feat: Add delimiter to referrer tag (#154)

* feat: Add delimiter to referrer tag

To make it easier for clients to identify referred transactions, add a delimitter in front of referrer address. By adding in front, this allows referrer-identification logic to be backwards compatible

* Make delimitter optional

* Spelling delimiter

* change delimiter value

* Update constants.ts

* fix

Signed-off-by: nicholaspai <npai.nyc@gmail.com>

src/utils/bridge.ts

@@ -19,6 +19,7 @@ import {
   queriesTable,
   FLAT_RELAY_CAPITAL_FEE,
   relayerFeeCapitalCostConfig,
+  referrerDelimiterHex,
 } from "./constants";
 
 import { parseEther, tagAddress } from "./format";
@@ -237,7 +238,7 @@ export async function sendAcrossDeposit(
   // do not tag a referrer if data is not provided as a hex string.
   tx.data =
     referrer && ethers.utils.isAddress(referrer)
-      ? tagAddress(tx.data!, referrer)
+      ? tagAddress(tx.data!, referrer, referrerDelimiterHex)
       : tx.data;
 
   return signer.sendTransaction(tx);

src/utils/constants.ts

@@ -677,3 +677,5 @@ const getQueriesTable = () => {
 };
 
 export const queriesTable = getQueriesTable();
+
+export const referrerDelimiterHex = "0xd00dfeeddeadbeef";

src/utils/format.ts

@@ -86,9 +86,13 @@ export function stringToHex(value: string) {
 }
 
 // appends hex tag to data
-export function tagHex(dataHex: string, tagHex: string) {
+export function tagHex(
+  dataHex: string,
+  tagHex: string,
+  delimitterHex: string = ""
+) {
   assert(ethers.utils.isHexString(dataHex), "Data must be valid hex string");
-  return ethers.utils.hexConcat([dataHex, tagHex]);
+  return ethers.utils.hexConcat([dataHex, delimitterHex, tagHex]);
 }
 
 // converts a string tag to hex and appends, currently not in use
@@ -97,9 +101,13 @@ export function tagString(dataHex: string, tagString: string) {
 }
 
 // tags only an address
-export function tagAddress(dataHex: string, address: string) {
+export function tagAddress(
+  dataHex: string,
+  address: string,
+  delimiterHex: string = ""
+) {
   assert(ethers.utils.isAddress(address), "Data must be a valid address");
-  return tagHex(dataHex, address);
+  return tagHex(dataHex, address, delimiterHex);
 }
 
 export function capitalizeFirstLetter(str: string) {