code: function resolveComponent (file) {
    // make sure relative paths resolved to somewhere inside veui
    let pkg = pkgDir.sync(file)
    if (!pkg || getJSON(path.join(pkg, 'package.json')).name !== 'veui') {
      return null
    }
  
    // veui/${dir} or veui/src/${dir}
    let dirPath = path.join(pkg, COMPONENTS_DIRNAME) // runtime
    if (!fs.existsSync(dirPath)) {
      dirPath = path.join(pkg, 'src', COMPONENTS_DIRNAME) // dev
      if (!fs.existsSync(dirPath)) {
        return null
      }
    }
  
    // is VEUI component
    return getComponentName(path.relative(dirPath, file))
  }
docs: Resolve the underlying component for a given file path.
  '/dev/veui/src/components/Button.vue' → 'Button'
  @param {string} file Absolute file path
  @returns {?string} The resolved component name (`null` if not a VEUI component)