Initial implementation of Bitcoin depositor (tBTC Depositor)

core/.eslintrc

@@ -12,11 +12,12 @@
           "test/**"
         ]
       }
-    ]
+    ],
+    "@typescript-eslint/no-use-before-define": "off"
   },
   "overrides": [
     {
-      "files": ["deploy/*.ts"],
+      "files": ["deploy/**/*.ts", "test/**/*.ts"],
       "rules": {
         "@typescript-eslint/unbound-method": "off"
       }

core/contracts/Dispatcher.sol

@@ -1,7 +1,7 @@
 // SPDX-License-Identifier: GPL-3.0-only
 pragma solidity ^0.8.21;
 
-import "@openzeppelin/contracts/access/Ownable.sol";
+import "@openzeppelin/contracts/access/Ownable2Step.sol";
 import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
 import "@openzeppelin/contracts/interfaces/IERC4626.sol";
 import "./Router.sol";
@@ -11,7 +11,7 @@ import "./stBTC.sol";
 /// @notice Dispatcher is a contract that routes tBTC from stBTC to
 ///         yield vaults and back. Vaults supply yield strategies with tBTC that
 ///         generate yield for Bitcoin holders.
-contract Dispatcher is Router, Ownable {
+contract Dispatcher is Router, Ownable2Step {
     using SafeERC20 for IERC20;
 
     /// Struct holds information about a vault.

core/contracts/stBTC.sol

@@ -3,7 +3,7 @@ pragma solidity ^0.8.21;
 
 import "@openzeppelin/contracts/token/ERC20/extensions/ERC4626.sol";
 import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
-import "@openzeppelin/contracts/access/Ownable.sol";
+import "@openzeppelin/contracts/access/Ownable2Step.sol";
 import "./Dispatcher.sol";
 
 /// @title stBTC
@@ -17,7 +17,7 @@ import "./Dispatcher.sol";
 ///      of yield-bearing vaults. This contract facilitates the minting and
 ///      burning of shares (stBTC), which are represented as standard ERC20
 ///      tokens, providing a seamless exchange with tBTC tokens.
-contract stBTC is ERC4626, Ownable {
+contract stBTC is ERC4626, Ownable2Step {
     using SafeERC20 for IERC20;
 
     /// Dispatcher contract that routes tBTC from stBTC to a given vault and back.
@@ -26,8 +26,13 @@ contract stBTC is ERC4626, Ownable {
     /// Address of the treasury wallet, where fees should be transferred to.
     address public treasury;
 
-    /// Minimum amount for a single deposit operation.
+    /// Minimum amount for a single deposit operation. The value should be set
+    /// low enough so the deposits routed through Bitcoin Depositor contract won't
+    /// be rejected. It means that minimumDepositAmount should be lower than
+    /// tBTC protocol's depositDustThreshold reduced by all the minting fees taken
+    /// before depositing in the Acre contract.
     uint256 public minimumDepositAmount;
+
     /// Maximum total amount of tBTC token held by Acre protocol.
     uint256 public maximumTotalAssets;
 

core/contracts/test/AcreBitcoinDepositor.t.sol

@@ -0,0 +1,22 @@
+// SPDX-License-Identifier: GPL-3.0-only
+pragma solidity ^0.8.21;
+
+import {AcreBitcoinDepositor} from "../AcreBitcoinDepositor.sol";
+
+/// @dev A test contract to expose internal function from  AcreBitcoinDepositor contract.
+///      This solution follows Foundry recommendation:
+///      https://book.getfoundry.sh/tutorials/best-practices#internal-functions
+contract AcreBitcoinDepositorHarness is AcreBitcoinDepositor {
+    constructor(
+        address bridge,
+        address tbtcVault,
+        address tbtcToken,
+        address stbtc
+    ) AcreBitcoinDepositor(bridge, tbtcVault, tbtcToken, stbtc) {}
+
+    function exposed_finalizeBridging(
+        uint256 depositKey
+    ) external returns (uint256 amountToStake, address staker) {
+        return finalizeBridging(depositKey);
+    }
+}

core/contracts/test/MockTbtcBridge.sol

@@ -0,0 +1,57 @@
+// SPDX-License-Identifier: GPL-3.0-only
+pragma solidity ^0.8.21;
+
+import {MockBridge, MockTBTCVault} from "@keep-network/tbtc-v2/contracts/test/TestTBTCDepositor.sol";
+import {IBridge} from "@keep-network/tbtc-v2/contracts/integrator/IBridge.sol";
+import {IBridgeTypes} from "@keep-network/tbtc-v2/contracts/integrator/IBridge.sol";
+
+import {TestERC20} from "./TestERC20.sol";
+
+contract BridgeStub is MockBridge {}
+
+contract TBTCVaultStub is MockTBTCVault {
+    TestERC20 public immutable tbtc;
+    IBridge public immutable bridge;
+
+    /// @notice Multiplier to convert satoshi to TBTC token units.
+    uint256 public constant SATOSHI_MULTIPLIER = 10 ** 10;
+
+    constructor(TestERC20 _tbtc, IBridge _bridge) {
+        tbtc = _tbtc;
+        bridge = _bridge;
+    }
+
+    function finalizeOptimisticMintingRequest(
+        uint256 depositKey
+    ) public override {
+        IBridgeTypes.DepositRequest memory deposit = bridge.deposits(
+            depositKey
+        );
+
+        uint256 amountSubTreasury = (deposit.amount - deposit.treasuryFee) *
+            SATOSHI_MULTIPLIER;
+
+        uint256 omFee = optimisticMintingFeeDivisor > 0
+            ? (amountSubTreasury / optimisticMintingFeeDivisor)
+            : 0;
+
+        // The deposit transaction max fee is in the 1e8 satoshi precision.
+        // We need to convert them to the 1e18 TBTC precision.
+        // slither-disable-next-line unused-return
+        (, , uint64 depositTxMaxFee, ) = bridge.depositParameters();
+        uint256 txMaxFee = depositTxMaxFee * SATOSHI_MULTIPLIER;
+
+        uint256 amountToMint = amountSubTreasury - omFee - txMaxFee;
+
+        finalizeOptimisticMintingRequestWithAmount(depositKey, amountToMint);
+    }
+
+    function finalizeOptimisticMintingRequestWithAmount(
+        uint256 depositKey,
+        uint256 amountToMint
+    ) public {
+        MockTBTCVault.finalizeOptimisticMintingRequest(depositKey);
+
+        tbtc.mint(bridge.deposits(depositKey).depositor, amountToMint);
+    }
+}

core/contracts/test/TestERC20.sol

@@ -4,7 +4,7 @@ pragma solidity ^0.8.21;
 import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
 
 contract TestERC20 is ERC20 {
-    constructor() ERC20("Test Token", "TEST") {}
+    constructor(string memory name, string memory symbol) ERC20(name, symbol) {}
 
     function mint(address account, uint256 value) external {
         _mint(account, value);

core/deploy/00_resolve_tbtc_bridge.ts

@@ -0,0 +1,34 @@
+import type { DeployFunction } from "hardhat-deploy/types"
+import type {
+  HardhatNetworkConfig,
+  HardhatRuntimeEnvironment,
+} from "hardhat/types"
+import { isNonZeroAddress } from "../helpers/address"
+
+const func: DeployFunction = async (hre: HardhatRuntimeEnvironment) => {
+  const { getNamedAccounts, deployments } = hre
+  const { log } = deployments
+  const { deployer } = await getNamedAccounts()
+
+  const bridge = await deployments.getOrNull("Bridge")
+
+  if (bridge && isNonZeroAddress(bridge.address)) {
+    log(`using Bridge contract at ${bridge.address}`)
+  } else if ((hre.network.config as HardhatNetworkConfig)?.forking?.enabled) {
+    throw new Error("deployed Bridge contract not found")
+  } else {
+    log("deploying Bridge contract stub")
+
+    await deployments.deploy("Bridge", {
+      contract: "BridgeStub",
+      args: [],
+      from: deployer,
+      log: true,
+      waitConfirmations: 1,
+    })
+  }
+}
+
+export default func
+
+func.tags = ["TBTC", "Bridge"]

core/deploy/00_resolve_tbtc.ts → core/deploy/00_resolve_tbtc_token.ts

@@ -1,5 +1,8 @@
-import type { HardhatRuntimeEnvironment } from "hardhat/types"
 import type { DeployFunction } from "hardhat-deploy/types"
+import type {
+  HardhatNetworkConfig,
+  HardhatRuntimeEnvironment,
+} from "hardhat/types"
 import { isNonZeroAddress } from "../helpers/address"
 
 const func: DeployFunction = async (hre: HardhatRuntimeEnvironment) => {
@@ -11,13 +14,17 @@ const func: DeployFunction = async (hre: HardhatRuntimeEnvironment) => {
 
   if (tbtc && isNonZeroAddress(tbtc.address)) {
     log(`using TBTC contract at ${tbtc.address}`)
-  } else if (!hre.network.tags.allowStubs) {
+  } else if (
+    !hre.network.tags.allowStubs ||
+    (hre.network.config as HardhatNetworkConfig)?.forking?.enabled
+  ) {
     throw new Error("deployed TBTC contract not found")
   } else {
     log("deploying TBTC contract stub")
 
     await deployments.deploy("TBTC", {
       contract: "TestERC20",
+      args: ["Test tBTC", "TestTBTC"],
       from: deployer,
       log: true,
       waitConfirmations: 1,
@@ -27,4 +34,4 @@ const func: DeployFunction = async (hre: HardhatRuntimeEnvironment) => {
 
 export default func
 
-func.tags = ["TBTC"]
+func.tags = ["TBTC", "TBTCToken"]

core/deploy/00_resolve_tbtc_vault.ts

@@ -0,0 +1,41 @@
+import type { DeployFunction } from "hardhat-deploy/types"
+import type {
+  HardhatNetworkConfig,
+  HardhatRuntimeEnvironment,
+} from "hardhat/types"
+import { isNonZeroAddress } from "../helpers/address"
+
+const func: DeployFunction = async (hre: HardhatRuntimeEnvironment) => {
+  const { getNamedAccounts, deployments } = hre
+  const { log } = deployments
+  const { deployer } = await getNamedAccounts()
+
+  const tbtcVault = await deployments.getOrNull("TBTCVault")
+
+  if (tbtcVault && isNonZeroAddress(tbtcVault.address)) {
+    log(`using TBTCVault contract at ${tbtcVault.address}`)
+  } else if (
+    !hre.network.tags.allowStubs ||
+    (hre.network.config as HardhatNetworkConfig)?.forking?.enabled
+  ) {
+    throw new Error("deployed TBTCVault contract not found")
+  } else {
+    log("deploying TBTCVault contract stub")
+
+    const tbtc = await deployments.get("TBTC")
+    const bridge = await deployments.get("Bridge")
+
+    await deployments.deploy("TBTCVault", {
+      contract: "TBTCVaultStub",
+      args: [tbtc.address, bridge.address],
+      from: deployer,
+      log: true,
+      waitConfirmations: 1,
+    })
+  }
+}
+
+export default func
+
+func.tags = ["TBTC", "TBTCVault"]
+func.dependencies = ["TBTCToken", "Bridge"]

core/deploy/02_deploy_dispatcher.ts

@@ -9,15 +9,15 @@ const func: DeployFunction = async (hre: HardhatRuntimeEnvironment) => {
   const tbtc = await deployments.get("TBTC")
   const stbtc = await deployments.get("stBTC")
 
-  await deployments.deploy("Dispatcher", {
+  const dispatcher = await deployments.deploy("Dispatcher", {
     from: deployer,
     args: [stbtc.address, tbtc.address],
     log: true,
     waitConfirmations: waitConfirmationsNumber(hre),
   })
 
   if (hre.network.tags.etherscan) {
-    await helpers.etherscan.verify(stbtc)
+    await helpers.etherscan.verify(dispatcher)
   }
 
   // TODO: Add Tenderly verification

core/deploy/03_deploy_acre_bitcoin_depositor.ts

@@ -0,0 +1,34 @@
+import type { DeployFunction } from "hardhat-deploy/types"
+import type { HardhatRuntimeEnvironment } from "hardhat/types"
+
+const func: DeployFunction = async (hre: HardhatRuntimeEnvironment) => {
+  const { getNamedAccounts, deployments, helpers } = hre
+  const { deployer } = await getNamedAccounts()
+
+  const bridge = await deployments.get("Bridge")
+  const tbtcVault = await deployments.get("TBTCVault")
+  const tbtc = await deployments.get("TBTC")
+  const stbtc = await deployments.get("stBTC")
+
+  const depositor = await deployments.deploy("AcreBitcoinDepositor", {
+    contract:
+      process.env.HARDHAT_TEST === "true"
+        ? "AcreBitcoinDepositorHarness"
+        : "AcreBitcoinDepositor",
+    from: deployer,
+    args: [bridge.address, tbtcVault.address, tbtc.address, stbtc.address],
+    log: true,
+    waitConfirmations: 1,
+  })
+
+  if (hre.network.tags.etherscan) {
+    await helpers.etherscan.verify(depositor)
+  }
+
+  // TODO: Add Tenderly verification
+}
+
+export default func
+
+func.tags = ["AcreBitcoinDepositor"]
+func.dependencies = ["TBTC", "stBTC"]

core/deploy/21_transfer_ownership_stbtc.ts

@@ -14,8 +14,17 @@ const func: DeployFunction = async (hre: HardhatRuntimeEnvironment) => {
     "transferOwnership",
     governance,
   )
+
+  if (hre.network.name !== "mainnet") {
+    await deployments.execute(
+      "stBTC",
+      { from: governance, log: true, waitConfirmations: 1 },
+      "acceptOwnership",
+    )
+  }
 }
 
 export default func
 
 func.tags = ["TransferOwnershipStBTC"]
+func.dependencies = ["stBTC"]

core/deploy/22_transfer_ownership_dispatcher.ts

@@ -14,6 +14,14 @@ const func: DeployFunction = async (hre: HardhatRuntimeEnvironment) => {
     "transferOwnership",
     governance,
   )
+
+  if (hre.network.name !== "mainnet") {
+    await deployments.execute(
+      "Dispatcher",
+      { from: governance, log: true, waitConfirmations: 1 },
+      "acceptOwnership",
+    )
+  }
 }
 
 export default func