Node JS testing - mock file upload

Question

I'm using node-mocks-http to test my API and I have problems simulating a file upload. Here is my attempt:

var response = buildResponse()
var request  = http_mocks.createRequest({
  method: 'POST',
  url    : '/test',
  headers: {
    'Content-Type'     : 'multipart/form-data;',
    'Transfer-Encoding': 'identity'
  },
  files: {
    project: fs.createReadStream('tests/fixtures/test.json')
  }
})

response.on('end', function() {
  response._getData().should.equal('finished');
  done();
})

app.handle(request, response)

Any idea why that wouldn't lead to a proper file upload? At least, the express-fileupload module is not seeing it as one.

Many thanks.

Answer 1

I'm not directly addressing node-mocks-http, but I use supertest to mock file uploads in Node.js testing to achieve the same goal.

In my case, my Express middleware use Formidable to parse form data, especially file uploads; supertest works really well with Formidable.

Below is a piece of code sample. It tests my Express middleware, which uploads a file to an Minio S3 bucket.

it('posts a file', done => {
  const app = express()
  app.post(
    '/api/upload',
    minioMiddleware({ op: expressMinio.Ops.post }),
    (req, res) => {
      if (req.minio.error) {
        res.status(400).json({ error: req.minio.error })
      } else {
        res.send(`${req.minio.post.filename}`)
      }
    }
  )

  request(app)
    .post('/api/upload')
    .attach('file', '/tmp/a-file-to-upload.txt')
    .expect(200, done)
})

supertest in this test will upload the file /tmp/a-file-to-upload.txt and the Middleware will in turn put the file in Minio S3. It works well for me.