Add method to view implementation

.gas-snapshot

@@ -1,52 +1,53 @@
-AddOwnerAddressTest:testEmitsAddOwner() (gas: 92374)
-AddOwnerAddressTest:testIncreasesOwnerIndex() (gas: 90614)
-AddOwnerAddressTest:testRevertsIfAlreadyOwner() (gas: 93137)
-AddOwnerAddressTest:testRevertsIfCalledByNonOwner() (gas: 11754)
-AddOwnerAddressTest:testSetsIsOwner() (gas: 90476)
-AddOwnerAddressTest:testSetsOwnerAtIndex() (gas: 98897)
-AddOwnerPublicKeyTest:testEmitsAddOwner() (gas: 115509)
-AddOwnerPublicKeyTest:testFuzzIsOwnerPublicKey(bytes32,bytes32) (runs: 256, μ: 115333, ~: 115333)
-AddOwnerPublicKeyTest:testRevertsIfAlreadyOwner() (gas: 116301)
-AddOwnerPublicKeyTest:testRevertsIfCalledByNonOwner() (gas: 11744)
-AddOwnerPublicKeyTest:testSetsIsOwner() (gas: 113775)
-AddOwnerPublicKeyTest:testSetsOwnerAtIndex() (gas: 128543)
-CoinbaseSmartWallet1271InputGeneratorTest:testGetReplaySafeHashForDeployedAccount() (gas: 308664)
-CoinbaseSmartWallet1271InputGeneratorTest:testGetReplaySafeHashForUndeployedAccount() (gas: 291435)
+AddOwnerAddressTest:testEmitsAddOwner() (gas: 92393)
+AddOwnerAddressTest:testIncreasesOwnerIndex() (gas: 90633)
+AddOwnerAddressTest:testRevertsIfAlreadyOwner() (gas: 93175)
+AddOwnerAddressTest:testRevertsIfCalledByNonOwner() (gas: 11764)
+AddOwnerAddressTest:testSetsIsOwner() (gas: 90495)
+AddOwnerAddressTest:testSetsOwnerAtIndex() (gas: 98916)
+AddOwnerPublicKeyTest:testEmitsAddOwner() (gas: 115528)
+AddOwnerPublicKeyTest:testFuzzIsOwnerPublicKey(bytes32,bytes32) (runs: 256, μ: 115352, ~: 115352)
+AddOwnerPublicKeyTest:testRevertsIfAlreadyOwner() (gas: 116339)
+AddOwnerPublicKeyTest:testRevertsIfCalledByNonOwner() (gas: 11754)
+AddOwnerPublicKeyTest:testSetsIsOwner() (gas: 113794)
+AddOwnerPublicKeyTest:testSetsOwnerAtIndex() (gas: 128562)
+CoinbaseSmartWallet1271InputGeneratorTest:testGetReplaySafeHashForDeployedAccount() (gas: 308658)
+CoinbaseSmartWallet1271InputGeneratorTest:testGetReplaySafeHashForUndeployedAccount() (gas: 291429)
 CoinbaseSmartWalletFactoryTest:testDeployDeterministicPassValues() (gas: 267742)
 CoinbaseSmartWalletFactoryTest:test_CreateAccount_ReturnsPredeterminedAddress_WhenAccountAlreadyExists() (gas: 287406)
 CoinbaseSmartWalletFactoryTest:test_createAccountDeploysToPredeterminedAddress() (gas: 269093)
 CoinbaseSmartWalletFactoryTest:test_createAccountSetsOwnersCorrectly() (gas: 277981)
+CoinbaseSmartWalletFactoryTest:test_implementation_returnsExpectedAddress() (gas: 7676)
 CoinbaseSmartWalletFactoryTest:test_revertsIfNoOwners() (gas: 29214)
 ERC1271Test:test_returnsExpectedDomainHashWhenProxy() (gas: 15406)
 MultiOwnableInitializeTest:testRevertsIfLength32ButLargerThanAddress() (gas: 78927)
 MultiOwnableInitializeTest:testRevertsIfLength32NotAddress() (gas: 78908)
 MultiOwnableInitializeTest:testRevertsIfLengthNot32Or64() (gas: 101211)
-RemoveOwnerAtIndexTest:testEmitsRemoveOwner() (gas: 33299)
-RemoveOwnerAtIndexTest:testRemovesOwner() (gas: 32682)
-RemoveOwnerAtIndexTest:testRemovesOwnerAtIndex() (gas: 27567)
-RemoveOwnerAtIndexTest:testRevertsIfCalledByNonOwner() (gas: 11332)
-RemoveOwnerAtIndexTest:testRevertsIfNoOwnerAtIndex() (gas: 16648)
-TestCanSkipChainIdValidation:test_approvedSelectorsReturnTrue() (gas: 15845)
-TestCanSkipChainIdValidation:test_otherSelectorsReturnFalse() (gas: 12469)
-TestExecuteWithoutChainIdValidation:testExecute() (gas: 424705)
-TestExecuteWithoutChainIdValidation:testExecuteBatch() (gas: 729086)
-TestExecuteWithoutChainIdValidation:testExecuteBatch(uint256) (runs: 256, μ: 3409748, ~: 3278930)
-TestExecuteWithoutChainIdValidation:test__codesize() (gas: 49006)
-TestExecuteWithoutChainIdValidation:test__codesize() (gas: 49241)
-TestExecuteWithoutChainIdValidation:test_canChangeOwnerWithoutChainId() (gas: 287917)
-TestExecuteWithoutChainIdValidation:test_cannotCallExec() (gas: 220047)
-TestExecuteWithoutChainIdValidation:test_revertsIfCallerNotEntryPoint() (gas: 8620)
+RemoveOwnerAtIndexTest:testEmitsRemoveOwner() (gas: 33270)
+RemoveOwnerAtIndexTest:testRemovesOwner() (gas: 32653)
+RemoveOwnerAtIndexTest:testRemovesOwnerAtIndex() (gas: 27538)
+RemoveOwnerAtIndexTest:testRevertsIfCalledByNonOwner() (gas: 11308)
+RemoveOwnerAtIndexTest:testRevertsIfNoOwnerAtIndex() (gas: 16624)
+TestCanSkipChainIdValidation:test_approvedSelectorsReturnTrue() (gas: 15933)
+TestCanSkipChainIdValidation:test_otherSelectorsReturnFalse() (gas: 12513)
+TestExecuteWithoutChainIdValidation:testExecute() (gas: 424907)
+TestExecuteWithoutChainIdValidation:testExecuteBatch() (gas: 729143)
+TestExecuteWithoutChainIdValidation:testExecuteBatch(uint256) (runs: 256, μ: 3422948, ~: 3288297)
+TestExecuteWithoutChainIdValidation:test__codesize() (gas: 49053)
+TestExecuteWithoutChainIdValidation:test__codesize() (gas: 49288)
+TestExecuteWithoutChainIdValidation:test_canChangeOwnerWithoutChainId() (gas: 287727)
+TestExecuteWithoutChainIdValidation:test_cannotCallExec() (gas: 220025)
+TestExecuteWithoutChainIdValidation:test_revertsIfCallerNotEntryPoint() (gas: 8598)
 TestExecuteWithoutChainIdValidation:test_revertsIfWrongNonceKey() (gas: 62275)
-TestExecuteWithoutChainIdValidation:test_revertsWithReservedNonce() (gas: 82302)
-TestInitialize:testInitialize() (gas: 21122)
-TestInitialize:test_cannotInitImplementation() (gas: 2708253)
-TestIsValidSignature:testReturnsInvalidIfPasskeySigButWrongOwnerLength() (gas: 39497)
-TestIsValidSignature:testRevertsIfEthereumSignatureButWrongOwnerLength() (gas: 24068)
-TestIsValidSignature:testSmartWalletSigner() (gas: 2981137)
-TestIsValidSignature:testValidateSignatureWithEOASigner() (gas: 24950)
-TestIsValidSignature:testValidateSignatureWithEOASignerFailsWithWrongSigner() (gas: 23880)
-TestIsValidSignature:testValidateSignatureWithPasskeySigner() (gas: 421284)
-TestIsValidSignature:testValidateSignatureWithPasskeySignerFailsBadOwnerIndex() (gas: 34986)
-TestIsValidSignature:testValidateSignatureWithPasskeySignerFailsWithWrongBadSignature() (gas: 428750)
-TestUpgradeToAndCall:testUpgradeToAndCall() (gas: 23839)
-TestValidateUserOp:testValidateUserOp() (gas: 447113)
+TestExecuteWithoutChainIdValidation:test_revertsWithReservedNonce() (gas: 82324)
+TestInitialize:testInitialize() (gas: 21034)
+TestInitialize:test_cannotInitImplementation() (gas: 2714468)
+TestIsValidSignature:testReturnsInvalidIfPasskeySigButWrongOwnerLength() (gas: 39469)
+TestIsValidSignature:testRevertsIfEthereumSignatureButWrongOwnerLength() (gas: 24040)
+TestIsValidSignature:testSmartWalletSigner() (gas: 2990421)
+TestIsValidSignature:testValidateSignatureWithEOASigner() (gas: 24922)
+TestIsValidSignature:testValidateSignatureWithEOASignerFailsWithWrongSigner() (gas: 23877)
+TestIsValidSignature:testValidateSignatureWithPasskeySigner() (gas: 421256)
+TestIsValidSignature:testValidateSignatureWithPasskeySignerFailsBadOwnerIndex() (gas: 34958)
+TestIsValidSignature:testValidateSignatureWithPasskeySignerFailsWithWrongBadSignature() (gas: 428722)
+TestUpgradeToAndCall:testUpgradeToAndCall() (gas: 23836)
+TestValidateUserOp:testValidateUserOp() (gas: 447275)

src/CoinbaseSmartWallet.sol

@@ -235,6 +235,15 @@ contract CoinbaseSmartWallet is MultiOwnable, UUPSUpgradeable, Receiver, ERC1271
         return keccak256(abi.encode(UserOperationLib.hash(userOp), entryPoint()));
     }
 
+    /// @notice Returns the implementation of the ERC1967 proxy.
+    ///
+    /// @return $ the address the implementation contract
+    function implementation() public view returns (address $) {
+        assembly {
+            $ := sload(_ERC1967_IMPLEMENTATION_SLOT)
+        }
+    }
+
     /// @notice Check if the given function selector is whitelisted to skip the chain ID validation.
     ///
     /// @param functionSelector The function selector to check.

test/CoinbaseSmartWallet/ExecuteWithoutChainIdValidation.t.sol

@@ -42,7 +42,7 @@ contract TestExecuteWithoutChainIdValidation is SmartWalletTestBase {
         UserOperation memory userOp = _getUserOpWithSignature();
         vm.expectEmit(true, true, true, true);
         emit IEntryPoint.UserOperationEvent(
-            entryPoint.getUserOpHash(userOp), userOp.sender, address(0), userOp.nonce, false, 0, 48027
+            entryPoint.getUserOpHash(userOp), userOp.sender, address(0), userOp.nonce, false, 0, 48005
         );
         _sendUserOperation(userOp);
     }

test/CoinbaseSmartWalletFactory.t.sol

@@ -51,4 +51,8 @@ contract CoinbaseSmartWalletFactoryTest is Test {
         CoinbaseSmartWallet a = factory.createAccount{value: 1e18}(owners, 0);
         assertEq(address(a).balance, 1e18);
     }
+
+    function test_implementation_returnsExpectedAddress() public {
+        assertEq(factory.implementation(), address(account));
+    }
 }