From: Joel VanderWerf <joelvanderwerf@...>
Date: 2010-10-16T03:57:31+09:00
Subject: Re: [TestUnit pack] Unequal equality

On 10/15/2010 11:45 AM, felix.leg wrote:
> I've got such that output during testing my program:
> [terminal_output]
> Loaded suite ./niep_test
> Started
> ....F.
> Finished in 0.009922 seconds.
>
> 1) Failure:
> test_sanity(SFTester)
> [./niep_test.rb:12:in `sanity'
> ./niep_test.rb:19:in `test_sanity']:
> <7.8e-11> expected but was
> <7.8e-11>.
>
> 6 tests, 9 assertions, 1 failures, 0 errors
> [/terminal_output]
>
> A you can see the assert_equal function reports that something equal is
> not equal. WTF? Is it some bug in TestUnit package, or my program just
> looks to work fine?
>

Probably it's due to IEEE floating point inaccuracy. Try using 
assert_in_delta instead of assert_equal whenever you compare floats in a 
test.