Trying to post multipart/form-data with node.js supertest

Question

I was trying to use Node.js supertest to test some REST API I had written. I need to send a request equivalent to the following CURL request:

curl -X POST -F api_key=KEY -F image=@my_file http://localhost:3000/v1/upload

I tried the following, but I got Uncaught TypeError: first argument must be a string or Buffer.

request.post('/v1/upload')
.type('form')
.field('api_key', 'abcd')
.attach('image', 'some path')
.end(function(err, res) {
  res.body.error.should.equal('Invalid username/api_key.');
  done();
});

I also tried sending it as this:

request.post('/v1/upload')
.type('form')
.field('api_key', 'abcd')
.attach('image', 'some path')
.end(function(err, res) {
  res.body.error.should.equal('Invalid username/api_key.');
  done();
});

but the server can only parse the file upload request and not the api_key.

Answer 1

Try removing .type('form') from your tests, because it will set application/x-www-form-urlencoded as Content-Type, instead of multipart/form-data.