How to deal with Chinese garbled code in nodejs json

Per "fs.readFileSync(filename, 'utf8') doesn't strip BOM markers #1918", fs.readFile is
working as designed: BOM is not stripped from the header of the UTF-8 file, if it exists. It at the discretion of the developer to handle this.
Possible workarounds:
data= data.replace(/^\uFEFF/, ''); perhttps://github.com/joyent/node/issues/1918#issuecomment-2480359
Transform the incoming stream to remove the BOM header with the NPM module bomstrip perhttps://github.com/joyent/node/issues/1918#issuecomment-38491548
What you are getting is the byte order mark header (BOM) of the UTF-8 file. When JSON.parse sees
this, it gives an syntax error (read: "unexpected character" error). You must strip the byte order mark from the file before passing it to JSON.parse:

fs.readFile('./myconfig.json', 'utf8', function (err, data) {
  myconfig = JSON.parse(data.toString('utf8').replace(/^\uFEFF/, ''));
});
// note: data is an instance of Buffer

// 参数file，必须保存为utf8格式，否则里面的中文会乱码  
function readFile(file){  
    // readFile的第2个参数表示读取编码格式，如果未传递这个参数，表示返回Buffer字节数组  
    fs.readFile(file, "utf8", function(err, data){  
        if(err)  
            console.log("读取文件fail " + err);  
        else{  
            // 读取成功时  
            console.log(data);// 直接输出中文字符串了  
        }  
    });  
}

var iconv = require('iconv-lite');  
   
var fs = require('fs');  
var fileStr = fs.readFileSync('D:\\test.csv', {encoding:'binary'});  
   
var buf = new Buffer(fileStr, 'binary');  
   
var str = iconv.decode(buf, 'GBK');  
console.log(str);