src/fs.js
function readFileSync(filename, cache, encoding=null) {
  if (cache.has(filename) && (cache.get(filename) !== true)) return cache.get(filename);
  const data = fs.readFileSync(filename, encoding);
  cache.set(filename, data);
  return data;
}
function readFileSync(filename, cache, encoding=null) {
  if (cache.has(filename) && (cache.get(filename) !== true)) return cache.get(filename);
  const data = fs.readFileSync(filename, encoding);
  cache.set(filename, data);
  return data;
}
function readFileSync ( filename , cache , encoding = null ) { if ( cache . has ( filename ) && ( cache . get ( filename ) !== true ) ) return cache . get ( filename ) ; const data = fs . readFileSync ( filename , encoding ) ; cache . set ( filename , data ) ; return data ; }
Read a file synchronously using file cache.

@param {string} filename               The filename to load.
@param {Map} cache                     The cache to use.
@param {null|strin} [encoding=null]    The encoding to use.
@returns {Buffer\*}                    The file contents as a buffer.
Read a file synchronously using file cache .