Multiple inputs with the same name generate unparseable names in Rails >= 7.1.1

[nduitz]

Environment

• Ruby 3.3.0
• Rails 7.1.3
• Simple Form 5.3.0

Hey, there.

Rack changed how they parse query parameters which causes the usage of multiple inputs of the same name to generate unparseable query parameters.

Here is a quick example:

<%= simple_form_for :foo do |f| %>
  <%= f.input 'bar[][id]' %>
  <%= f.input 'bar[][id]' %>
  <%= f.input 'bar[][id]' %>
  <%= f.input 'bar[][id]' %>
<% end %>

The use case here is to create parameters that contain an array in bar which consists of hashes containing id keys.

Current behavior

This produces inputs with names like this: foo[bar[][id]] which is no longer supported by rack see rack/rack#2128

The resulting parameters look like this:

"foo"=>{"bar["=>{"id"=>{"]"=>"33"}}}

Maybe this is not the intended way to create query params that contain an array containing hashes?
I tried using simple_fields_for but I could not make it work

Expected behavior

I think the names generated by a form like this should follow the conventions mentioned by rails: https://guides.rubyonrails.org/form_helpers.html#understanding-parameter-naming-conventions

thus generating names like this:

foo[bar][][id]

Current Workaround

Simply setting the name manually by adding input_html: { name: '...' }

BTW:

If anyone could point out where this is implemented I am happy to create a PR but I currently don't have the time to dig this myself.