Rails forms fix for Firefox auto-complete behaviour (monkey patch)

firefox_autocomplete_related_monkey_patch.rb

# frozen_string_literal: true

# Firefox form fix
module ActionView::Helpers::FormHelper
  alias original_form_for form_for
  def form_for(record, options = {}, &block)
    options[:html] = { autocomplete: 'off' } unless options[:html]
    options[:html][:autocomplete] = 'off' unless options[:html][:autocomplete]

    original_form_for(record, options, &block)
  end

  alias original_form_with form_with
  def form_with(model: nil, scope: nil, url: nil, format: nil, **options, &block)
    options[:html] = { autocomplete: 'off' } unless options[:html]
    options[:html][:autocomplete] = 'off' unless options[:html][:autocomplete]

    original_form_with(**options.merge({model: model, scope: scope, url: url, format: format}), &block)
  end
end

Place file in config/initializers directory.