I am running a server in which users get a javascript file when they sign up. They can use this on their website, and I can track it.

So people register through my expressjs project, but to change the JS file they will receive, i use this code.

    if (checkExists[0]['COUNT(1)'] == 1n) {
        const options = {
            files: 'src/sdk.js',
            from: 'var Hh="-4534939823",',
            to: `var Hh="${chatId}",`,
          }
        fs.copyFile('theFile.js', 'src/sdk.js', (err) => { //copy file to
            if (err) throw err;
          });

        try { //replace chatID
            const result = await replaceInFile(options)
            console.log(result)
        }
        catch (error) {
          console.error(error)
        }
        child_process.execSync(`zip -r src.zip src`);
  
        a.finally(() => {
            child_process.exec('rm src/sdk.js; rm src.zip')
        })
    }

So i create a duplicate of the original -> edit lines -> zip the file -> send it back
I have a big feeling that this will fail over time. Is there a standard way / package in Node for such tasks?

it works, but is it optimal?