Best practices for transaction management

erc20TransferFrom.ts

const erc20TransferFrom = async () => {
  try {
    /* ---------------------------- SETUP ------------------------------ */

    /* 
    USING INFURA PROVIDER
    */
    const provider: ethers.providers.InfuraProvider =
      new ethers.providers.InfuraProvider('maticmum', infuraProjectID);

    /* 
    INITIALIZE SIGNER 
    */
    const signer: ethers.Wallet = new ethers.Wallet(privateKey, provider);

    /*
      GET SIGNER NONCE
    */
    const nonce: number = await provider.getTransactionCount(signer.address);

    /* 
      FETCH THE FAST LATEST GAS PRICE DATA FROM THE POLYGON V2 gas station API
    */
    const {maxFee, maxPriorityFee}: GasData = await fetchGasPrice();

    /* ---------------------------- FUNCTION CALL ---------------------------- */

    /* 
      INITIALIZE TESTERC20 INSTANCE AND CONNECT WITH SIGNER
    */
    const testERC20Instance: ethers.Contract = new ethers.Contract(
      address,
      abi,
      provider
    );
    const testERC721: ethers.Contract = testERC20Instance.connect(signer);

    /*
      ESTIMATE GAS
    */
    const estimatedGasLimit: ethers.BigNumber =
      await testERC20.estimateGas.transferFrom(fromAddress, toAddress, amount, {
        gasLimit: 14_999_999,
        nonce: nonce,
        maxFeePerGas: maxFee,
        maxPriorityFeePerGas: maxPriorityFee,
      });

    /*
      TRANSFERFROM
    */
    const response: ethers.ContractTransaction =
      await testERC20.transferFrom(fromAddress, toAddress, amount, {
        gasLimit: estimatedGasLimit,
        nonce: nonce,
        maxFeePerGas: maxFee,
        maxPriorityFeePerGas: maxPriorityFee,
      });
    await response.wait(15);  // wait for 15 block confirmation
    const txReceipt: ethers.providers.TransactionReceipt =
      await provider.getTransactionReceipt(response.hash);
    }
  } catch (error) {
    console.log('Error in erc20TransferFrom', error);
    process.exit(1);
  }
}

issueToken()
  .then(() => {
    console.log('\n\n---------- ENDING ALL PROCESS ----------\n\n');
    process.exit(0);
  })
  .catch((error) => {
    console.error('error', error);
    process.exit(1);
  });

fetchGasPrice.ts

export async function fetchGasPrice(): Promise<GasData> {
  try {
    const response: Response = await fetch(
      'https://gasstation-testnet.polygon.technology/v2'
    );

    const gasData: GasApiResponse = await response.json(); // Extract JSON data from the response

    // Get the maxFee and maxPriorityFee for fast
    const maxFeeInGWEI = gasData.fast.maxFee;
    const maxPriorityFeeInGWEI = gasData.fast.maxPriorityFee;

    /* Convert the fetched GWEI gas price to WEI after converting ignore the decimal value
     * as the transaction payload only accepts whole number
     */
    const maxFee = Math.trunc(maxFeeInGWEI * 10 ** 9);
    const maxPriorityFee = Math.trunc(maxPriorityFeeInGWEI * 10 ** 9);
    return {maxFee, maxPriorityFee};
  } catch (error) {
    console.log(`Error in fetchGasPrice: ${error}`);
    process.exit(1);
  }
}