image.test.js

const request = require('supertest')
const app = require('../app')

test('image passes through successfully', async () => {
  await request(app)
    .post('/products')
    .attach('image', 'tests/images/dog.jpg')
    .field('name', 'harrison')
    .then((response) => {
      console.log(response.text)
      expect(response.text).toBeTruthy()
    })
})

multer-middleware.js

const multer = require('multer')

const storage = multer.memoryStorage()
const upload = multer({storage: storage })

const form = [
  {name: 'name'},
  {name: 'image'}
]

module.exports = upload.fields(form)

products-controller.js

const index = (req, res) => {
  const { image } = req.files
  const { name } = req.body
  console.log(name)
  console.log(image[0])
  // s3 stuff
  // handling the file buffer
  res.send('api works')  
}

module.exports = {
  index,
}

products.js

const express = require('express')
const router = express.Router()

const multer = require('../middleware/multer-middleware') 

const { index } = require('../controllers/products-controller')

router.post('/', multer, index)

module.exports = router