Merge pull request #8 from gardenfi/feat/instantRefund

Instant Refund
gardenfi · Jun 7, 2024 · 9264b4c · 9264b4c
2 parents 16eb2a9 + ff1593d
commit 9264b4c
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Showing 2 changed files with 92 additions and 4 deletions.
diff --git a/contracts/htlc/GardenHTLC.sol b/contracts/htlc/GardenHTLC.sol
@@ -35,6 +35,8 @@ contract GardenHTLC is EIP712 {
     bytes32 private constant _INITIATE_TYPEHASH =
         keccak256("Initiate(address redeemer,uint256 expiry,uint256 amount,bytes32 secretHash)");
 
+    bytes32 private constant _REFUND_TYPEHASH = keccak256("Refund(bytes32 orderId)");
+
     event Initiated(bytes32 indexed orderID, bytes32 indexed secretHash, uint256 amount);
     event Redeemed(bytes32 indexed orderID, bytes32 indexed secretHash, bytes secret);
     event Refunded(bytes32 indexed orderID);
@@ -195,4 +197,26 @@ contract GardenHTLC is EIP712 {
 
         token.safeTransferFrom(initiator_, address(this), orders[orderID].amount);
     }
+
+    /**
+     * @notice  Redeemers can let initiator refund the locked assets before expiry block number
+     * @dev     Signers cannot refund the the same order multiple times.
+     *          Funds will be SafeTransferred to the initiator.
+     *
+     * @param orderID       orderID of the htlc order
+     * @param signature     EIP712 signature provided by redeemer for instant refund.
+     */
+    function instantRefund(bytes32 orderID, bytes calldata signature) external {
+        address redeemer = _hashTypedDataV4(keccak256(abi.encode(_REFUND_TYPEHASH, orderID))).recover(signature);
+        Order storage order = orders[orderID];
+
+        require(order.redeemer == redeemer, "HTLC: invalid redeemer signature");
+        require(!order.isFulfilled, "HTLC: order fulfilled");
+
+        order.isFulfilled = true;
+
+        emit Refunded(orderID);
+
+        token.safeTransfer(order.initiator, order.amount);
+    }
 }
diff --git a/test/htlc/gardenHTLC.test.ts b/test/htlc/gardenHTLC.test.ts
@@ -21,7 +21,7 @@ describe("--- HTLC ---", () => {
 		secretHash: BytesLike;
 	};
 
-	const TYPES: Record<string, TypedDataField[]> = {
+	const INITIATE_TYPE: Record<string, TypedDataField[]> = {
 		Initiate: [
 			{ name: "redeemer", type: "address" },
 			{ name: "expiry", type: "uint256" },
@@ -30,6 +30,10 @@ describe("--- HTLC ---", () => {
 		],
 	};
 
+	const REFUND_TYPE: Record<string, TypedDataField[]> = {
+		Refund: [{ name: "orderId", type: "bytes32" }],
+	};
+
 	let owner: HardhatEthersSigner;
 	let alice: HardhatEthersSigner;
 	let bob: HardhatEthersSigner;
@@ -45,12 +49,14 @@ describe("--- HTLC ---", () => {
 	let secret3: BytesLike;
 	let secret4: BytesLike;
 	let secret5: BytesLike;
+	let secret6: BytesLike;
 
 	let orderID1: BytesLike;
 	let orderID2: BytesLike;
 	let orderID3: BytesLike;
 	let orderID4: BytesLike;
 	let orderID5: BytesLike;
+	let orderID6: BytesLike;
 
 	let expiry_: BigNumberish;
 
@@ -74,6 +80,7 @@ describe("--- HTLC ---", () => {
 		secret3 = randomBytes(32);
 		secret4 = randomBytes(32);
 		secret5 = randomBytes(32);
+		secret6 = randomBytes(32);
 	});
 
 	describe("- Pre-Conditions -", () => {
@@ -359,7 +366,7 @@ describe("--- HTLC ---", () => {
 				secretHash: ethers.sha256(secret5),
 			};
 
-			const signature = await bob.signTypedData(DOMAIN, TYPES, initiate);
+			const signature = await bob.signTypedData(DOMAIN, INITIATE_TYPE, initiate);
 
 			await expect(
 				gardenHTLC
@@ -383,7 +390,7 @@ describe("--- HTLC ---", () => {
 				secretHash: ethers.sha256(secret5),
 			};
 
-			const signature = await alice.signTypedData(DOMAIN, TYPES, initiate);
+			const signature = await alice.signTypedData(DOMAIN, INITIATE_TYPE, initiate);
 
 			await expect(
 				gardenHTLC
@@ -415,7 +422,7 @@ describe("--- HTLC ---", () => {
 				)
 			);
 
-			const signature = await alice.signTypedData(DOMAIN, TYPES, initiate);
+			const signature = await alice.signTypedData(DOMAIN, INITIATE_TYPE, initiate);
 
 			await expect(
 				gardenHTLC
@@ -533,4 +540,61 @@ describe("--- HTLC ---", () => {
 			expect(await seed.balanceOf(alice.address)).to.equal(ethers.parseEther("500"));
 		});
 	});
+
+	describe("- HTLC - Instant Refund -", () => {
+		let instantRefund: {
+			orderId: string;
+		};
+		it("Should not able to instant refund a swap with an invalid signature.", async () => {
+			expiry_ = (await ethers.provider.getBlockNumber()) + 7200;
+			const initiate: Initiate = {
+				redeemer: bob.address,
+				expiry: expiry_,
+				amount: ethers.parseEther("100"),
+				secretHash: ethers.sha256(secret6),
+			};
+
+			orderID6 = ethers.sha256(
+				ethers.AbiCoder.defaultAbiCoder().encode(
+					["bytes32", "address"],
+					[initiate.secretHash, alice.address]
+				)
+			);
+			await expect(
+				gardenHTLC
+					.connect(alice)
+					.initiate(
+						initiate.redeemer,
+						initiate.expiry,
+						initiate.amount,
+						initiate.secretHash
+					)
+			)
+				.to.emit(gardenHTLC, "Initiated")
+				.withArgs(orderID6, initiate.secretHash, initiate.amount);
+
+			instantRefund = { orderId: orderID6 };
+
+			const instantRefundSig = await alice.signTypedData(
+				DOMAIN,
+				REFUND_TYPE,
+				instantRefund
+			);
+
+			await expect(
+				gardenHTLC.connect(charlie).instantRefund(orderID6, instantRefundSig)
+			).to.be.revertedWith("HTLC: invalid redeemer signature");
+		});
+		it("Should be able to instant refund a swap with an valid signature.", async () => {
+			const instantRefundSig = await bob.signTypedData(
+				DOMAIN,
+				REFUND_TYPE,
+				instantRefund
+			);
+
+			await expect(gardenHTLC.connect(charlie).instantRefund(orderID6, instantRefundSig))
+				.to.emit(gardenHTLC, "Refunded")
+				.withArgs(orderID6);
+		});
+	});
 });