```ruby
module DynamicPaperclip
  class Attachment < Paperclip::Attachment
    attr_reader :dynamic_styles

    def initialize(name, instance, options = {})
      super

      @dynamic_styles = {}

      # Add existing dynamic styles
      if instance.persisted?
        path_with_wildcard = path('dynamic_*')
        style_position = path_with_wildcard.index('dynamic_*')

        Dir.glob(path_with_wildcard) do |file|
          add_dynamic_style! file[style_position..-1].split('/').first
        end
      end
    end

    def styles
      super.merge dynamic_styles
    end

    def process_dynamic_style(style_name)
      add_dynamic_style! style_name
      reprocess! style_name
    end

    def dynamic_url(definition)
      raise DynamicPaperclip::Errors::SecretNotSet, "No secret has been configured. Please run the dynamic_paperclip:install generator." unless DynamicPaperclip.config.secret.present?

      style_name = StyleNaming.dynamic_style_name_from_definition(definition)

      url = url(style_name)

      delimiter_char = url.match(/\?.+=/) ? '&' : '?'

      "#{url}#{delimiter_char}s=#{UrlSecurity.generate_hash(style_name)}"
    end

    private

      def add_dynamic_style!(name)
        @dynamic_styles[name.to_sym] = Paperclip::Style.new(name, StyleNaming.style_definition_from_dynamic_style_name(name), self)
      end
  end
end```

Fix extraction of existing dynamic styles from FS when style name is used as the file name
user
```ruby
module DynamicPaperclip
  class Attachment < Paperclip::Attachment
    attr_reader :dynamic_styles

    def initialize(name, instance, options = {})
      super

      @dynamic_styles = {}

      # Add existing dynamic styles
      if instance.persisted?
        path_with_wildcard = path('dynamic_*')
        style_position = path_with_wildcard.index('dynamic_*')

        Dir.glob(path_with_wildcard) do |file|
          style_name = file[style_position..-1].split('/').first

          # In the event that the style name is used as the filename,
          # we want to remove the extension for our style name
          add_dynamic_style! File.basename(style_name, File.extname(style_name))
        end
      end
    end

    def styles
      super.merge dynamic_styles
    end

    def process_dynamic_style(style_name)
      add_dynamic_style! style_name
      reprocess! style_name
    end

    def dynamic_url(definition)
      raise DynamicPaperclip::Errors::SecretNotSet, "No secret has been configured. Please run the dynamic_paperclip:install generator." unless DynamicPaperclip.config.secret.present?

      style_name = StyleNaming.dynamic_style_name_from_definition(definition)

      url = url(style_name)

      delimiter_char = url.match(/\?.+=/) ? '&' : '?'

      "#{url}#{delimiter_char}s=#{UrlSecurity.generate_hash(style_name)}"
    end

    private

      def add_dynamic_style!(name)
        @dynamic_styles[name.to_sym] = Paperclip::Style.new(name, StyleNaming.style_definition_from_dynamic_style_name(name), self)
      end
  end
end```
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