Snippet to fill out the form at https://react-form.herokuapp.com

contact-form.js

document.getElementsByName('name')[0].value = 'name';
document.getElementsByName('email')[0].value = 'test@example.com';
document.getElementsByName('company')[0].value = 'company';
document.getElementsByName('phone')[0].value = '1234';
document.getElementsByName('website')[0].value = 'https://www.lullabot.com';
document.getElementsByName('areas')[2].checked = 'checked';
document.getElementsByName('areas')[0].checked = 'checked';
document.getElementsByName('when')[4].checked = 'checked';
document.getElementsByName('budget')[0].value = 'budget';
document.getElementsByName('project')[0].innerHTML = 'project';
document.getElementsByName('referal')[0].value = 'friend';