Fetch post with body data not working params empty

Question

I am trying to rewrite my ajax call to fetch:

Ajax:

  $.post({
    context: this,
    url: "/api/v1/users",
    data: { 
      user: 
        {
          email: email,
          password: password
        } 
    }
  }).done((user) => {
  }).fail((error) => {
  })

Fetch:

  fetch('/api/v1/users', {  
  method: 'POST',
  headers: {
    "Content-Type": "application/json"
  },      
    body: { 
    "user" : 
      {
        "email" : email,
        "password" : password
      } 
  }
  })
  .then(res => {  
    if (res.status !== 200) { {
        console.log("error")
      })          
    } else {
      res.json().then(data => {
        console.log(data)
      })
    }
  })

I am getting an error empty params ~ bad request from my server.

I also found this way to do it, but in this code below I am getting an error: Unexpected token.

  var payload = { 
    "user" : 
      {
        "email" : email,
        "password" : password
      } 
  };

  var data = new FormData();
  data.append( "json", JSON.stringify( payload ) );

  fetch('/api/v1/users', {  
  method: 'POST',
  headers: {
    "Content-Type": "application/json"
  },      
    body: data
  })

How can I rewrite the ajax request to fetch?

Answer 1

Followed this topic on github: https://github.com/matthew-andrews/isomorphic-fetch/issues/34

The solution to my question is using the JSON.stringify function and set Content-Type header to application/json. Not pretty sure why the second attempt in my question didn't work though.

fetch('/api/v1/users', {  
    method: 'post',
    headers: {'Content-Type': 'application/json'},
    body: JSON.stringify({ "user": {
      "email" : email,
      "password" : password
    }}),
})

Official MDN Documentation:

var myHeaders = new Headers();
myHeaders.append('Content-Type', 'application/json');

fetch('/contact-form', {
    method: 'POST',
    headers: myHeaders,
    mode: 'cors',
    cache: 'default',
    body: JSON.stringify(fields)
}).then(() => {
    dispatch(contactFormSubmitSuccess());
});