cli: query token decimals outside of forge script

This works around and edge case when the token contract is compiled
against a different EVM version than what the forge script is running
in (london currently).

Author: kcsongor

cli/src/index.ts

@@ -31,6 +31,7 @@ import type { EvmNtt, EvmNttWormholeTranceiver } from "@wormhole-foundation/sdk-
 import type { EvmChains } from "@wormhole-foundation/sdk-evm";
 import { getAvailableVersions, getGitTagName } from "./tag";
 import * as configuration from "./configuration";
+import { ethers } from "ethers";
 
 // TODO: contract upgrades on solana
 // TODO: set special relaying?
@@ -947,8 +948,13 @@ async function deployEvm<N extends Network, C extends Chain>(
     const rpc = ch.config.rpc;
     const specialRelayer = "0x63BE47835c7D66c4aA5B2C688Dc6ed9771c94C74"; // TODO: how to configure this?
 
+    const provider = new ethers.JsonRpcProvider(rpc);
+    const abi = ["function decimals() external view returns (uint8)"];
+    const tokenContract = new ethers.Contract(token, abi, provider);
+    const decimals: number = await tokenContract.decimals();
+
     // TODO: should actually make these ENV variables.
-    const sig = "run(address,address,address,address,uint8)";
+    const sig = "run(address,address,address,address,uint8,uint8)";
     const modeUint = mode === "locking" ? 0 : 1;
     const signer = await getSigner(ch, signerType);
     const signerArgs = forgeSignerArgs(signer.source);
@@ -975,7 +981,7 @@ async function deployEvm<N extends Network, C extends Chain>(
             execSync(`
 forge script --via-ir script/DeployWormholeNtt.s.sol \
 --rpc-url ${rpc} \
---sig "${sig}" ${wormhole} ${token} ${relayer} ${specialRelayer} ${modeUint} \
+--sig "${sig}" ${wormhole} ${token} ${relayer} ${specialRelayer} ${decimals} ${modeUint} \
 --broadcast ${verifyArgs.join(' ')} ${signerArgs} | tee last-run.stdout`, {
                 cwd: `${pwd}/evm`,
                 encoding: 'utf8',

evm/script/DeployWormholeNtt.s.sol

@@ -19,24 +19,36 @@ contract DeployWormholeNtt is Script, DeployWormholeNttBase {
         address token,
         address wormholeRelayer,
         address specialRelayer,
+        uint8 decimals,
         IManagerBase.Mode mode
     ) public {
         vm.startBroadcast();
 
         console.log("Deploying Wormhole Ntt...");
         IWormhole wh = IWormhole(wormhole);
 
+        // sanity check decimals
         (bool success, bytes memory queriedDecimals) =
             token.staticcall(abi.encodeWithSignature("decimals()"));
 
-        if (!success) {
-            console.log("Failed to query token decimals");
-            vm.stopBroadcast();
-            return;
+        if (success) {
+            uint8 queriedDecimals = abi.decode(queriedDecimals, (uint8));
+            if (queriedDecimals != decimals) {
+                console.log("Decimals mismatch: ", queriedDecimals, " != ", decimals);
+                vm.stopBroadcast();
+                return;
+            }
+        } else {
+            // NOTE: this might not be a critical error. It could just mean that
+            // the token contract was compiled against a different EVM version than what the forge script is running on.
+            // In this case, it's the responsibility of the caller to ensure that the provided decimals are correct
+            // and that the token contract is valid.
+            // The best way to ensure that is by calling this script with the queried token decimals (which is what the NTT CLI does).
+            console.log(
+                "Failed to query token decimals. Proceeding with provided decimals.", decimals
+            );
         }
 
-        uint8 decimals = abi.decode(queriedDecimals, (uint8));
-
         uint16 chainId = wh.chainId();
 
         console.log("Chain ID: ", chainId);