Do not require a Signer for contract.populateTransaction.

Author: ricmoo

packages/contracts/src.ts/index.ts

@@ -218,12 +218,12 @@ function runMethod(contract: Contract, functionName: string, options: RunOptions
                 })
             }
 
+            if (options.transaction) { return resolveProperties(tx); }
+
             if (!contract.signer) {
                 errors.throwError("sending a transaction require a signer", errors.UNSUPPORTED_OPERATION, { operation: "sendTransaction" })
             }
 
-            if (options.transaction) { return resolveProperties(tx); }
-
             return contract.signer.sendTransaction(tx).then((tx) => {
                 let wait = tx.wait.bind(tx);