nodejs读取并去重excel文件

/**
 * 安装node-xlsx插件
 */
var path = require('path')
var fs = require('fs')
var xlsx = require('node-xlsx')

//去重算法
Array.prototype.unique = function () {
 this.sort(); //先排序
 var res = [this[0]];
 for (var i = 1; i < this.length; i++) {
  if (this[i] !== res[res.length - 1]) {
   res.push(this[i]);
  }
 }
 return res;
}

//取得xlsx
var obj = xlsx.parse(path.resolve(`./xlsx/x.xlsx`))
var newArray = []

//读取第一列
//obj[0].data:指第一个sheet的表格数据
//data内部的数据结构为：
//[[ 'field1','field2','field13' ],[ 'field1','field2','field13' ]]
for (var data of obj[0].data) {
 newArray.push(data[0])
}
//去重之前
console.log(newArray.length)
var openIds = newArray.unique();
//去重之后
console.log(newArray.length)

var j = 0
for (var i = 0; i < newArray.length; i++) {
 //每一行
 console.log(newArray[i])
}

//json结构 
[{
 name: 'sheet1 name',
 data: [['field1', 'field2', 'field13'],
  ['field1', 'field2', 'field13']]
},
 {
  name: 'sheet2 name',
  data: [['field1', 'field2', 'field13'],
   ['field1', 'field2', 'field13']]
 }]