Detect UTF-8 BOM symbol with Node.js

index.js

const {open, read} = require('fs/promises');
const {resolve} = require('path');

async function main([filePath]) {
    const resolvedPath = resolve(filePath);
    let file;

    try {
        file = await open(resolvedPath);
    } catch(e) {
        console.error('Couldn\'t opend provided file');
        return;
    }

    const buffer = Buffer.alloc(3);
    const bytes = await file.read(buffer, 0, 3);

    const hasBOM = buffer.toString('utf8')[0] === '\uFEFF';

    if (hasBOM) {
        console.log(`The file at "${resolvedPath}" contains BOM symbol`);
    } else {
        console.log(`The file at "${resolvedPath}" does not contain BOM symbol`);
    }
}

main(process.argv.slice(2));