feat: mocking AggregatorV3Interface + add different ethPrice configs …

…for each network

script/HelperConfig.s.sol

@@ -6,12 +6,15 @@
 pragma solidity ^0.8.28;
 
 import {Script} from "forge-std/Script.sol";
+import {MockV3Aggregator} from "../test/mocks/MockV3Aggregator.sol";
 
-contract HelperConfig {
+contract HelperConfig is Script {
     // If we are on a local anvil, we deploy mocks
     // Otherwise, grab the existing address from the live network
 
     NetworkConfig public activeNetworkConfig;
+    uint8 public constant DECIMALS = 8;
+    int256 public constant INITIAL_PRICE = 2000e8;
 
     struct NetworkConfig {
         address priceFeed;
@@ -23,7 +26,7 @@ contract HelperConfig {
         } else if (block.chainid == 1) {
             activeNetworkConfig = getMainnetEthConfig();
         } else {
-            activeNetworkConfig = getAnvilEthConfig();
+            activeNetworkConfig = getOrCreateAnvilEthConfig();
         }
     }
 
@@ -42,7 +45,23 @@ contract HelperConfig {
         return mainnetConfig;
     }
 
-    function getAnvilEthConfig() public pure returns (NetworkConfig memory) {
+    function getOrCreateAnvilEthConfig() public returns (NetworkConfig memory) {
+        if (activeNetworkConfig.priceFeed != address(0)) {
+            return activeNetworkConfig;
+        }
         // price feed address
+        // 1. Deploy the mocks
+        // 2. Return the mock address
+        vm.startBroadcast();
+        MockV3Aggregator mockPriceFeed = new MockV3Aggregator(
+            DECIMALS,
+            INITIAL_PRICE
+        );
+        vm.stopBroadcast();
+
+        NetworkConfig memory anvilConfig = NetworkConfig({
+            priceFeed: address(mockPriceFeed)
+        });
+        return anvilConfig;
     }
 }

test/mocks/MockV3Aggregator.sol

@@ -0,0 +1,99 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.0;
+
+import {AggregatorV3Interface} from "@chainlink/contracts/src/v0.8/shared/interfaces/AggregatorV3Interface.sol";
+
+/**
+ * @title MockV3Aggregator
+ * @notice Based on the FluxAggregator contract
+ * @notice Use this contract when you need to test
+ * other contract's ability to read data from an
+ * aggregator contract, but how the aggregator got
+ * its answer is unimportant
+ */
+contract MockV3Aggregator is AggregatorV3Interface {
+    uint256 public constant version = 4;
+
+    uint8 public decimals;
+    int256 public latestAnswer;
+    uint256 public latestTimestamp;
+    uint256 public latestRound;
+
+    mapping(uint256 => int256) public getAnswer;
+    mapping(uint256 => uint256) public getTimestamp;
+    mapping(uint256 => uint256) private getStartedAt;
+
+    constructor(uint8 _decimals, int256 _initialAnswer) {
+        decimals = _decimals;
+        updateAnswer(_initialAnswer);
+    }
+
+    function updateAnswer(int256 _answer) public {
+        latestAnswer = _answer;
+        latestTimestamp = block.timestamp;
+        latestRound++;
+        getAnswer[latestRound] = _answer;
+        getTimestamp[latestRound] = block.timestamp;
+        getStartedAt[latestRound] = block.timestamp;
+    }
+
+    function updateRoundData(
+        uint80 _roundId,
+        int256 _answer,
+        uint256 _timestamp,
+        uint256 _startedAt
+    ) public {
+        latestRound = _roundId;
+        latestAnswer = _answer;
+        latestTimestamp = _timestamp;
+        getAnswer[latestRound] = _answer;
+        getTimestamp[latestRound] = _timestamp;
+        getStartedAt[latestRound] = _startedAt;
+    }
+
+    function getRoundData(
+        uint80 _roundId
+    )
+        external
+        view
+        returns (
+            uint80 roundId,
+            int256 answer,
+            uint256 startedAt,
+            uint256 updatedAt,
+            uint80 answeredInRound
+        )
+    {
+        return (
+            _roundId,
+            getAnswer[_roundId],
+            getStartedAt[_roundId],
+            getTimestamp[_roundId],
+            _roundId
+        );
+    }
+
+    function latestRoundData()
+        external
+        view
+        returns (
+            uint80 roundId,
+            int256 answer,
+            uint256 startedAt,
+            uint256 updatedAt,
+            uint80 answeredInRound
+        )
+    {
+        return (
+            uint80(latestRound),
+            getAnswer[latestRound],
+            getStartedAt[latestRound],
+            getTimestamp[latestRound],
+            uint80(latestRound)
+        );
+    }
+
+    function description() external pure returns (string memory) {
+        return "v0.6/test/mock/MockV3Aggregator.sol";
+    }
+}