--- /dev/null
+require 'rack/utils'
+
+module Rack
+
+ # Sets the Content-Type header on responses which don't have one.
+ #
+ # Builder Usage:
+ # use Rack::ContentType, "text/plain"
+ #
+ # When no content type argument is provided, "text/html" is assumed.
+ class ContentType
+ def initialize(app, content_type = "text/html")
+ @app, @content_type = app, content_type
+ end
+
+ def call(env)
+ status, headers, body = @app.call(env)
+ headers = Utils::HeaderHash.new(headers)
+ headers['Content-Type'] ||= @content_type
+ [status, headers.to_hash, body]
+ end
+ end
+end