node-fetch-form-data.js

const fetch = require('node-fetch');
const FormData = require('form-data');
const nock = require('../');

const formData = new FormData();
formData.append('test', 'true');

nock('http://localhost')
    .post('/api/test')
    .reply(function(uri, requestBody) {
        console.log(typeof requestBody, requestBody);
    });

fetch('http://localhost/api/test', {method: 'POST', body: formData});