Re: [Module::Build] version.pm and version number comparison problem

[Chris D. <ch...@cl...>]

On Feb 2, 2006, at 10:17 PM, Ken Williams wrote:

> On Feb 2, 2006, at 10:22 AM, Chris Dolan wrote:
>
>> While we're at it, we should change the
>>   UNIVERSAL::isa( $result, 'version' )
>> to
>>   eval { $result->isa('version') }
>
> BTW, I actually tried this, and it broke the t/xs.t tests.  I'll  
> leave the reason why as an interesting exercise for the reader. =)
>
>  -Ken


[SPOILER BELOW!]


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It's a false failure.  t/xs.t is calling dispatch() and testing $@ to  
see if they fail.  The die() triggered by isa() inside the eval sets  
$@, and the test fails because $@ is set.  However, this is because t/ 
xs.t mistakenly omits wrapping some of the calls to dispatch() in  
their own eval{}.  The following test (#2 of 22) passes in xs.t:

    eval {$mb->dispatch('build')};
    is $@, '';

but this test (#20 of 22) erroneously fails:

    $mb->dispatch('build');
    is $@, '';

So the test is checking $@ from the wrong eval.


The moral of the story is that using best practices help you find  
bugs in code.  ;-)

Chris
-- 
Chris Dolan, Software Developer, Clotho Advanced Media Inc.
608-294-7900, fax 294-7025, 1435 E Main St, Madison WI 53703
vCard: http://www.chrisdolan.net/ChrisDolan.vcf

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