why is fs.readFile returning void in node.js

February 9, 2023

I’m new to node,js,typescript and NPM as a whole, I need a certain funtionality in a discord bot I’m building and only sdk I found to get it is in typescript which is a whole new world for me,
I’m trying to read a file using fs.readFile
here is the code:

import { readFile } from "fs";
import { Connection, Keypair } from "@solana/web3.js";
import { getOrca, OrcaFarmConfig, OrcaPoolConfig } from "@orca-so/sdk";
import Decimal from "decimal.js";

//console.log('test');
const main = async() => {
    const secretKeyString = readFile("lp.json", (error, data) => data);
    const secretKey = Uint8Array.from(JSON.parse(secretKeyString));
    const owner = Keypair.fromSecretKey(secretKey);
}

I’m getting a problem:

Argument of type 'void' is not assignable to parameter of type 'string'.

ik that the function is async but I’m not familliar with asyncio in javascript so how can I resolve this?

>Solution :

You should use readFileSync here as it will serve the purpose you need in that context.

import { readFile } from "fs";
import { Connection, Keypair } from "@solana/web3.js";
import { getOrca, OrcaFarmConfig, OrcaPoolConfig } from "@orca-so/sdk";
import Decimal from "decimal.js";

//console.log('test');
const main = async() => {
    const secretKeyString = readFileSync("lp.json", {
        encoding: "utf-8",
    });
    const secretKey = Uint8Array.from(JSON.parse(secretKeyString));
    const owner = Keypair.fromSecretKey(secretKey);
}