I just had a sinking realization today: I have been using assert inside unittests to check for test results, but actually, this is wrong!

Why? Because when you compile with -release -unittest, all those asserts disappear, and the unittests become useless.  The correct way is to use enforce instead of assert.

Unfortunately, Phobos unittests are full of asserts rather than enforce. :-/

(And I contend that compiling with both -release and -unittest is a valid scenario: it lets you catch bugs that only show up in the release version, such as accidentally relying on side-effects in asserts, which work when compiling without -release, but mysteriously fail during -release. Failing unittests would allow you to catch such mistakes before you ship it to the irate customer.)


T

-- 
Computerese Irregular Verb Conjugation: I have preferences.  You have biases.  He/She has prejudices. -- Gene Wirchenko

On Thursday, 28 February 2013 at 04:52:01 UTC, H. S. Teoh wrote:
> Why? Because when you compile with -release -unittest, all those asserts
> disappear, and the unittests become useless.

Are you sure? The asserts work for me:

unittest
{
    int getZero() { return 0; }
    assert(getZero != 0);
}

void main() { }

$ dmd -release -unittest test.d
$ test.exe
> core.exception.AssertError@test(6): unittest failure

On Thursday, 28 February 2013 at 04:58:48 UTC, Andrej Mitrovic wrote:
> $ dmd -release -unittest test.d
> $ test.exe
>> core.exception.AssertError@test(6): unittest failure

Btw I think this might be an accident, in mars.c there's this code:

    if (global.params.release)
    {   global.params.useInvariants = 0;
        global.params.useIn = 0;
        global.params.useOut = 0;
        global.params.useAssert = 0;  // <-- note
        global.params.useArrayBounds = 1;
        global.params.useSwitchError = 0;
    }

However then it's followed by this code:

    if (global.params.useUnitTests)
        global.params.useAssert = 1;

So it's switched off and then on again. I can't tell if this was deliberate or not. If it's on purpose it should be documented.