Node-fetch problems with POST requests

Sahand picture Sahand · Apr 15, 2018 · Viewed 33.1k times · Source

In postman, I can successfully make this request:

enter image description here

And get this response:

enter image description here

Now I want to do the same request in my server.js file in node.js:

const fetch = require('node-fetch')
const SEN_URL =  "http://www.sentiment140.com/api/bulkClassifyJson" // URL of sentiment analysis
app.get('/api/sentimenttest', async (req, res) => {
  try{
    var sentiments = await fetch(SEN_URL, {method: "POST", body: {"data": [{"text": "I love you"}, {"text": "I hate you"}]}})
    console.log(sentiments)
    res.send(sentiments)
  }catch(error){
    console.log(error)
  }
})

This doesn't work. Here's what shows up in the browser when I go to localhost:5000/api/sentimenttest:

{"size":0,"timeout":0}

and here's the console output:

 Response {
   size: 0,
   timeout: 0,
   [Symbol(Body internals)]: 
    { body: 
       PassThrough {
         _readableState: [ReadableState],
         readable: true,
         _events: [Object],
         _eventsCount: 2,
         _maxListeners: undefined,
         _writableState: [WritableState],
         writable: false,
         allowHalfOpen: true,
         _transformState: [Object] },
      disturbed: false,
      error: null },
   [Symbol(Response internals)]: 
    { url: 'http://www.sentiment140.com/api/bulkClassifyJson',
      status: 200,
      statusText: 'OK',
      headers: Headers { [Symbol(map)]: [Object] } } }

Since the request works just fine in postman, I think that the problem is with node-fetch, or the way that I use it, specifically how the body parameter is provided in the fetch() call. It seems like the API call does not contain what I want it to, since in the browser it says "size":0.

What should I do to fix this?

Answer

Grynets picture Grynets · Apr 15, 2018

You need to await for json.

var sentiments = await fetch(SEN_URL, {method: "POST", body: {"data": [{"text": "I love you"}, {"text": "I hate you"}]}})
//Here 
await sentiments.json()

Also you can make request with JSON.stringify() for body. And it will be easier to manage your js object. Like this:

var data = {data: [{text: "I love you"}, {text: "I hate you"}]};
var body = JSON.stringify(data);
var sentiments = await fetch(SEN_URL, { method: "POST", body: body });