add possibility to depost 0 tokens

contracts/optimism/DepositDataCodec.sol

@@ -27,8 +27,8 @@ contract DepositDataCodec {
  }
 
  DepositData memory depositData;
- depositData.rate = uint256(bytes32(buffer[0:31]));
- depositData.time = uint256(bytes32(buffer[32:63]));
+ depositData.rate = uint256(bytes32(buffer[0:32]));
+ depositData.time = uint256(bytes32(buffer[32:64]));
  depositData.data = buffer[64:];
 
  return depositData;

contracts/optimism/L1ERC20TokenBridge.sol

@@ -68,22 +68,7 @@ contract L1ERC20TokenBridge is
  revert ErrorSenderNotEOA();
  }
 
- DepositData memory depositData;
- depositData.rate = IERC20Wrapable(l1TokenNonRebasable).tokensPerStEth();
- depositData.time = block.timestamp;
- depositData.data = data_;
-
- bytes memory encodedDepositData = encodeDepositData(depositData);
-
- if (isRebasableTokenFlow(l1Token_, l2Token_)) {
- IERC20(l1TokenRebasable).safeTransferFrom(msg.sender, address(this), amount_);
- IERC20(l1TokenRebasable).approve(l1TokenNonRebasable, amount_);
- uint256 wstETHAmount = IERC20Wrapable(l1TokenNonRebasable).wrap(amount_);
- _initiateERC20Deposit(l1TokenRebasable, l2TokenRebasable, msg.sender, msg.sender, wstETHAmount, l2Gas_, encodedDepositData);
- } else if (isNonRebasableTokenFlow(l1Token_, l2Token_)) {
- IERC20(l1TokenNonRebasable).safeTransferFrom(msg.sender, address(this), amount_);
- _initiateERC20Deposit(l1TokenNonRebasable, l2TokenNonRebasable, msg.sender, msg.sender, amount_, l2Gas_, encodedDepositData);
- }
+ _depositERC20To(l1Token_, l2Token_, msg.sender, amount_, l2Gas_, data_);
  }
 
  /// @inheritdoc IL1ERC20Bridge
@@ -101,7 +86,7 @@ contract L1ERC20TokenBridge is
  onlySupportedL1Token(l1Token_)
  onlySupportedL2Token(l2Token_)
  {
- _initiateERC20Deposit(l1Token_, l2Token_, msg.sender, to_, amount_, l2Gas_, data_);
+ _depositERC20To(l1Token_, l2Token_, to_, amount_, l2Gas_, data_);
  }
 
  /// @inheritdoc IL1ERC20Bridge
@@ -123,7 +108,7 @@ contract L1ERC20TokenBridge is
  uint256 stETHAmount = IERC20Wrapable(l1TokenNonRebasable).unwrap(amount_);
  IERC20(l1TokenRebasable).safeTransfer(to_, stETHAmount);
  } else if (isNonRebasableTokenFlow(l1Token_, l2Token_)) {
- IERC20(l1Token_).safeTransfer(to_, amount_);
+ IERC20(l1TokenNonRebasable).safeTransfer(to_, amount_);
  }
 
  emit ERC20WithdrawalFinalized(
@@ -136,6 +121,38 @@ contract L1ERC20TokenBridge is
  );
  }
 
+ function _depositERC20To(
+ address l1Token_,
+ address l2Token_,
+ address to_,
+ uint256 amount_,
+ uint32 l2Gas_,
+ bytes calldata data_
+ ) internal {
+
+ DepositData memory depositData;
+ depositData.rate = IERC20Wrapable(l1TokenNonRebasable).tokensPerStEth();
+ depositData.time = block.timestamp;
+ depositData.data = data_;
+
+ bytes memory encodedDepositData = encodeDepositData(depositData);
+
+ if (amount_ == 0) {
+ _initiateERC20Deposit(l1Token_, l2Token_, msg.sender, to_, amount_, l2Gas_, encodedDepositData);
+ return;
+ }
+
+ if (isRebasableTokenFlow(l1Token_, l2Token_)) {
+ IERC20(l1TokenRebasable).safeTransferFrom(msg.sender, address(this), amount_);
+ IERC20(l1TokenRebasable).approve(l1TokenNonRebasable, amount_);
+ uint256 wstETHAmount = IERC20Wrapable(l1TokenNonRebasable).wrap(amount_);
+ _initiateERC20Deposit(l1TokenRebasable, l2TokenRebasable, msg.sender, to_, wstETHAmount, l2Gas_, encodedDepositData);
+ } else if (isNonRebasableTokenFlow(l1Token_, l2Token_)) {
+ IERC20(l1TokenNonRebasable).safeTransferFrom(msg.sender, address(this), amount_);
+ _initiateERC20Deposit(l1TokenNonRebasable, l2TokenNonRebasable, msg.sender, to_, amount_, l2Gas_, encodedDepositData);
+ }
+ }
+
  /// @dev Performs the logic for deposits by informing the L2 token bridge contract
  /// of the deposit and calling safeTransferFrom to lock the L1 funds.
  /// @param from_ Account to pull the deposit from on L1

contracts/optimism/L2ERC20TokenBridge.sol

@@ -39,8 +39,6 @@ contract L2ERC20TokenBridge is
 
  address public immutable tokensRateOracle;
 
-
-
  /// @param messenger_ L2 messenger address being used for cross-chain communications
  /// @param l1TokenBridge_ Address of the corresponding L1 bridge
  /// @param l1TokenNonRebasable_ Address of the bridged token in the L1 chain
@@ -62,20 +60,12 @@ contract L2ERC20TokenBridge is
 
  /// @inheritdoc IL2ERC20Bridge
  function withdraw(
- address l1Token_,
  address l2Token_,
  uint256 amount_,
  uint32 l1Gas_,
  bytes calldata data_
  ) external whenWithdrawalsEnabled onlySupportedL2Token(l2Token_) {
- if(l2Token_ == l2TokenRebasable) {
- uint256 shares = ERC20Rebasable(l2TokenRebasable).getSharesByTokens(amount_);
- ERC20Rebasable(l2TokenRebasable).burnShares(msg.sender, shares);
- _initiateWithdrawal(l1Token_, l2Token_, msg.sender, msg.sender, shares, l1Gas_, data_);
- } else {
- IERC20Bridged(l2TokenNonRebasable).bridgeBurn(msg.sender, amount_);
- _initiateWithdrawal(l1Token_, l2Token_, msg.sender, msg.sender, amount_, l1Gas_, data_);
- }
+ _withdrawTo(l2Token_, msg.sender, amount_, l1Gas_, data_);
  }
 
  /// @inheritdoc IL2ERC20Bridge
@@ -85,8 +75,28 @@ contract L2ERC20TokenBridge is
  uint256 amount_,
  uint32 l1Gas_,
  bytes calldata data_
- ) external whenWithdrawalsEnabled onlySupportedL2Token(l2Token_) {
- _initiateWithdrawal(l1TokenNonRebasable, l2Token_, msg.sender, to_, amount_, l1Gas_, data_);
+ ) external whenWithdrawalsEnabled onlySupportedL2Token(l2Token_) { 
+ _withdrawTo(l2Token_, to_, amount_, l1Gas_, data_);
+ }
+
+ function _withdrawTo(
+ address l2Token_,
+ address to_,
+ uint256 amount_,
+ uint32 l1Gas_,
+ bytes calldata data_
+ ) internal {
+ if (l2Token_ == l2TokenRebasable) {
+
+ uint256 shares = ERC20Rebasable(l2TokenRebasable).getSharesByTokens(amount_);
+ ERC20Rebasable(l2TokenRebasable).burnShares(msg.sender, shares);
+ _initiateWithdrawal(l1TokenRebasable, l2TokenRebasable, msg.sender, to_, shares, l1Gas_, data_);
+
+ } else if (l2Token_ == l2TokenNonRebasable) {
+
+ IERC20Bridged(l2TokenNonRebasable).bridgeBurn(msg.sender, amount_);
+ _initiateWithdrawal(l2TokenNonRebasable, l2TokenNonRebasable, msg.sender, to_, amount_, l1Gas_, data_);
+ }
  }
 
  /// @inheritdoc IL2ERC20Bridge
@@ -112,6 +122,7 @@ contract L2ERC20TokenBridge is
  } else if (isNonRebasableTokenFlow(l1Token_, l2Token_)) {
  IERC20Bridged(l2TokenNonRebasable).bridgeMint(to_, amount_);
  }
+
  emit DepositFinalized(l1Token_, l2Token_, from_, to_, amount_, depositData.data);
  }
 

contracts/optimism/interfaces/IL2ERC20Bridge.sol

@@ -46,7 +46,6 @@ interface IL2ERC20Bridge {
  /// solely as a convenience for external contracts. Aside from enforcing a maximum
  /// length, these contracts provide no guarantees about its content.
  function withdraw(
- address l1Token_,
  address l2Token_,
  uint256 amount_,
  uint32 l1Gas_,

contracts/stubs/ERC20WrapableStub.sol

@@ -15,13 +15,12 @@ contract ERC20WrapableStub is IERC20Wrapable, ERC20 {
 
  IERC20 public stETH;
  address public bridge;
- uint256 public tokensRate; /// wst/st
+ uint256 public tokensRate;
 
  constructor(IERC20 stETH_, string memory name_, string memory symbol_)
  ERC20(name_, symbol_)
  {
  stETH = stETH_;
- console.log("constructor wrap stETH=",address(stETH));
 
  tokensRate = 2 * 10 **18;
  _mint(msg.sender, 1000000 * 10**18);