Adapted tests to work for Mainnet fork

contracts/mock/MockFallbackCaller.sol

@@ -0,0 +1,83 @@
+// SPDX-License-Identifier: MIT
+// File: Interfaces/IFallbackCaller.sol
+
+pragma solidity 0.8.17;
+
+interface IFallbackCaller {
+  // --- Events ---
+  event FallbackTimeOutChanged(uint256 _oldTimeOut, uint256 _newTimeOut);
+
+  // --- Function External View ---
+
+  // NOTE: The fallback oracle must always return its answer scaled to 18 decimals where applicable
+  //       The system will assume an 18 decimal response for efficiency.
+  function getFallbackResponse() external view returns (uint256, uint256, bool);
+
+  // NOTE: this returns the timeout window interval for the fallback oracle instead
+  // of storing in the `PriceFeed` contract is retrieve for the `FallbackCaller`
+  function fallbackTimeout() external view returns (uint256);
+
+  // --- Function External Setter ---
+
+  function setFallbackTimeout(uint256 newFallbackTimeout) external;
+}
+// File: contracts/MockFallbackCaller.sol
+
+pragma solidity 0.8.17;
+
+contract MockFallbackCaller is IFallbackCaller {
+  uint256 public _answer;
+  uint256 public _timestampRetrieved;
+  uint256 public _fallbackTimeout = 90000; // NOTE: MAYBE BEST TO CUSTOMIZE
+  bool public _success;
+  uint256 public _initAnswer;
+
+  bool public getFallbackResponseRevert;
+  bool public fallbackTimeoutRevert;
+
+  constructor(uint256 answer) {
+    _initAnswer = answer;
+  }
+
+  function setGetFallbackResponseRevert() external {
+    getFallbackResponseRevert = !getFallbackResponseRevert;
+  }
+
+  function setFallbackTimeoutRevert() external {
+    fallbackTimeoutRevert = !fallbackTimeoutRevert;
+  }
+
+  function setFallbackResponse(
+    uint256 answer,
+    uint256 timestampRetrieved,
+    bool success
+  ) external {
+    _answer = answer;
+    _timestampRetrieved = timestampRetrieved;
+    _success = success;
+  }
+
+  function setFallbackTimeout(uint256 newFallbackTimeout) external {
+    uint256 oldTimeOut = _fallbackTimeout;
+    _fallbackTimeout = newFallbackTimeout;
+    emit FallbackTimeOutChanged(oldTimeOut, newFallbackTimeout);
+  }
+
+  function getFallbackResponse()
+    external
+    view
+    returns (uint256, uint256, bool)
+  {
+    if (getFallbackResponseRevert) {
+      require(1 == 0, "getFallbackResponse reverted");
+    }
+    return (_answer, _timestampRetrieved, _success);
+  }
+
+  function fallbackTimeout() external view returns (uint256) {
+    if (fallbackTimeoutRevert) {
+      require(1 == 0, "fallbackTimeout reverted");
+    }
+    return _fallbackTimeout;
+  }
+}