		) -> Result<(), DispatchError> {
 			let seller: T::AccountId;
 			let buyer: T::AccountId;
 			let seller_fee: BalanceOf<T>;
 			let buyer_fee: BalanceOf<T>;
+			let escrow_agent: Option<T::AccountId>;
 
 			match exec_order {
 				ExecOrder::Bid(bid) => {
@@ -574,6 +581,7 @@ pub mod pallet {
 					buyer = bid.buyer;
 					seller_fee = *fee;
 					buyer_fee = bid.fee;
+					escrow_agent = order_escrow_agent;
 				},
 				ExecOrder::Ask(ask) => {
 					ensure!(who.clone() != ask.seller.clone(), Error::<T>::BuyerIsSeller);
@@ -582,13 +590,14 @@ pub mod pallet {
 					buyer = who;
 					seller_fee = ask.fee;
 					buyer_fee = *fee;
+					escrow_agent = ask.escrow_agent;
 				},
 			};
 
 			Asks::<T>::remove(collection, item);
 			Bids::<T>::remove((collection, item, *price));
 
-			Self::process_fees(&seller, seller_fee, &buyer, buyer_fee, *price)?;
+			Self::process_fees(&seller, seller_fee, &buyer, buyer_fee, *price, escrow_agent)?;
 
 			pallet_nfts::Pallet::<T>::enable_transfer(&collection, &item)?;
 			<pallet_nfts::Pallet<T> as Transfer<T::AccountId>>::transfer(
@@ -622,6 +631,7 @@ pub mod pallet {
 			buyer: &T::AccountId,
 			buyer_fee: BalanceOf<T>,
 			price: BalanceOf<T>,
+			escrow_agent: Option<T::AccountId>,
 		) -> Result<(), DispatchError> {
 			//Amount to be payed by the buyer
 			let buyer_payment_amount = price.checked_add(&buyer_fee).ok_or(Error::<T>::Overflow)?;
@@ -651,7 +661,19 @@ pub mod pallet {
 				Preserve,
 			)?;
 			//Pay earnings to seller
-			<T as crate::Config>::Currency::transfer(buyer, seller, seller_pay_amount, Preserve)?;
+			match escrow_agent {
+				Some(agent) => {
+					T::Escrow::make_deposit(buyer, seller, seller_pay_amount, &agent)?;
+				},
+				None => {
+					<T as crate::Config>::Currency::transfer(
+						buyer,
+						seller,
+						seller_pay_amount,
+						Preserve,
+					)?;
+				},
+			}
 
 			Ok(())
 		}

pallets/marketplace/src/mock.rs

@@ -1,6 +1,11 @@
 use frame_support::{
-	derive_impl, parameter_types,
-	traits::{AsEnsureOriginWithArg, ConstU128, ConstU32, ConstU64},
+	derive_impl,
+	pallet_prelude::DispatchResult,
+	parameter_types,
+	traits::{
+		fungible::Mutate, AsEnsureOriginWithArg, ConstU128, ConstU32, ConstU64,
+		NamedReservableCurrency,
+	},
 };
 use frame_system as system;
 use sp_core::H256;
@@ -19,6 +24,8 @@ type Signature = EthereumSignature;
 pub type AccountId = <<Signature as Verify>::Signer as IdentifyAccount>::AccountId;
 type Block = frame_system::mocking::MockBlock<Test>;
 
+pub const ESCROW_RESERVE_NAME: &[u8; 8] = b"escrow__";
+
 // Configure a mock runtime to test the pallet.
 frame_support::construct_runtime!(
 	pub enum Test
@@ -97,10 +104,35 @@ impl pallet_nfts::Config for Test {
 	}
 }
 
+pub struct EscrowMock {
+	pub deposit: u128,
+}
+
+impl pallet_marketplace::Escrow<AccountId, u128, AccountId> for EscrowMock {
+	fn make_deposit(
+		depositor: &AccountId,
+		destination: &AccountId,
+		value: u128,
+		_escrow_agent: &AccountId,
+	) -> DispatchResult {
+		Balances::transfer(
+			depositor,
+			destination,
+			value,
+			frame_support::traits::tokens::Preservation::Expendable,
+		)?;
+
+		Balances::reserve_named(ESCROW_RESERVE_NAME, destination, value)?;
+
+		Ok(())
+	}
+}
+
 impl pallet_marketplace::Config for Test {
 	type RuntimeEvent = RuntimeEvent;
 	type RuntimeCall = RuntimeCall;
 	type Currency = Balances;
+	type Escrow = EscrowMock;
 	type RuntimeHoldReason = RuntimeHoldReason;
 	type MinOrderDuration = ConstU64<10>;
 	type NonceStringLimit = ConstU32<50>;
@@ -114,7 +146,7 @@ impl pallet_marketplace::Config for Test {
 
 impl pallet_balances::Config for Test {
 	type MaxLocks = ();
-	type MaxReserves = ();
+	type MaxReserves = ConstU32<2>;
 	type ReserveIdentifier = [u8; 8];
 	type Balance = u128;
 	type DustRemoval = ();