How to post multipart/form-data with node.js superagent

Question

I am trying to send the content-type in my superagent post request to multipart/form-data.

var myagent = superagent.agent();  myagent   .post('http://localhost/endpoint')   .set('api_key', apikey)   .set('Content-Type', 'multipart/form-data')   .send(fields)   .end(function(error, response){     if(error) {         console.log("Error: " + error);     }   }); 

The error I get is: TypeError: Argument must be a string

If I remove the:

.set('Content-Type', 'multipart/form-data') 

I don't get any error but my back end is receiving the request as content-type: application/json

How can I force the content type to be multipart/form-data so that I can access req.files()?

Answer 1

First, you do not mention either of the following:

.set('Content-Type', 'multipart/form-data') 

OR

.type('form') 

Second, you do not use the .send, you use .field(name, value).

Examples

Let's say you wanted to send a form-data request with the following:

• two text fields: name and phone
• one file: photo

So your request will be something like this:

superagent   .post( 'https://example.com/api/foo.bar' )   .set('Authorization', '...')   .accept('application/json')   .field('name', 'My name')   .field('phone', 'My phone')   .attach('photo', 'path/to/photo.gif')    .then((result) => {     // process the result here   })   .catch((err) => {     throw err;   }); 

And, let's say you wanted to send JSON as a value of one of your fields, then you'd do this.

try {   await superagent          .post( 'https://example.com/api/dog.crow' )          .accept('application/json')          .field('data', JSON.stringify({ name: 'value' })) } catch ( ex ) {     // .catch() stuff }  // .then() stuff... 

Answer 2

Try .type('form') instead of .set('Content-Type', 'multipart/form-data')

See http://visionmedia.github.io/superagent/#setting-the-content-type