Re: [PATCH 3/3] test-lib: '--run' to run only specific tests

From: Junio C Hamano <gitster@pobox.com>
Date: May 6, 2014, 21:02 UTC
Message-ID: <xmqqfvkmei3c.fsf@gitster.dls.corp.google.com>
In-Reply-To: <xmqqk39yeiic.fsf@gitster.dls.corp.google.com>

Junio C Hamano <gitster@pobox.com> writes:

> The need to explain better with longer description will reduce the
> likelyhood that the feature is understood and correctly used.  When
> you can write "1-2,4-", why accept "1-4 !3" and force yourself to
> explain to people why that is different from "!3 1-4"?

By the way, having said all that, I would understand if the result is made not depend on the order of selectors given to the option.

That is:

 - Find all the positive ones and form the "positive" set; if there is
   no positive ones, then make the "positive" set include everything.

 - Find all the negative ones and form a "negative" set.  The
   "negative" set can be an empty set if there is no negative
   selector.

 - Subtract the "negative" set from the "positive" set, and run only
   the tests in the resulting set.

Then "1-4 !3" and "!3 1-4" would mean the same thing. Explanation of the semantics would be far simpler than "we do it from left to right".

One reason why the orders shouldn't matter is, unlike the "print dialog" case, we won't run tests out of order when given "1 4 3 2". We will still run "1-4". So it would be natural for the readers to expect that the orders they give selectors would not matter.