feat: create OracleLib to check for stale pricefeed data

dt6120 · Nov 8, 2024 · deb2f16 · deb2f16
1 parent fc82fa4
commit deb2f16
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Showing 3 changed files with 32 additions and 2 deletions.
diff --git a/src/DSCEngine.sol b/src/DSCEngine.sol
@@ -7,6 +7,7 @@ import {AggregatorV3Interface} from "@chainlink/contracts/shared/interfaces/Aggr
 
 import {IDSCEngine} from "./interfaces/IDSCEngine.sol";
 import {DecentralizedStablecoin} from "./DecentralizedStablecoin.sol";
+import {OracleLib} from "./libraries/OracleLib.sol";
 
 /**
  * @title DSCEngine
@@ -19,6 +20,8 @@ import {DecentralizedStablecoin} from "./DecentralizedStablecoin.sol";
  *
  */
 contract DSCEngine is IDSCEngine, ReentrancyGuard {
+    using OracleLib for AggregatorV3Interface;
+
     uint256 private constant ADDITIONAL_PRICE_FEED_PRECISION = 1e10;
     uint256 private constant PRECISION = 1e18;
     uint256 private constant LIQUIDATION_THRESHOLD = 50;
@@ -251,13 +254,13 @@ contract DSCEngine is IDSCEngine, ReentrancyGuard {
      */
     function getUsdValue(address token, uint256 amount) public view returns (uint256 usdValue) {
         address priceFeed = s_tokenToPriceFeed[token];
-        (, int256 unitUsdPrice,,,) = AggregatorV3Interface(priceFeed).latestRoundData();
+        (, int256 unitUsdPrice,,,) = AggregatorV3Interface(priceFeed).staleCheckLatestRoundData();
         usdValue = ((uint256(unitUsdPrice) * ADDITIONAL_PRICE_FEED_PRECISION) * amount) / PRECISION;
     }
 
     function getTokenAmountFromUsdValue(address token, uint256 amount) public view returns (uint256 tokenAmount) {
         address priceFeed = s_tokenToPriceFeed[token];
-        (, int256 unitUsdPrice,,,) = AggregatorV3Interface(priceFeed).latestRoundData();
+        (, int256 unitUsdPrice,,,) = AggregatorV3Interface(priceFeed).staleCheckLatestRoundData();
         tokenAmount = amount * PRECISION / (uint256(unitUsdPrice) * ADDITIONAL_PRICE_FEED_PRECISION);
     }
 
@@ -374,6 +377,10 @@ contract DSCEngine is IDSCEngine, ReentrancyGuard {
         adjustedCollateralUsdValue = collateralUsdValue * LIQUIDATION_THRESHOLD / LIQUIDATION_PRECISION;
     }
 
+    function getAdjustedUsdValue(uint256 amount) external pure returns (uint256 adjustedUsdValue) {
+        adjustedUsdValue = amount * LIQUIDATION_THRESHOLD / LIQUIDATION_PRECISION;
+    }
+
     function calculateHealthFactor(uint256 totalDscMinted, uint256 totalCollateralUsdValue)
         external
         pure

diff --git a/src/interfaces/IDSCEngine.sol b/src/interfaces/IDSCEngine.sol
@@ -32,6 +32,7 @@ interface IDSCEngine {
     function getMinHealthFactor() external pure returns (uint256);
     function getPriceFeed(address token) external view returns (address);
     function getUserCollateralDepositAmount(address user, address token) external view returns (uint256);
+    function getAdjustedUsdValue(uint256 amount) external pure returns (uint256);
     function getDscMinted(address user) external view returns (uint256);
     function getCollateralTokens() external view returns (address[] memory);
     function getMaxMintableDsc(address user) external view returns (uint256);

diff --git a/src/libraries/OracleLib.sol b/src/libraries/OracleLib.sol
@@ -0,0 +1,22 @@
+// SPDX-License-Identifier: MIT
+pragma solidity 0.8.28;
+
+import {AggregatorV3Interface} from "@chainlink/contracts/shared/interfaces/AggregatorV3Interface.sol";
+
+library OracleLib {
+    error OracleLib__StalePrice();
+
+    uint256 public constant TIMEOUT = 1 hours;
+
+    function staleCheckLatestRoundData(AggregatorV3Interface priceFeed)
+        public
+        view
+        returns (uint80 roundId, int256 answer, uint256 startedAt, uint256 updatedAt, uint80 answeredInRound)
+    {
+        (roundId, answer, startedAt, updatedAt, answeredInRound) = priceFeed.latestRoundData();
+
+        if (block.timestamp - updatedAt > TIMEOUT) {
+            revert OracleLib__StalePrice();
+        }
+    }
+}