Merge pull request #83 from morpho-org/refactor/various-improvements

Various improvements to wstETH adapter

Author: MerlinEgalite

src/wsteth-exchange-rate-adapter/WstEthEthExchangeRateChainlinkAdapter.sol renamed to src/wsteth-exchange-rate-adapter/WstEthStEthExchangeRateChainlinkAdapter.sol

@@ -4,17 +4,24 @@ pragma solidity 0.8.21;
 import {IStEth} from "./interfaces/IStEth.sol";
 import {MinimalAggregatorV3Interface} from "./interfaces/MinimalAggregatorV3Interface.sol";
 
-/// @title WstEthEthExchangeRateChainlinkAdapter
+/// @title WstEthStEthExchangeRateChainlinkAdapter
 /// @author Morpho Labs
 /// @custom:contact security@morpho.org
-/// @notice wstETH/ETH exchange rate price feed.
-/// @dev This contract should only be used as price feed for `ChainlinkOracle`.
-contract WstEthEthExchangeRateChainlinkAdapter is MinimalAggregatorV3Interface {
+/// @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;
-    string public constant description = "wstETH/ETH exchange rate";
+
+    /// @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.

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

@@ -3,9 +3,13 @@ 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

test/WstEthEthExchangeRateChainlinkAdapterTest.sol renamed to test/WstEthStEthExchangeRateChainlinkAdapterTest.sol

@@ -4,17 +4,17 @@ 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/WstEthEthExchangeRateChainlinkAdapter.sol";
+import "../src/wsteth-exchange-rate-adapter/WstEthStEthExchangeRateChainlinkAdapter.sol";
 
-contract WstEthEthExchangeRateChainlinkAdapterTest is Test {
+contract WstEthStEthExchangeRateChainlinkAdapterTest is Test {
     IStEth internal constant ST_ETH = IStEth(0xae7ab96520DE3A18E5e111B5EaAb095312D7fE84);
 
-    WstEthEthExchangeRateChainlinkAdapter internal oracle;
+    WstEthStEthExchangeRateChainlinkAdapter internal oracle;
     ChainlinkOracle internal chainlinkOracle;
 
     function setUp() public {
         vm.createSelectFork(vm.envString("ETH_RPC_URL"));
-        oracle = new WstEthEthExchangeRateChainlinkAdapter();
+        oracle = new WstEthStEthExchangeRateChainlinkAdapter();
         chainlinkOracle = new ChainlinkOracle(
             vaultZero, AggregatorV3Interface(address(oracle)), feedZero, feedZero, feedZero, 1, 18, 18
         );
@@ -25,7 +25,7 @@ contract WstEthEthExchangeRateChainlinkAdapterTest is Test {
     }
 
     function testDescription() public {
-        assertEq(oracle.description(), "wstETH/ETH exchange rate");
+        assertEq(oracle.description(), "wstETH/stETH exchange rate");
     }
 
     function testLatestRoundData() public {
@@ -44,7 +44,7 @@ contract WstEthEthExchangeRateChainlinkAdapterTest is Test {
         assertLe(uint256(answer), 1.5e18); // Max bounds of the exchange rate. Should work for a long enough time.
     }
 
-    function testOracleWstEthEthExchangeRate() public {
+    function testOracleWstEthStEthExchangeRate() public {
         (, int256 expectedPrice,,,) = oracle.latestRoundData();
         assertEq(chainlinkOracle.price(), uint256(expectedPrice) * 10 ** (36 + 18 - 18 - 18));
     }