TimelockProposal Arbitrum L1 example

.solhintrc

@@ -18,6 +18,7 @@
     	"contract-name-camelcase": "off",
         "no-unused-import": "error",
         "explicit-types": "off",
-        "const-name-snakecase": "off"
+        "const-name-snakecase": "off",
+        "gas-custom-errors": "off"
     }
 }

addresses/Addresses.json

@@ -148,5 +148,35 @@
         "chainId": 1,
         "name": "OPTIMISM_L1_NFT_BRIDGE_IMPLEMENTATION",
         "isContract": true
+    },
+    {
+        "addr": "0xE6841D92B0C345144506576eC13ECf5103aC7f49",
+        "chainId": 1,
+        "name": "ARBITRUM_L1_TIMELOCK",
+        "isContract": true
+    },
+    {
+        "addr": "0x3ffFbAdAF827559da092217e474760E2b2c3CeDd",
+        "chainId": 1,
+        "name": "ARBITRUM_L1_UPGRADE_EXECUTOR",
+        "isContract": true
+    },
+    {
+        "addr": "0x9aD46fac0Cf7f790E5be05A0F15223935A0c0aDa",
+        "chainId": 1,
+        "name": "ARBITRUM_L1_PROXY_ADMIN",
+        "isContract": true
+    },
+    {
+        "addr": "0xd92023e9d9911199a6711321d1277285e6d4e2db",
+        "chainId": 1,
+        "name": "ARBITRUM_L1_WETH_GATEWAY_PROXY",
+        "isContract": true
+    },
+    {
+        "addr": "0x8315177aB297bA92A06054cE80a67Ed4DBd7ed3a",
+        "chainId": 1,
+        "name": "ARBITRUM_BRIDGE",
+        "isContract": true
     }
 ]

mocks/MockMultisigProposal.sol

@@ -5,15 +5,10 @@ import {Addresses} from "@addresses/Addresses.sol";
 
 import {MultisigProposal} from "@proposals/MultisigProposal.sol";
 
-import {Vault} from "@mocks/Vault.sol";
+import {IProxy} from "@interface/IProxy.sol";
+import {IProxyAdmin} from "@interface/IProxyAdmin.sol";
 
-interface ProxyAdmin {
-    function upgrade(address proxy, address implementation) external;
-}
-
-interface Proxy {
-    function implementation() external view returns (address);
-}
+import {MockUpgrade} from "@mocks/MockUpgrade.sol";
 
 contract MockMultisigProposal is MultisigProposal {
     function name() public pure override returns (string memory) {
@@ -35,7 +30,7 @@ contract MockMultisigProposal is MultisigProposal {
 
     function deploy() public override {
         if (!addresses.isAddressSet("OPTIMISM_L1_NFT_BRIDGE_IMPLEMENTATION")) {
-            address l1NFTBridgeImplementation = address(new Vault());
+            address l1NFTBridgeImplementation = address(new MockUpgrade());
 
             addresses.addAddress(
                 "OPTIMISM_L1_NFT_BRIDGE_IMPLEMENTATION",
@@ -50,7 +45,7 @@ contract MockMultisigProposal is MultisigProposal {
         override
         buildModifier(addresses.getAddress("OPTIMISM_MULTISIG"))
     {
-        ProxyAdmin proxy = ProxyAdmin(
+        IProxyAdmin proxy = IProxyAdmin(
             addresses.getAddress("OPTIMISM_PROXY_ADMIN")
         );
 
@@ -67,10 +62,11 @@ contract MockMultisigProposal is MultisigProposal {
     }
 
     function validate() public override {
-        Proxy proxy = Proxy(
+        IProxy proxy = IProxy(
             addresses.getAddress("OPTIMISM_L1_NFT_BRIDGE_PROXY")
         );
 
+        // implementation() caller must be the owner
         vm.startPrank(addresses.getAddress("OPTIMISM_PROXY_ADMIN"));
         require(
             proxy.implementation() ==