ALL-9581 - Fix missing decimals function in TRON

Author: Petr Jelínek

src/constants.ts

@@ -274,3 +274,20 @@ export const ZERO_ADDRESS = {
     ZERO_ADDRESS_42_CHARS: '0x0000000000000000000000000000000000000000',
     ZERO_ADDRESS_58_CHARS: '0000000000000000000000000000000000000000000000000000000000',
 }
+
+export const TRON_ABI = [
+  {
+    "constant": true,
+    "inputs": [],
+    "name": "decimals",
+    "outputs": [
+      {
+        "name": "",
+        "type": "uint8"
+      }
+    ],
+    "payable": false,
+    "stateMutability": "View",
+    "type": "Function"
+  }
+];

src/transaction/tron.ts

@@ -2,7 +2,7 @@ import { AxiosRequestConfig } from 'axios';
 import BigNumber from 'bignumber.js';
 import { tronBroadcast } from '../blockchain';
 import { axios, validateBody } from '../connector/tatum';
-import { TATUM_API_URL } from '../constants';
+import { TATUM_API_URL, TRON_ABI } from '../constants'
 import { listing } from '../contracts/marketplace';
 import abi from '../contracts/trc20/token_abi';
 import bytecode from '../contracts/trc20/token_bytecode';
@@ -324,7 +324,7 @@ export const getTronTrc20ContractDecimals = async (testnet: boolean, contractAdd
     }
     const tronWeb = prepareTronWeb(testnet, provider)
     tronWeb.setAddress(contractAddress)
-    const contractInstance = await tronWeb.contract().at(contractAddress)
+    const contractInstance = await tronWeb.contract(TRON_ABI, contractAddress);
     const decimalsBigNum = await contractInstance.decimals().call()
     return new BigNumber(decimalsBigNum).toNumber()
 }