code: function normalizeDirectives (options) {
    const dirs = options.directives
    if (dirs) {
      for (const key in dirs) {
        const def = dirs[key]
        if (typeof def === 'function') {
          dirs[key] = {bind: def, update: def}
        }
      }
    }
  }
docs: Normalize raw function directives into object format.