Rant after trying Rust a bit

[Dicebot via Digitalmars-d]

On Saturday, 25 July 2015 at 14:28:31 UTC, Andrei Alexandrescu 
wrote:
> On 7/25/15 9:35 AM, Dicebot wrote:
>> This is absolutely impractical. I will never even consider 
>> such attitude
>> as a solution for production projects. If test coverage can't 
>> be
>> verified automatically, it is garbage, period. No one will 
>> ever manually
>> verify thousands lines of code after some trivial refactoring 
>> just to
>> make sure compiler does its job.
>
> Test coverage shouldn't totter up and down as application code 
> is written - it should be established by the unittests. And yes 
> one does need to examine coverage output while writing 
> unittests.

Does word "refactoring" or "adding new features" ring a bell? In 
the first case no one manually checks coverage of all affected 
code because simply too much code is affected. Yet it can become 
reduced by an accident. In the second case developer is likely to 
check coverage for actual functionality he has written - and yet 
coverage can become reduced in different (but related) parts of 
code because that is how templates work.

You will have a very hard time selling this approach. If official 
position of language authors is that one must manually check test 
coverage all the time over and over again, pragmatical people 
will look into other languages.

> I do agree more automation is better here (as is always). For 
> example, if a template is followed by one or more unittests, 
> the compiler might issue an error if the unittests don't cover 
> the template.

This isn't "better". This is bare minimum for me to call that 
functionality effectively testable. Manual approach to testing 
doesn't work, I thought everyone has figured that out by 2015. It 
works better than no tests at all, sure, but this is not 
considered enough anymore.