ajax的params,jquery ajax post with params

I need to upload file using JQuery's $ajax function, besides uploading the file, i want be able to tell which folder/directory this filed uploaded to. i tried the following but it won't work:

data = new FormData()

data.append('csv', fileData)

$.ajax

cache: false

contentType:false

processData: false

type: 'POST'

dataType: 'script'

url: '/api/upload/'

params: ['test']

data: data

complete: (res) =>

if not (res.status is 200)

console.log(res.responseText)

return false

else

return true

the api worked fine, but when check the request it always showed the params as empty:

params: []

query: {}

how can i pass extra parameter to ajax post? thanks