Node.js - generate multipart/form-data

fermata looks like it might be what you're looking for. From the github page:

fermata.json("http://example.com/some/action").post({
  'Content-Type':"multipart/form-data"
}, {
  fileField: form.input.file || {data:nodeBuffer, name:"", type:""}
}, callback)

request supports multipart/form-data or if you're just looking to create the content body, try form-data

I know this is old but I recently needed to generate a form's multipart/form-data body string and came across this thread.

I was unable to find any modules out there that did this in a simple way so I made my own module: https://github.com/kodie/form-data-body

You can use it like so:

const formDataBody = require('form-data-body')

// Specify form fields
const fields = {
  name: 'My test post',
  description: 'This is just a test post',
  items: ['First Item', 'Second Item'],

  // Files should be an object with the name, type, and data set to strings
  image: {
    name: 'hello.jpg',
    type: 'image/jpeg',
    data: binaryImageData
  }
}

const boundary = formDataBody.generateBoundary()
const header = {
  'Content-Type': `multipart/form-data; boundary=${boundary}`
}
const body = formDataBody(fields, boundary)

Example Output:

----------------------------071517909670537006900435
Content-Disposition: form-data; name="name"

My test post
----------------------------071517909670537006900435
Content-Disposition: form-data; name="description"

This is just a test post
----------------------------071517909670537006900435
Content-Disposition: form-data; name="items[]"

First Item
----------------------------071517909670537006900435
Content-Disposition: form-data; name="items[]"

Second Item
----------------------------071517909670537006900435
Content-Disposition: form-data; name="image"; filename="hello.jpg"
Content-Type: image/jpeg

[BINARY IMAGE DATA]
----------------------------071517909670537006900435--