Merge pull request #65 from morpho-org/feat/wsteth-oracle

wstETH/ETH oracle using exchange rate only

src/ChainlinkOracle.sol → src/morpho-chainlink-v1/ChainlinkOracle.sol

@@ -2,12 +2,12 @@
 pragma solidity 0.8.21;
 
 import {IChainlinkOracle} from "./interfaces/IChainlinkOracle.sol";
-import {IOracle} from "../lib/morpho-blue/src/interfaces/IOracle.sol";
+import {IOracle} from "../../lib/morpho-blue/src/interfaces/IOracle.sol";
 
 import {AggregatorV3Interface, ChainlinkDataFeedLib} from "./libraries/ChainlinkDataFeedLib.sol";
 import {IERC4626, VaultLib} from "./libraries/VaultLib.sol";
 import {ErrorsLib} from "./libraries/ErrorsLib.sol";
-import {Math} from "../lib/openzeppelin-contracts/contracts/utils/math/Math.sol";
+import {Math} from "../../lib/openzeppelin-contracts/contracts/utils/math/Math.sol";
 
 /// @title ChainlinkOracle
 /// @author Morpho Labs

src/interfaces/IChainlinkOracle.sol → src/morpho-chainlink-v1/interfaces/IChainlinkOracle.sol

@@ -3,7 +3,7 @@ pragma solidity >=0.5.0;
 
 import {IERC4626} from "./IERC4626.sol";
 import {AggregatorV3Interface} from "./AggregatorV3Interface.sol";
-import {IOracle} from "../../lib/morpho-blue/src/interfaces/IOracle.sol";
+import {IOracle} from "../../../lib/morpho-blue/src/interfaces/IOracle.sol";
 
 /// @title IChainlinkOracle
 /// @author Morpho Labs

src/wsteth-exchange-rate-adapter/WstEthStEthExchangeRateChainlinkAdapter.sol

@@ -0,0 +1,30 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+pragma solidity 0.8.21;
+
+import {IStEth} from "./interfaces/IStEth.sol";
+import {MinimalAggregatorV3Interface} from "./interfaces/MinimalAggregatorV3Interface.sol";
+
+/// @title WstEthStEthExchangeRateChainlinkAdapter
+/// @author Morpho Labs
+/// @custom:contact [email protected]
+/// @notice wstETH/stETH exchange rate price feed.
+/// @dev This contract should only be deployed on Ethereum and used as a price feed for Morpho oracles.
+contract WstEthStEthExchangeRateChainlinkAdapter is MinimalAggregatorV3Interface {
+    /// @inheritdoc MinimalAggregatorV3Interface
+    // @dev The calculated price has 18 decimals precision, whatever the value of `decimals`.
+    uint8 public constant decimals = 18;
+
+    /// @notice The description of the price feed.
+    string public constant description = "wstETH/stETH exchange rate";
+
+    /// @notice The address of stETH on Ethereum.
+    IStEth public constant ST_ETH = IStEth(0xae7ab96520DE3A18E5e111B5EaAb095312D7fE84);
+
+    /// @inheritdoc MinimalAggregatorV3Interface
+    /// @dev Returns zero for roundId, startedAt, updatedAt and answeredInRound.
+    /// @dev Silently overflows if `getPooledEthByShares`'s return value is greater than `type(int256).max`.
+    function latestRoundData() external view returns (uint80, int256, uint256, uint256, uint80) {
+        // It is assumed that `getPooledEthByShares` returns a price with 18 decimals precision.
+        return (0, int256(ST_ETH.getPooledEthByShares(1 ether)), 0, 0, 0);
+    }
+}

src/wsteth-exchange-rate-adapter/interfaces/IStEth.sol

@@ -0,0 +1,6 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+pragma solidity >=0.5.0;
+
+interface IStEth {
+    function getPooledEthByShares(uint256) external view returns (uint256);
+}

src/wsteth-exchange-rate-adapter/interfaces/MinimalAggregatorV3Interface.sol

@@ -0,0 +1,17 @@
+// SPDX-License-Identifier: MIT
+pragma solidity >=0.5.0;
+
+/// @dev Inspired by
+/// https://github.com/smartcontractkit/chainlink/blob/master/contracts/src/v0.8/shared/interfaces/AggregatorV3Interface.sol
+/// @dev This is the minimal feed interface required by `MorphoChainlinkOracleV2`.
+interface MinimalAggregatorV3Interface {
+    /// @notice Returns the precision of the feed.
+    function decimals() external view returns (uint8);
+
+    /// @notice Returns Chainlink's `latestRoundData` return values.
+    /// @notice Only the `answer` field is used by `MorphoChainlinkOracleV2`.
+    function latestRoundData()
+        external
+        view
+        returns (uint80 roundId, int256 answer, uint256 startedAt, uint256 updatedAt, uint80 answeredInRound);
+}

test/ChainlinkOracleTest.sol

@@ -2,30 +2,9 @@
 pragma solidity ^0.8.0;
 
 import "../lib/forge-std/src/Test.sol";
-import "../src/ChainlinkOracle.sol";
-import "../src/libraries/ErrorsLib.sol";
+import "../src/morpho-chainlink-v1/ChainlinkOracle.sol";
 import "./mocks/ChainlinkAggregatorMock.sol";
-
-AggregatorV3Interface constant feedZero = AggregatorV3Interface(address(0));
-// 8 decimals of precision
-AggregatorV3Interface constant btcUsdFeed = AggregatorV3Interface(0xF4030086522a5bEEa4988F8cA5B36dbC97BeE88c);
-// 8 decimals of precision
-AggregatorV3Interface constant usdcUsdFeed = AggregatorV3Interface(0x8fFfFfd4AfB6115b954Bd326cbe7B4BA576818f6);
-// 18 decimals of precision
-AggregatorV3Interface constant btcEthFeed = AggregatorV3Interface(0xdeb288F737066589598e9214E782fa5A8eD689e8);
-// 8 decimals of precision
-AggregatorV3Interface constant wBtcBtcFeed = AggregatorV3Interface(0xfdFD9C85aD200c506Cf9e21F1FD8dd01932FBB23);
-// 18 decimals of precision
-AggregatorV3Interface constant stEthEthFeed = AggregatorV3Interface(0x86392dC19c0b719886221c78AB11eb8Cf5c52812);
-// 18 decimals of precision
-AggregatorV3Interface constant usdcEthFeed = AggregatorV3Interface(0x986b5E1e1755e3C2440e960477f25201B0a8bbD4);
-// 8 decimals of precision
-AggregatorV3Interface constant ethUsdFeed = AggregatorV3Interface(0x5f4eC3Df9cbd43714FE2740f5E3616155c5b8419);
-// 18 decimals of precision
-AggregatorV3Interface constant daiEthFeed = AggregatorV3Interface(0x773616E4d11A78F511299002da57A0a94577F1f4);
-
-IERC4626 constant vaultZero = IERC4626(address(0));
-IERC4626 constant sDaiVault = IERC4626(0x83F20F44975D03b1b09e64809B757c47f942BEeA);
+import "./helpers/Constants.sol";
 
 contract ChainlinkOracleTest is Test {
     function setUp() public {

test/WstEthStEthExchangeRateChainlinkAdapterTest.sol

@@ -0,0 +1,51 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+pragma solidity ^0.8.0;
+
+import "./helpers/Constants.sol";
+import "../lib/forge-std/src/Test.sol";
+import {ChainlinkOracle} from "../src/morpho-chainlink-v1/ChainlinkOracle.sol";
+import "../src/wsteth-exchange-rate-adapter/WstEthStEthExchangeRateChainlinkAdapter.sol";
+
+contract WstEthStEthExchangeRateChainlinkAdapterTest is Test {
+    IStEth internal constant ST_ETH = IStEth(0xae7ab96520DE3A18E5e111B5EaAb095312D7fE84);
+
+    WstEthStEthExchangeRateChainlinkAdapter internal oracle;
+    ChainlinkOracle internal chainlinkOracle;
+
+    function setUp() public {
+        vm.createSelectFork(vm.envString("ETH_RPC_URL"));
+        oracle = new WstEthStEthExchangeRateChainlinkAdapter();
+        chainlinkOracle = new ChainlinkOracle(
+            vaultZero, AggregatorV3Interface(address(oracle)), feedZero, feedZero, feedZero, 1, 18, 18
+        );
+    }
+
+    function testDecimals() public {
+        assertEq(oracle.decimals(), uint8(18));
+    }
+
+    function testDescription() public {
+        assertEq(oracle.description(), "wstETH/stETH exchange rate");
+    }
+
+    function testLatestRoundData() public {
+        (uint80 roundId, int256 answer, uint256 startedAt, uint256 updatedAt, uint80 answeredInRound) =
+            oracle.latestRoundData();
+        assertEq(roundId, 0);
+        assertEq(uint256(answer), ST_ETH.getPooledEthByShares(1 ether));
+        assertEq(startedAt, 0);
+        assertEq(updatedAt, 0);
+        assertEq(answeredInRound, 0);
+    }
+
+    function testLatestRoundDataBounds() public {
+        (, int256 answer,,,) = oracle.latestRoundData();
+        assertGe(uint256(answer), 1154690031824824994); // Exchange rate queried at block 19070943
+        assertLe(uint256(answer), 1.5e18); // Max bounds of the exchange rate. Should work for a long enough time.
+    }
+
+    function testOracleWstEthStEthExchangeRate() public {
+        (, int256 expectedPrice,,,) = oracle.latestRoundData();
+        assertEq(chainlinkOracle.price(), uint256(expectedPrice) * 10 ** (36 + 18 - 18 - 18));
+    }
+}

test/helpers/Constants.sol

@@ -0,0 +1,25 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+pragma solidity ^0.8.0;
+
+import {IERC4626, AggregatorV3Interface} from "../../src/morpho-chainlink-v1/ChainlinkOracle.sol";
+
+AggregatorV3Interface constant feedZero = AggregatorV3Interface(address(0));
+// 8 decimals of precision
+AggregatorV3Interface constant btcUsdFeed = AggregatorV3Interface(0xF4030086522a5bEEa4988F8cA5B36dbC97BeE88c);
+// 8 decimals of precision
+AggregatorV3Interface constant usdcUsdFeed = AggregatorV3Interface(0x8fFfFfd4AfB6115b954Bd326cbe7B4BA576818f6);
+// 18 decimals of precision
+AggregatorV3Interface constant btcEthFeed = AggregatorV3Interface(0xdeb288F737066589598e9214E782fa5A8eD689e8);
+// 8 decimals of precision
+AggregatorV3Interface constant wBtcBtcFeed = AggregatorV3Interface(0xfdFD9C85aD200c506Cf9e21F1FD8dd01932FBB23);
+// 18 decimals of precision
+AggregatorV3Interface constant stEthEthFeed = AggregatorV3Interface(0x86392dC19c0b719886221c78AB11eb8Cf5c52812);
+// 18 decimals of precision
+AggregatorV3Interface constant usdcEthFeed = AggregatorV3Interface(0x986b5E1e1755e3C2440e960477f25201B0a8bbD4);
+// 8 decimals of precision
+AggregatorV3Interface constant ethUsdFeed = AggregatorV3Interface(0x5f4eC3Df9cbd43714FE2740f5E3616155c5b8419);
+// 18 decimals of precision
+AggregatorV3Interface constant daiEthFeed = AggregatorV3Interface(0x773616E4d11A78F511299002da57A0a94577F1f4);
+
+IERC4626 constant vaultZero = IERC4626(address(0));
+IERC4626 constant sDaiVault = IERC4626(0x83F20F44975D03b1b09e64809B757c47f942BEeA);