formdata params , array when length is 1, typeof it is string

Context

• node version: 6.11.1
• multer version: 1.3.0
• environment (node, browser): windows

What are you trying to achieve or the steps to reproduce ?

when I post a array length is 1 , the server accept it as String, but when the legnth > 1, typeof it is Object

Server

var express = require('express');
var path = require('path');
var cookieParser = require('cookie-parser');
var bodyParser = require('body-parser');
var multer = require('multer')

var app = express();

app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: false }));
app.use(multer({ dest: './uploads/'}).any())

app.post('/', function(req, res, next){
  console.log("req.files.length", req.files.length)
  console.log("req.body",req.body)
  a = req.body.a; //the typeof a diffrent with it's length (but I want it as Object)
  console.log("a", typeof(a), a);
  return res.send(req.body || {})
});

// error handler
app.use(function(err, req, res, next) {
  res.status(err.status || 500).send("error" + err);
});

var server = app.listen(3000, function() {
  console.log("web server listening on port " + (server.address().port));
});

Test Demo

var assert = require("chai").assert
var request = require('request')

var url = "http://127.0.0.1:3000/"
describe("post", function(){
  it('array length 1', function(done){
    var opts = {
      method: 'POST',
      url: url,
      formData: {
        b: "hello",
        a: [1]
      }
    };
    request(opts, function(err, res, body){
      assert.equal(null, err);
      console.log("body", body);
      done()
    });
  })

  it('array length 2', function(done){
    var opts = {
      method: 'POST',
      url: url,
      formData: {
        b: "hello",
        a: [1 ,2 , 3]
      }
    };
    request(opts, function(err, res, body){
      assert.equal(null, err);
      console.log("body", body);
      done()
    });
  })
})

the first demo, typeof a is string, but the second a is Object,

[peng-huang-ch]

I am very grateful to you for your advice.

[LinusU]

body-parser doesn’t parse multipart/form-data, are you thinking of the application/x-www-form-urlencoded format? They are quite different, I would advice you to google them to find out how they look 😃