module-details-from-path/index.js

Resolve npm package details, like name and base path, given an absolute path to a file inside a package

'use strict'

var sep = require('path').sep

module.exports = function (file) {
  var segments = file.split(sep)
  var index = segments.lastIndexOf('node_modules')

  if (index === -1) return
  if (!segments[index + 1]) return

  var scoped = segments[index + 1][0] === '@'
  var name = scoped ? segments[index + 1] + '/' + segments[index + 2] : segments[index + 1]
  var offset = scoped ? 3 : 2

  var basedir = ''
  var lastBaseDirSegmentIndex = index + offset - 1
  for (var i = 0; i <= lastBaseDirSegmentIndex; i++) {
    if (i === lastBaseDirSegmentIndex) {
      basedir += segments[i]
    } else {
      basedir += segments[i] + sep
    }
  }

  var path = ''
  var lastSegmentIndex = segments.length - 1
  for (var i2 = index + offset; i2 <= lastSegmentIndex; i2++) {
    if (i2 === lastSegmentIndex) {
      path += segments[i2]
    } else {
      path += segments[i2] + sep
    }
  }

  return {
    name: name,
    basedir: basedir,
    path: path
  }
}