src/macro/index.js
function getShortChunkName (source) {
  if (source.match(relativePkg) || path.isAbsolute(source)) {
    return path.dirname(source).split(path.sep).slice(-2).join('/') + '/' + path.basename(source)
  }
  else {
    return source
  }
}
function getShortChunkName (source) {
  if (source.match(relativePkg) || path.isAbsolute(source)) {
    return path.dirname(source).split(path.sep).slice(-2).join('/') + '/' + path.basename(source)
  }
  else {
    return source
  }
}
function getShortChunkName ( source ) { if ( source . match ( relativePkg ) || path . isAbsolute ( source ) ) { return path . dirname ( source ) . split ( path . sep ) . slice ( - 2 ) . join ( '/' ) + '/' + path . basename ( source ) } else { return source } }
shortens the chunk name to its parent directory basename and its basename
shortens the chunk name to its parent directory basename and its basename