All data persistence logic without fs.readFileSync code example

Example 1: node read file sync

// macOS, Linux, and Windows
fs.readFileSync('<directory>');
// => [Error: EISDIR: illegal operation on a directory, read <directory>]

//  FreeBSD
fs.readFileSync('<directory>'); // => <data>

Example 2: fs readfile encoding

fs.readFile('/etc/passwd', 'utf8', callback);