test(contracts): add comprehensive test coverage for Constants library (#18267)

- Split EIP1967 constants test into separate tests for better clarity
- Add tests for ESTIMATION_ADDRESS, DEFAULT_L2_SENDER, GUARD_STORAGE_SLOT, ETHER, and DEPOSITOR_ACCOUNT constants
- Add test for DEFAULT_RESOURCE_CONFIG() function covering all 6 struct fields
- Import IResourceMetering interface for ResourceConfig struct testing

All 8 tests pass successfully.

Co-authored-by: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>

Author: devin-ai-integration[bot]

packages/contracts-bedrock/test/libraries/Constants.t.sol

@@ -3,15 +3,56 @@ pragma solidity 0.8.15;
 
 import { Test } from "forge-std/Test.sol";
 import { Constants } from "src/libraries/Constants.sol";
+import { IResourceMetering } from "interfaces/L1/IResourceMetering.sol";
 
-/// @title Constants_Constants_Test
+/// @title Constants_Test
 /// @notice Tests the constant values defined in the `Constants` library.
 contract Constants_Test is Test {
-    /// @notice Check EIP1967 related constants.
-    function test_eip1967Constants_succeeds() external pure {
+    /// @notice Verify ESTIMATION_ADDRESS constant value.
+    function test_estimationAddress_succeeds() external pure {
+        assertEq(Constants.ESTIMATION_ADDRESS, address(1));
+    }
+
+    /// @notice Verify DEFAULT_L2_SENDER constant value.
+    function test_defaultL2Sender_succeeds() external pure {
+        assertEq(Constants.DEFAULT_L2_SENDER, 0x000000000000000000000000000000000000dEaD);
+    }
+
+    /// @notice Verify EIP1967 proxy implementation storage slot.
+    function test_proxyImplementationAddress_succeeds() external pure {
         assertEq(
             bytes32(uint256(keccak256("eip1967.proxy.implementation")) - 1), Constants.PROXY_IMPLEMENTATION_ADDRESS
         );
+    }
+
+    /// @notice Verify EIP1967 proxy admin storage slot.
+    function test_proxyOwnerAddress_succeeds() external pure {
         assertEq(bytes32(uint256(keccak256("eip1967.proxy.admin")) - 1), Constants.PROXY_OWNER_ADDRESS);
     }
+
+    /// @notice Verify GUARD_STORAGE_SLOT constant value.
+    function test_guardStorageSlot_succeeds() external pure {
+        assertEq(keccak256("guard_manager.guard.address"), Constants.GUARD_STORAGE_SLOT);
+    }
+
+    /// @notice Verify ETHER constant value.
+    function test_ether_succeeds() external pure {
+        assertEq(Constants.ETHER, 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE);
+    }
+
+    /// @notice Verify DEPOSITOR_ACCOUNT constant value.
+    function test_depositorAccount_succeeds() external pure {
+        assertEq(Constants.DEPOSITOR_ACCOUNT, 0xDeaDDEaDDeAdDeAdDEAdDEaddeAddEAdDEAd0001);
+    }
+
+    /// @notice Verify DEFAULT_RESOURCE_CONFIG returns expected values.
+    function test_defaultResourceConfig_succeeds() external pure {
+        IResourceMetering.ResourceConfig memory config = Constants.DEFAULT_RESOURCE_CONFIG();
+        assertEq(config.maxResourceLimit, 20_000_000);
+        assertEq(config.elasticityMultiplier, 10);
+        assertEq(config.baseFeeMaxChangeDenominator, 8);
+        assertEq(config.minimumBaseFee, 1 gwei);
+        assertEq(config.systemTxMaxGas, 1_000_000);
+        assertEq(config.maximumBaseFee, type(uint128).max);
+    }
 }