Re: [PATCH v3 3/3] config: add '--show-origin' option to print the origin of a config value

Hi Peff,

tl;dr let's keep an eye on adding only test cases that do not depend on
earlier test cases' output ('setup' excluded, of course).

On Sun, 14 Feb 2016, Jeff King wrote:

In general, my opinion is that skipping arbitrary leading tests is a
losing strategy. It's just too easy to introduce hidden dependencies,
and not worth the programmer time to make sure each test runs in
isolation. But others on the list may disagree.

Yes, I disagree. And you would, too, if you had to run as many tests as I
had to do by way of js/mingw-tests. I did not keep precise track of time,
but I am certain that I had to run one of those bloody tests (forgot which
one) around 100 times, each taking roughly 3 minutes to complete, and of
course, it was the *last* test case failing, and *of course* it depended
on earlier tests to run.

It gets even worse when you think about those test cases that depend on
some prereq such as SYMLINKS or POSIXPERM. In *most* cases does the
developer who adds them not even notice that these prerequisites are
required. And subsequent test cases that do *not* share those
prerequisites depend (of course!) on the previous test cases' output.

Don't get me wrong, I think it would be too much pain for little gain to
clean up our act now. But I think that we have ample evidence that it
would be a plenty good idea to try pretty hard to avoid adding to the
pile.

Ciao,
Dscho