path.replace is not a function

[elixiao]

代码：

const formstream = require('formstream')
const fs = require('fs')
const path = require('path')
const filepath = path.join(__dirname, '1.jpg')
const file = fs.createReadStream(filepath)

const stream = formstream()
stream.file('uri', file)
stream.field('hello', 'world')
console.log(stream)

报错：

  var ext = path.replace(/^.*[\.\/\\]/, '').toLowerCase();
                 ^

TypeError: path.replace is not a function
 at Mime.lookup (/project/node_modules/mime/mime.js:70:18)
    at FormStream.file (/project/node_modules/formstream/lib/formstream.js:113:23)
    at Object.<anonymous> (/project/form-data.js:35:8)
    at Module._compile (internal/modules/cjs/loader.js:776:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:787:10)
    at Module.load (internal/modules/cjs/loader.js:653:32)
    at tryModuleLoad (internal/modules/cjs/loader.js:593:12)
    at Function.Module._load (internal/modules/cjs/loader.js:585:3)
    at Function.Module.runMain (internal/modules/cjs/loader.js:829:12)

[elixiao]

use the following syntax solves the problem:

stream.stream('uri', file, '1.jpg')