I was trying to get some info from a jar file, after that I tried to delete that file (filePath) but I got an error telling I didn't have the required permission, as the file was still running. I'm quite sure it's the fetchJarAtPath method.
const jarFile = await promisify(jarFile.fetchJarAtPath)(filePath);
const mainClass = jarFile.valueForManifestEntry('Main-Class');