WIP

src/clients/bridges/ArbitrumAdapter.ts

@@ -195,17 +195,25 @@ export class ArbitrumAdapter extends BaseAdapter {
     );
   }
 
-  async wrapEthIfAboveThreshold(threshold: BigNumber, simMode = false): Promise<TransactionResponse | null> {
+  // The arbitrum relayer expects to receive ETH steadily per HubPool bundle processed, since it is the L2 refund
+  // address hardcoded in the Arbitrum Adapter. Therefore, to avoid excessively wrapping ETH, we only wrap
+  // it once it gets above a certain threshold.
+  async wrapEthIfAboveThreshold(target: BigNumber, simMode = false): Promise<TransactionResponse | null> {
     const { chainId } = this;
     assert(42161 === chainId, `chainId ${chainId} is not supported`);
 
     const weth = CONTRACT_ADDRESSES[this.chainId].weth;
     const ethBalance = await this.getSigner(chainId).getBalance();
+
+    // For Arbitrum specifically, ETH should accumulate steadily. So reduce ETH balance down to the target
+    // if it exceeds a threshold.
+    // TODO: Add a configurable ETH target as opposed to just a threshold.
+    const threshold = target.mul(10);
     if (ethBalance.gt(threshold)) {
       const l2Signer = this.getSigner(chainId);
       const contract = new Contract(weth.address, weth.abi, l2Signer);
-      const value = ethBalance.sub(threshold);
-      this.logger.debug({ at: this.getName(), message: "Wrapping ETH", threshold, value, ethBalance });
+      const value = ethBalance.sub(target);
+      this.logger.debug({ at: this.getName(), message: "Wrapping ETH", threshold, target, value, ethBalance });
       return await this._wrapEthIfAboveThreshold(threshold, contract, value, simMode);
     }
     return null;

src/clients/bridges/BaseAdapter.ts

@@ -325,9 +325,13 @@ export abstract class BaseAdapter {
     const { chainId, txnClient } = this;
     const method = "deposit";
     const mrkdwn =
-      `Ether on chain ${this.chainId} was wrapped due to being over the threshold of ` +
+      `${createFormatFunction(2, 4, false, 18)(toBN(value).toString())} Ether on chain ${
+        this.chainId
+      } was wrapped due to being over the threshold of ` +
       `${createFormatFunction(2, 4, false, 18)(toBN(wrapThreshold).toString())} ETH.`;
-    const message = `Eth wrapped on target chain ${this.chainId}🎁`;
+    const message = `${createFormatFunction(2, 4, false, 18)(toBN(value).toString())} Eth wrapped on target chain ${
+      this.chainId
+    }🎁`;
     if (simMode) {
       const { succeed, reason } = (
         await txnClient.simulate([{ contract: l2WEthContract, chainId, method, args: [], value, mrkdwn, message }])