Merge pull request #5499 from ethereum-optimism/refcell/test/sysconfig

chore(contracts-bedrock): ResourceConfig Sherlock Test

packages/contracts-bedrock/.gas-snapshot

@@ -395,14 +395,15 @@ RLPWriter_writeUint_Test:test_writeUint_smallint_succeeds() (gas: 7280)
 RLPWriter_writeUint_Test:test_writeUint_zero_succeeds() (gas: 7749)
 ResolvedDelegateProxy_Test:test_fallback_addressManagerNotSet_reverts() (gas: 605906)
 ResolvedDelegateProxy_Test:test_fallback_delegateCallBar_reverts() (gas: 24783)
-ResourceMetering_Test:test_meter_initialResourceParams_succeeds() (gas: 10368)
-ResourceMetering_Test:test_meter_updateNoGasDelta_succeeds() (gas: 2009696)
-ResourceMetering_Test:test_meter_updateOneEmptyBlock_succeeds() (gas: 18860)
-ResourceMetering_Test:test_meter_updateParamsNoChange_succeeds() (gas: 15149)
-ResourceMetering_Test:test_meter_updateTenEmptyBlocks_succeeds() (gas: 21713)
-ResourceMetering_Test:test_meter_updateTwoEmptyBlocks_succeeds() (gas: 21669)
-ResourceMetering_Test:test_meter_useMax_succeeds() (gas: 20018715)
-ResourceMetering_Test:test_meter_useMoreThanMax_reverts() (gas: 17505)
+ResourceMetering_Test:test_meter_denominatorEq1_reverts() (gas: 20024064)
+ResourceMetering_Test:test_meter_initialResourceParams_succeeds() (gas: 12423)
+ResourceMetering_Test:test_meter_updateNoGasDelta_succeeds() (gas: 2011591)
+ResourceMetering_Test:test_meter_updateOneEmptyBlock_succeeds() (gas: 20894)
+ResourceMetering_Test:test_meter_updateParamsNoChange_succeeds() (gas: 17217)
+ResourceMetering_Test:test_meter_updateTenEmptyBlocks_succeeds() (gas: 23747)
+ResourceMetering_Test:test_meter_updateTwoEmptyBlocks_succeeds() (gas: 23703)
+ResourceMetering_Test:test_meter_useMax_succeeds() (gas: 20020816)
+ResourceMetering_Test:test_meter_useMoreThanMax_reverts() (gas: 19549)
 SafeCall_call_Test:test_callWithMinGas_noLeakageHigh_succeeds() (gas: 2075873614)
 SafeCall_call_Test:test_callWithMinGas_noLeakageLow_succeeds() (gas: 753665282)
 Semver_Test:test_behindProxy_succeeds() (gas: 506748)

packages/contracts-bedrock/contracts/test/ResourceMetering.t.sol

@@ -7,25 +7,28 @@ import { Proxy } from "../universal/Proxy.sol";
 import { Constants } from "../libraries/Constants.sol";
 
 contract MeterUser is ResourceMetering {
+    ResourceMetering.ResourceConfig public innerConfig;
+
     constructor() {
         initialize();
+        innerConfig = Constants.DEFAULT_RESOURCE_CONFIG();
     }
 
     function initialize() public initializer {
         __ResourceMetering_init();
     }
 
-    function resourceConfig() public pure returns (ResourceMetering.ResourceConfig memory) {
+    function resourceConfig() public view returns (ResourceMetering.ResourceConfig memory) {
         return _resourceConfig();
     }
 
     function _resourceConfig()
         internal
-        pure
+        view
         override
         returns (ResourceMetering.ResourceConfig memory)
     {
-        return Constants.DEFAULT_RESOURCE_CONFIG();
+        return innerConfig;
     }
 
     function use(uint64 _amount) public metered(_amount) {}
@@ -41,6 +44,10 @@ contract MeterUser is ResourceMetering {
             prevBlockNum: _prevBlockNum
         });
     }
+
+    function setParams(ResourceMetering.ResourceConfig memory newConfig) public {
+        innerConfig = newConfig;
+    }
 }
 
 /**
@@ -134,6 +141,32 @@ contract ResourceMetering_Test is Test {
         assertEq(postBaseFee, 2125000000);
     }
 
+    /**
+     * @notice This tests that the metered modifier reverts if
+     *         the ResourceConfig baseFeeMaxChangeDenominator
+     *         is set to 1.
+     *         Since the metered modifier internally calls
+     *         solmate's powWad function, it will revert
+     *         with the error string "UNDEFINED" since the
+     *         first parameter will be computed as 0.
+     */
+    function test_meter_denominatorEq1_reverts() external {
+        ResourceMetering.ResourceConfig memory rcfg = meter.resourceConfig();
+        uint64 target = uint64(rcfg.maxResourceLimit) / uint64(rcfg.elasticityMultiplier);
+        uint64 elasticityMultiplier = uint64(rcfg.elasticityMultiplier);
+        rcfg.baseFeeMaxChangeDenominator = 1;
+        meter.setParams(rcfg);
+        meter.use(target * elasticityMultiplier);
+
+        (, uint64 prevBoughtGas, ) = meter.params();
+        assertEq(prevBoughtGas, target * elasticityMultiplier);
+
+        vm.roll(initialBlockNum + 2);
+
+        vm.expectRevert("UNDEFINED");
+        meter.use(0);
+    }
+
     function test_meter_useMoreThanMax_reverts() external {
         ResourceMetering.ResourceConfig memory rcfg = meter.resourceConfig();
         uint64 target = uint64(rcfg.maxResourceLimit) / uint64(rcfg.elasticityMultiplier);