Tyrex | Project

Automated Refactoring of Cascading Style Sheets

The Cascading Style Sheets (CSS) standard is the second most used standard on the web. The automated analysis of CSS stylesheets is a recent research topic that was pioneered in [1]. It was shown that Cascading style sheets can be semantically analysed with tree logics [1] and then refactored automatically with an additional set of refactoring rules [2]. This is useful for static bug detection, proving layout properties over all web pages that use the stylesheets, and for refactoring stylesheets automatically. In particular, it was shown in [2] that the size of CSS used in popular websites (such as Google Sites, Facebook, etc.) can be significantly reduced. One goal is to speed up the web page loading time by simplifying the visual layout process performed by the web browser.

This research topic aims at extending these works along several directions including:

  • further analysing of the speedup obtained in web page loading performance;
  • extending the logical analyses for more precise analyses and refactoring, in particular by considering types;
  • further benchmarking on popular CSS including e.g. bootstrap.

NB: this is a topic where we can easily set the balance between applied research and theoretical research.


  1. On the Analysis of Cascading Style Sheets. Pierre Geneves, Nabil Layaida, Vincent Quint. In WWW'12: Proceedings of the 21st International World Wide Web Conference (HAL , ACM DL)
  2. Reasoning with Style. Marti Bosch, Pierre Geneves, Nabil Layaida. In IJCAI'15: Proceedings of the Twenty-Fourth International Joint Conference on Artificial Intelligence (http://ijcai.org/papers15/Papers/IJCAI15-315.pdf)
  3. Automated Analysis of CSS Rules to Support Style Maintenance. Ali Mesbah, Shabnam Mirshokraie. In ICSE'12 (http://www.ece.ubc.ca/~shabnamm/doc/css-icse12.pdf)


Pierre Genevès (pierre.geneves@cnrs.fr), Nabil Layaïda (nabil.layaida@inria.fr)