```ruby
require "turbo_dev_assets/version"

# this class cheats and bypasses rails altogether if the client attempts
# to download a static asset
class TurboDevAssets
  def initialize(app, settings={})
    @app = app
  end
  def call(env)
    # hack to bypass all middleware if serving assets, a lot faster 4.5 seconds -> 1.5 seconds
    if (etag = env['HTTP_IF_NONE_MATCH']) && env['REQUEST_PATH'] =~ /^\/assets\//
      name = $'
      etag = etag.gsub "\"", ""
      asset = Rails.application.assets.find_asset(name)
      if asset && asset.digest == etag
        return [304,{},[]]
      end
    end

    @app.call(env)
  end
end
```

Use `no-cache` in development mode for assets. Using `must-revalidate`, which is Rails' default, seems to have Chrome sometimes not request assets in development mode even though it's supposed to revalidate every time.
user
```ruby
require "turbo_dev_assets/version"

# this class cheats and bypasses rails altogether if the client attempts
# to download a static asset
class TurboDevAssets
  def initialize(app, settings={})
    @app = app
  end
  def call(env)

    is_asset = (env['REQUEST_PATH'] =~ /^\/assets\//)

    # hack to bypass all middleware if serving assets, a lot faster 4.5 seconds -> 1.5 seconds
    if (etag = env['HTTP_IF_NONE_MATCH']) && is_asset
      name = $'
      etag = etag.gsub "\"", ""
      asset = Rails.application.assets.find_asset(name)
      if asset && asset.digest == etag
        return [304,{},[]]
      end
    end

    status, headers, response = @app.call(env)
    headers['Cache-Control'] = 'no-cache' if is_asset
    [status, headers, response]
  end
end
```
assistant