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From:   Iurii Zaikin <yzaikin@google.com>
Date:   Wed, 30 Oct 2019 13:11:44 -0700
Message-ID: <CAAXuY3o31iCJwZ+WGHMaK1MgpC0qv=JkJWnzv8Lhym9TnZQvcQ@mail.gmail.com>
Subject: Re: [PATCH linux-kselftest/test v1] apparmor: add AppArmor KUnit
 tests for policy unpack
To:     Kees Cook <keescook@chromium.org>
Cc:     Luis Chamberlain <mcgrof@kernel.org>,
        Brendan Higgins <brendanhiggins@google.com>,
        Alan Maguire <alan.maguire@oracle.com>,
        Matthias Maennich <maennich@google.com>,
        shuah <shuah@kernel.org>,
        John Johansen <john.johansen@canonical.com>, jmorris@namei.org,
        serge@hallyn.com, David Gow <davidgow@google.com>,
        "Theodore Ts'o" <tytso@mit.edu>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        linux-security-module@vger.kernel.org,
        KUnit Development <kunit-dev@googlegroups.com>,
        "open list:KERNEL SELFTEST FRAMEWORK" 
        <linux-kselftest@vger.kernel.org>,
        Mike Salvatore <mike.salvatore@canonical.com>
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> Why can't unit tests live with the code they're testing? They're already
> logically tied together; what's the harm there? This needn't be the case
> for ALL tests, etc. The test driver could still live externally. The
> test in the other .c would just have exported functions... ?
>
Curiously enough, this approach has been adopted by D 2.0 where unittests are
members of the class under test:  https://digitalmars.com/d/2.0/unittest.html
but such approach is not mainstream.
I personally like the idea of testing the lowest level bits in isolation even if
they are not a part of any interface. I think that specifying the
interface using
unit tests and ensuring implementation correctness are complementary but
I haven't had much luck arguing this with our esteemed colleagues.