connect four (game)

[Chris Angelico]

On Sun, Nov 26, 2017 at 3:36 AM, Ian Kelly <ian.g.kelly at gmail.com> wrote:
> On Sat, Nov 25, 2017 at 6:00 AM, bartc <bc at freeuk.com> wrote:
>> Where are your unittests for these unittests?
>
> No, the point of having unit tests is to build confidence that the
> code in question works correctly. It's *possible* that the code is
> broken, and that the test is also broken in a way that hides the
> brokenness of the code, but this is much less likely than the case
> where just the code is broken. This is also the reason why the
> philosophy of test-drive development stipulates that one should write
> the test *first*, run it and watch it fail (this ensures that the test
> is actually testing *something*) and then and only then write the code
> to make the test pass.

To be fair, TDD doesn't actually prove that the test isn't broken. It
only protects you against one class of error: tests that actually
aren't testing anything. Proponents of TDD will argue that this class
of error is quite common; true or not, it's still only one particular
kind of failure. It's definitely possible for tests to be wrong in
such a way that they don't detect faulty code.

So what do we do? WE TEST BY HAND. Ultimately, unit testing is a tool,
not a magic wand. It's up to us to actually put it to use to improve
code quality.

ChrisA