feat: add bridger

Author: romanagureev

contracts/bridgers/IBridger.vyi

@@ -0,0 +1,42 @@
+# pragma version ~=0.4.0
+"""
+@title Curve Bridge Adapter
+@license MIT
+@author CurveFi
+@notice Interface mainly used for bridging Curve emissions to L2s and collected fees to Ethereum.
+"""
+
+from ethereum.ercs import IERC20
+
+
+@external
+@payable
+def bridge(_token: IERC20, _to: address, _amount: uint256, _min_amount: uint256=0) -> uint256:
+    """
+    @notice Bridge `_token`
+    @param _token The ERC20 asset to bridge
+    @param _to The receiver on `_chain_id`
+    @param _amount The amount of `_token` to deposit, 2^256-1 for the whole balance
+    @param _min_amount Minimum amount when to bridge
+    @return Bridged amount
+    """
+    ...
+
+
+@view
+@external
+def check(_account: address) -> bool:
+    """
+    @notice Check if `_account` may bridge via `transmit_emissions`
+    @param _account The account to check
+    """
+    ...
+
+
+@view
+@external
+def cost() -> uint256:
+    """
+    @notice Cost in ETH to bridge, not all chains are supported
+    """
+    ...

contracts/bridgers/LzXdaoBridger.vy

@@ -0,0 +1,79 @@
+# @version 0.4.0
+"""
+@title LzXdaoBridger
+@custom:version 0.0.1
+@author Curve.Fi
+@license Copyright (c) Curve.Fi, 2020-2024 - all rights reserved
+@notice Curve Xdao Layer Zero bridge wrapper
+"""
+
+version: public(constant(String[8])) = "0.0.1"
+
+from ethereum.ercs import IERC20
+import IBridger
+
+implements: IBridger
+
+
+interface Bridge:
+    def bridge(_receiver: address, _amount: uint256, _refund: address): payable
+    def quote() -> uint256: view
+
+
+CRV20: constant(address) = 0xD533a949740bb3306d119CC777fa900bA034cd52
+BRIDGE: public(immutable(Bridge))
+
+DESTINATION_CHAIN_ID: public(immutable(uint256))
+
+
+@deploy
+def __init__(_bridge: Bridge, _chain_id: uint256):
+    """
+    @param _bridge Layer Zero Bridge of CRV
+    @param _chain_id Chain ID to bridge to (actual, not LZ)
+    """
+    BRIDGE = _bridge
+    DESTINATION_CHAIN_ID = _chain_id
+
+    assert extcall IERC20(CRV20).approve(BRIDGE.address, max_value(uint256))
+
+
+@external
+@payable
+def bridge(_token: IERC20, _to: address, _amount: uint256, _min_amount: uint256=0) -> uint256:
+    """
+    @notice Bridge `_token` through XDAO Layer Zero
+    @param _token The ERC20 asset to bridge
+    @param _to The receiver on `_chain_id`
+    @param _amount The amount of `_token` to deposit, 2^256-1 for the whole balance
+    @param _min_amount Minimum amount when to bridge
+    @return Bridged amount
+    """
+    amount: uint256 = _amount
+    if amount == max_value(uint256):
+        amount = min(staticcall _token.balanceOf(msg.sender), staticcall _token.allowance(msg.sender, self))
+    assert amount >= _min_amount, "Amount too small"
+
+    assert extcall _token.transferFrom(msg.sender, self, amount)
+
+    extcall BRIDGE.bridge(_to, amount, msg.sender, value=self.balance)
+    return amount
+
+
+@view
+@external
+def cost() -> uint256:
+    """
+    @notice Cost in ETH to bridge
+    """
+    return staticcall BRIDGE.quote()
+
+
+@view
+@external
+def check(_account: address) -> bool:
+    """
+    @notice Check if `_account` is allowed to bridge
+    @param _account The account to check
+    """
+    return True

tests/forked/test_bridgers.py

@@ -159,3 +159,21 @@ def test_polygonzkevm_bridger(alice, crv_token, PolygonzkEVMBridger):
     assert crv_token.balanceOf(bridge) == balance_before + 10**18
     assert "BridgeEvent" in tx.events
     assert tx.events["BridgeEvent"].values()[2:5] == [crv_token, 3, bridger]
+
+
+@pytest.skip(msg="vyper 0.4.0 not supported yet")
+def test_lz_xdao_bridger(alice, bob, crv_token, LzXdaoBridger):
+    bridge = "0xC91113B4Dd89dd20FDEECDAC82477Bc99A840355"
+    bridger = LzXdaoBridger.deploy(bridge, 56, {"from": alice})
+
+    assert bridger.check(alice) is True
+
+    crv_token.approve(bridger, 2 ** 256 - 1, {"from": alice})
+
+    balance_before = crv_token.balanceOf(alice)
+    tx = bridger.bridge(crv_token, bob, 10 ** 18, {"from": alice, "value": bridger.cost()})
+
+    assert crv_token.balanceOf(alice) == balance_before - 10 ** 18
+    assert crv_token.balanceOf(bridger) == 0
+    assert "BridgeSent" in tx.events
+    assert tx.events["BridgeSent"].values() == [bob, 10 ** 18]