USDC related changes

packages/cli/src/base.ts

@@ -206,6 +206,7 @@ export abstract class BaseCommand extends Command {
       : getGasCurrency(this.config.configDir)
 
     const setStableTokenGas = async (stable: StableToken) => {
+      // TODO(Arthur): Update implementation to match new `setFeeCurrency` method signature
       await kit.setFeeCurrency(stableTokenInfos[stable].contract)
     }
     if (Object.keys(StableToken).includes(gasCurrencyConfig)) {

packages/cli/src/transfer-stable-base.ts

@@ -38,6 +38,7 @@ export abstract class TransferStableBase extends BaseCommand {
     }
     // If gasCurrency is not set, use the transferring token
     if (!res.flags.gasCurrency) {
+      // TODO(Arthur): Update implementation to match new `setFeeCurrency` method signature
       await kit.setFeeCurrency(stableTokenInfos[this._stableCurrency].contract)
     }
 

packages/sdk/connect/src/connection.ts

@@ -131,6 +131,7 @@ export class Connection {
    *
    * @param address ERC20 address
    */
+  // TODO(Arthur): Consider replacing `Address` with stronger type like `StrongAddress`
   set defaultFeeCurrency(address: Address | undefined) {
     this.config.feeCurrency = address
   }

packages/sdk/contractkit/README.md

@@ -80,7 +80,8 @@ async function getKit(myAddress: string, privateKey: string) {
   kit.connection.addAccount(privateKey)
 
   // paid gas in celo dollars
-  await kit.setFeeCurrency(CeloContract.StableToken)
+  // TODO(Arthur): Update this example when the method signature for `setFeeCurrency` is confirmed.
+  await kit.setFeeCurrency(CeloContract.StableToken) 
 
   return kit
 }
@@ -117,7 +118,7 @@ const receipt = await tx.waitReceipt()
 If you would like to pay fees in cUSD, (or other cStables like cEUR, cUSD).
 
 ```ts
-
+// TODO(Arthur): Update this example when the method signature for `setFeeCurrency` is confirmed.
 kit.setFeeCurrency(CeloContract.StableToken) // Default to paying fees in cUSD
 
 const stableTokenContract = kit.contracts.getStableToken()

packages/sdk/contractkit/src/kit.ts

@@ -190,6 +190,7 @@ export class ContractKit {
   /**
    * Set an addressed to use to pay for gas fees
    * @param address any hexadecimal address
+   * @dev Throws if supplied address is not a valid hexadecimal address
    */
   setFeeCurrency(address: StrongAddress) {
     if (!isHexString(address)) {