Rails 5.1.2:

I'm trying to create an AJAX form using [form\_with](http://api.rubyonrails.org/v5.1/classes/ActionView/Helpers/FormHelper.html#method-i-form_with) in line with the [Rails documentation](http://guides.rubyonrails.org/working_with_javascript_in_rails.html#built-in-helpers) and [this GitHub thread](https://github.com/rails/rails/issues/25197).

This code:

```
<%= form_with url: '/' do |f| %>
<% end %>

```

and in fact this code:

```
<%= form_with url: '/', remote: true do |f| %>
<% end %>

```

both produce this html:

```
<form action="/" accept-charset="UTF-8" method="post">
  <input name="utf8" type="hidden" value="..." />
  <input type="hidden" name="authenticity_token" value="..." />
</form>

```

Why isn't `data-remote="true"` appearing in the HTML, as the first link I have posted indicates it should, and how do I get it to appear?