withdraw to L1 support and test

.gitignore

@@ -3,6 +3,4 @@ node_modules
 build
 cache
 artifacts
-artifacts-ovm
-cache-ovm
 src/types

contracts/Mocks/MockOmniBridge.sol

@@ -17,4 +17,34 @@ contract MockOmniBridge is IOmniBridge {
   function execute(address _who, bytes calldata _calldata) external returns (bool success, bytes memory result) {
     (success, result) = _who.call(_calldata);
   }
+
+  event OnTokenTransfer(address contr, address from, address receiver, uint256 value, bytes data);
+
+  function onTokenTransfer(
+    address _from,
+    uint256 _value,
+    bytes memory _data
+  ) external returns (bool) {
+    bytes memory data = new bytes(0);
+    address receiver = _from;
+    if (_data.length >= 20) {
+      receiver = bytesToAddress(_data);
+      if (_data.length > 20) {
+        assembly {
+          let size := sub(mload(_data), 20)
+          data := add(_data, 20)
+          mstore(data, size)
+        }
+      }
+    }
+    emit OnTokenTransfer(msg.sender, _from, receiver, _value, data);
+    //bridgeSpecificActionsOnTokenTransfer(msg.sender, _from, receiver, _value, data);
+    return true;
+  }
+
+  function bytesToAddress(bytes memory _bytes) internal pure returns (address addr) {
+    assembly {
+      addr := mload(add(_bytes, 20))
+    }
+  }
 }

contracts/TornadoPool.sol

@@ -16,6 +16,8 @@ pragma experimental ABIEncoderV2;
 import "@openzeppelin/contracts/contracts/token/ERC20/IERC20.sol";
 import "./MerkleTreeWithHistory.sol";
 
+import "hardhat/console.sol";
+
 interface IERC6777 is IERC20 {
   function transferAndCall(
     address,
@@ -47,6 +49,7 @@ contract TornadoPool is MerkleTreeWithHistory, IERC20Receiver {
   IVerifier public immutable verifier16;
   IERC6777 public immutable token;
   address public immutable omniBridge;
+  address public immutable l1Unwrapper;
 
   struct ExtData {
     address recipient;
@@ -55,7 +58,7 @@ contract TornadoPool is MerkleTreeWithHistory, IERC20Receiver {
     uint256 fee;
     bytes encryptedOutput1;
     bytes encryptedOutput2;
-    bool isL1Withdraw;
+    bool isL1Withdrawal;
   }
 
   struct Proof {
@@ -88,12 +91,14 @@ contract TornadoPool is MerkleTreeWithHistory, IERC20Receiver {
     uint32 _levels,
     address _hasher,
     IERC6777 _token,
-    address _omniBridge
+    address _omniBridge,
+    address _l1Unwrapper
   ) MerkleTreeWithHistory(_levels, _hasher) {
     verifier2 = _verifier2;
     verifier16 = _verifier16;
     token = _token;
     omniBridge = _omniBridge;
+    l1Unwrapper = _l1Unwrapper;
   }
 
   function transact(Proof memory _args, ExtData memory _extData) public {
@@ -120,13 +125,12 @@ contract TornadoPool is MerkleTreeWithHistory, IERC20Receiver {
 
     if (_extData.extAmount < 0) {
       require(_extData.recipient != address(0), "Can't withdraw to zero address");
-      if (_extData.isL1Withdraw) {
+      if (_extData.isL1Withdrawal) {
-        token.transferAndCall(omniBridge, uint256(-_extData.extAmount), abi.encode(_extData.recipient));
+        token.transferAndCall(omniBridge, uint256(-_extData.extAmount), abi.encodePacked(l1Unwrapper, _extData.recipient));
       } else {
         token.transfer(_extData.recipient, uint256(-_extData.extAmount));
       }
     }
-
     if (_extData.fee > 0) {
       token.transfer(_extData.relayer, _extData.fee);
     }

src/index.js

@@ -146,7 +146,7 @@ async function transaction({ tornadoPool, ...rest }) {
   const receipt = await tornadoPool.transact(args, extData, {
     gasLimit: 1e6,
   })
-  await receipt.wait()
+  return await receipt.wait()
 }
 
 async function registerAndTransact({ tornadoPool, packedPrivateKeyData, poolAddress, ...rest }) {
@@ -166,4 +166,4 @@ async function registerAndTransact({ tornadoPool, packedPrivateKeyData, poolAddr
   await receipt.wait()
 }
 
-module.exports = { transaction, registerAndTransact }
+module.exports = { transaction, registerAndTransact, prepareTransaction }

test/full.test.js

@@ -5,7 +5,7 @@ const { expect } = require('chai')
 const { utils } = ethers
 
 const Utxo = require('../src/utxo')
-const { transaction, registerAndTransact } = require('../src/index')
+const { transaction, registerAndTransact, prepareTransaction } = require('../src/index')
 const { Keypair } = require('../src/keypair')
 
 const MERKLE_TREE_HEIGHT = 5
@@ -21,7 +21,7 @@ describe('TornadoPool', function () {
 
   async function fixture() {
     require('../scripts/compileHasher')
-    const [sender, gov] = await ethers.getSigners()
+    const [sender, gov, l1Unwrapper] = await ethers.getSigners()
     const verifier2 = await deploy('Verifier2')
     const verifier16 = await deploy('Verifier16')
     const hasher = await deploy('Hasher')
@@ -41,6 +41,7 @@ describe('TornadoPool', function () {
       hasher.address,
       token.address,
       omniBridge.address,
+      l1Unwrapper.address,
     )
     await tornadoPool.initialize()
 
@@ -211,6 +212,54 @@ describe('TornadoPool', function () {
     expect(bobBalance).to.be.equal(bobWithdrawAmount)
   })
 
+  it('should deposit from L1 and withdraw to L1', async function () {
+    const { tornadoPool, token, omniBridge } = await loadFixture(fixture)
+    // console.log('tornadoPool', tornadoPool.interface)
+
+    // Alice deposits into tornado pool
+    const aliceDepositAmount = 1e7
+    const aliceDepositUtxo = new Utxo({ amount: aliceDepositAmount })
+    const { args, extData } = await prepareTransaction({
+      tornadoPool,
+      outputs: [aliceDepositUtxo],
+    })
+    const transactTx = await tornadoPool.populateTransaction.registerAndTransact(
+      { pubKey: [], account: [] },
+      args,
+      extData,
+    )
+    const onTokenBridgedData = '0x' + transactTx.data.slice(10)
+    const onTokenBridgedTx = await tornadoPool.populateTransaction.onTokenBridged(
+      token.address,
+      aliceDepositUtxo.amount,
+      onTokenBridgedData,
+    )
+    // emulating bridge. first it sends tokens and then calls onTokenBridged method
+    await token.transfer(tornadoPool.address, aliceDepositAmount)
+    await omniBridge.execute(tornadoPool.address, onTokenBridgedTx.data)
+
+    // withdraws a part of his funds from the shielded pool
+    const aliceKeypair = new Keypair() // contains private and public keys
+    const aliceWithdrawAmount = 2e6
+    const recipient = '0xDeaD00000000000000000000000000000000BEEf'
+    const aliceChangeUtxo = new Utxo({
+      amount: aliceDepositAmount - aliceWithdrawAmount,
+      keypair: aliceKeypair,
+    })
+    await transaction({
+      tornadoPool,
+      inputs: [aliceDepositUtxo],
+      outputs: [aliceChangeUtxo],
+      recipient: recipient,
+      isL1Withdrawal: true,
+    })
+
+    const recipientBalance = await token.balanceOf(recipient)
+    expect(recipientBalance).to.be.equal(0)
+    const omniBridgeBalance = await token.balanceOf(omniBridge.address)
+    expect(omniBridgeBalance).to.be.equal(aliceWithdrawAmount)
+  })
+
   it('should work with 16 inputs', async function () {
     const { tornadoPool } = await loadFixture(fixture)
     await transaction({ tornadoPool, inputs: [new Utxo(), new Utxo(), new Utxo()] })