I understand the idea of refactoring code to make it testable. I very much appreciate the clarification on usage. Thank you. But... As I see it, this approach to testing code is beyond counterintuitive, at least at first glance. It takes a moment to realize that wrapping the test call in a lambda definition or a thunk is basically creating a delayed unit of computation. Not something I want to teach my students about during the first week of class, I think.
What I intend to do is require them to unit test their code before they submit it. I have never used rackunit before, so I thought I would give it a try before I make them use it. IS testing really this complex, or am I missing some larger idea here? George -----Original Message----- From: Asumu Takikawa [mailto:as...@ccs.neu.edu] Sent: Tuesday, August 27, 2013 4:35 PM To: George Rudolph Cc: users@racket-lang.org Subject: Re: [racket] Help with exception raising and testing On 2013-08-27 14:33:54 -0400, George Rudolph wrote: > #lang racket > > (require rackunit "mybasic.rkt") > > (test-exn "negative coin" negative? (sum-coins -1 3 5 7) ) There is a common mistake here that myself and other Racket programmers frequently make. The various rackunit functions that deal with exceptions take a *thunk* that contains the code to run. So `(sum-coins -1 3 5 7)` should be `(λ () (sum-coins -1 3 5 7))` or `(thunk (sum-coins -1 3 5 7))`. In addition, the test predicate should take an exception value so `negative?` won't work. You probably want a predicate like `(λ (e) (regexp-match #rx"negative?" (exn-message e)))` instead. Cheers, Asumu ____________________ Racket Users list: http://lists.racket-lang.org/users
