Parser: `action_view_helpers` doesn't properly convert `[hidden]` for ERB expressions

[marcoroth]

<%= tag.div hidden: a != b do %>
  Content
<% end %>

Gets converted to:

<div hidden="<%= a != b %>">
  Content
</div>

I think it would have to be something like this, since only the presence of hidden is relevant.

<div <% if a != b %> hidden <% end %>>
  Content
</div>

There are probably a few more boolean attributes, like required, selected and similar. Though. the follow converts properly:

<%= tag.div hidden: true do %>
  Content
<% end %>

<%= tag.div hidden: false do %>
  Content
<% end %>

to

<div hidden>
  Content
</div>

<div>
  Content
</div>