eth_getTokenSymbol (#873)

* fix optional blockNumber property in eth_getTransactionCount

* stash

* Tron getBalance implemented

* some code style fixes

* removed TronWeb from dependencies
reworked processTRC20TokenBalanceDetails
added decodeUInt256 method

* some code style fixes

* rolled back yarn.lock

* fixed issue with empty trc20 token balance and with multiply trc20 tokens

* fixed issue with empty trc20 token balance and with multiply trc20 tokens

* fixed code style

* added getTokenSymbol in eth rpc node helpers
fixed decodeUInt256
added decodeHexString

* fix code style

src/dto/rpc/EvmBasedRpcInterface.ts

@@ -131,6 +131,8 @@ export interface EvmBasedRpcInterface {
 
   getTokenDecimals(tokenAddress: string): Promise<JsonRpcResponse<BigNumber>>
 
+  getTokenSymbol(tokenAddress: string): Promise<JsonRpcResponse<string>>
+
   getContractAddress(txHash: string): Promise<string | null>
 
   // web3_ methods

src/service/address/address.ts

@@ -13,7 +13,7 @@ import { CONFIG, Constant, ErrorUtils, ResponseDto, Utils } from '../../util'
 import { EvmRpc, GenericRpc, TronRpc } from '../rpc'
 import { Network, TatumConfig } from '../tatum'
 import { AddressBalance, AddressTransaction, GetAddressTransactionsQuery } from './address.dto'
-import { decodeUInt256 } from '../../util/decode'
+import { decodeHexString, decodeUInt256 } from '../../util/decode';
 
 @Service({
   factory: (data: { id: string }) => {
@@ -124,17 +124,12 @@ export class Address {
     })
   }
 
-  private async processTRC20TokenBalanceDetails(tokenBalances: {[key: string]: string}) {
-    const balances = Object.entries(tokenBalances[0])
-    const serializedTokenBalance: Array<unknown> = []
-    for (let i = 0; i < balances.length; i++) {
-      const asset = await Utils.getRpc<TronRpc>(this.id, this.config).triggerConstantContract(
-        balances[i][0], balances[i][0], 'symbol()', '', { visible: true }
-      ).then(r => decodeUInt256(r.constant_result[0]))
-      const decimals = await Utils.getRpc<TronRpc>(this.id, this.config).triggerConstantContract(
-        balances[i][0], balances[i][0], 'decimals()', '', { visible: true }
-      ).then(r => decodeUInt256(r.constant_result[0]))
-      const balance = balances[i][1]
+  private async processTRC20TokenBalanceDetails(tokenBalances: [{[key: string]: string}]) {
+    const serializedTokenBalance = [];
+    for (let i = 0; i < tokenBalances.length; i++) {
+      const asset = await Utils.getRpc<TronRpc>(this.id, this.config).triggerConstantContract(Object.keys(tokenBalances[i])[0], Object.keys(tokenBalances[i])[0], 'symbol()', '', { visible: true }).then(r => decodeHexString(r.constant_result[0]))
+      const decimals = await Utils.getRpc<TronRpc>(this.id, this.config).triggerConstantContract(Object.keys(tokenBalances[i])[0], Object.keys(tokenBalances[i])[0], 'decimals()', '', { visible: true }).then(r => decodeUInt256(r.constant_result[0]))
+      const balance = Object.values(tokenBalances[i])[0];
       serializedTokenBalance.push({
         asset,
         decimals,
@@ -271,7 +266,7 @@ export class Address {
               key: string,
               value: number,
             }]
-            trc20: {[key: string]: string}
+            trc20: [{[key: string]: string}]
             freeNetLimit: number,
             bandwidth: number,
           }>({
@@ -281,7 +276,7 @@ export class Address {
           {
             return Object.create({
               nativeBalance: r.balance.toString(),
-              tokenBalances: await this.processTRC20TokenBalanceDetails(r.trc20),
+              tokenBalances: r.trc20.length > 0 ? await this.processTRC20TokenBalanceDetails(r.trc20) : [],
             })
           })
     }

src/service/rpc/evm/AbstractEvmRpc.ts

@@ -10,6 +10,7 @@ import {
   TraceType,
   TxPayload,
 } from '../../../dto'
+import { decodeHexString } from '../../../util/decode';
 
 @Service()
 export abstract class AbstractEvmRpc implements EvmBasedRpcInterface {
@@ -150,6 +151,17 @@ export abstract class AbstractEvmRpc implements EvmBasedRpcInterface {
     return response
   }
 
+  async getTokenSymbol(tokenAddress: string): Promise<JsonRpcResponse<string>> {
+    const response = await this.rpcCall<JsonRpcResponse<string>>('eth_call', [
+      { to: tokenAddress, data: '0x95d89b41' },
+      'latest',
+    ])
+    if (response.result) {
+      response.result = decodeHexString(response.result)
+    }
+    return response
+  }
+
   async getContractAddress(txHash: string): Promise<string | null> {
     try {
       const txReceipt = await this.getTransactionReceipt(txHash)

src/util/decode.ts

@@ -1,25 +1,21 @@
-export async function decodeUInt256(uint256Hex: string): Promise<string | number> {
-  const hexString = uint256Hex.replace(/^0+/, '') // Remove leading zeros
-  const byteLength = hexString.length / 2
+export function decodeUInt256(hex: string): number {
+  const formattedHex = hex.replace(/^0x/, '') // Remove 0x
+  return Number('0x' + formattedHex)
+}
+
+export function decodeHexString(hex: string): string {
+  const formattedHex = hex.replace(/^(0x)?0+/, '') // Remove 0x and leading zeros
+  const byteLength = formattedHex.length / 2
   const bytes = []
 
   for (let i = 0; i < byteLength; i++) {
-    const byte = parseInt(hexString.substr(i * 2, 2), 16) // Get the current byte
+    const byte = parseInt(formattedHex.substr(i * 2, 2), 16) // Get the current byte
     bytes.push(byte)
   }
 
-  const firstByte = BigInt(bytes[0]) // Convert the first byte to a BigInt
-  let decodedData
-
-  if (firstByte < BigInt(10)) {
-    // If the first byte is in the range of ASCII digits (0-9), decode as number
-    decodedData = Number('0x' + uint256Hex)
-  } else {
-    decodedData = bytes
-      .map(byte => String.fromCharCode(byte))
-      .filter(char => /[a-zA-Z0-9]/.test(char))
-      .join('')
-  }
-
-  return decodedData
+  return bytes
+    .map(byte => String.fromCharCode(byte))
+    .filter(char => /[a-zA-Z0-9]/.test(char))
+    .join('')
 }
+