From: Florian Gross <flgr@...>
Date: 2004-11-15T22:13:24+09:00
Subject: Re: assert

Bjorn Nordbo wrote:

> Gavin Sinclair <gsinclair@soyabean.com.au> writes:
>>It's not unlikely at all, actually.  Test cases are a clearly a good
>>way to set up the conditions you need to expose a bug.  That's when I
>>tend to use breakpoints very often.
> 
> I think there are are least two common scenarios described here:
> 
> 1. You want an assertion as kind of a "can't happen" test.
> 2. You want to set breakpoints to inspect the state.
> 
> In my opinion, the first is the traditional "assert" while the second is
> similiar to BREAK in Common Lisp.  The former is useful in both test and
> production code, while the latter only makes sense in test code.  These
> are different, and should have different names:
> 
> - "assert" or similiar to die horriby (except maybe when $DEBUG is set)
> - "breakpoint" or similiar to simply interrupt execution.

assert() doesn't die horribly in test cases either and when you find 
something wrong it can make sense to let a developer examine state so 
that the problem can be fixed instead of dieing without a way of 
diagnosing problems. I renamed the assert() that spawns an irb shell to 
assume() mostly to avoid collisions with test/unit. Personally I don't 
think it makes much sense to spawn an irb shell in test cases where you 
already have the problems clearly isolated anyway -- but test cases will 
require() the main application and if the main application still uses 
breakpoint.rb there will be a collision between test/unit's assert() and 
breakpoint's assert().

I guess assume() would be okay -- if anybody dislikes it and would 
rather use breakpoint() manually then great, I'm not forcing anybody to 
use assume() instead of breakpoint(). I have just found it useful to 
have both in my own code.

I just wonder if anybody would run into real problems because of 
breakpoint.rb providing assume().