hu.dwim.stefil is an abandoned test framework with a living fork at fiasco, and its philosophy is to stay as transparent as possible, disrupting the normal Lisp application development process as little as possible.

License: Public Domain / BSD

What Stefil basically adds is that it quietly gathers extra runtime information and statistics (like a test backtraces, assertions, failures and/or errors), and introduces a wider range of ASSERT-like primitives to express the expected behavior of a program. It also integrates well with the Slime inspector, and provides useful restarts to achieve that goal.

Unique Selling Points:

  • Non-intrusive to the normal development process (debugging a failed test is exactly the same experience as debugging your application)
  • Integrates well with Slime
  • Lets you run tests both in non-interactive and in interactive mode with useful restarts
  • Makes it trivial to invoke even only parts of the test suite: just call the DEFTEST (DEFUN) of your choice
  • Allows you to interactively skip parts of the test suite (e.g. to skip a long test (and remember that suite are also tests) you can abort with C-c C-c and select a restart)
  • Its fixture implementation allows invoking specific parts of the test suite without sacrificing performance


Maintainers: Levente Mészáros, Tamás Borbély and Attila Lendvai.

Current darcs repository is available at:

Notable packages using stefil for testing include:

Old version called stefil

Homepage, including some documentation:

Older version of stefil is hosted by Luís Oliveira and can be found at:

Both new and old versions are Quicklisp installable using package names hu.dwim.stefil and stefil.