[tz] Adding a "test" region?

[Robert Elz]

  From: Stephen Colebourne <scolebourne at joda.org>
  Date: Thu, 25 Jan 2018 16:53:22 +0000
  Subject: Re: [tz] Adding a "test" region?

  | I'm not part of CLDR, nor am I paid to work on date/time issues.

But, it was earlier said, someone apparently is, right?

  | It can be tested for a specific stack, but not for all possible stacks
  | (as I indicated in the other thread).

Why?   Obviously each stack developer only tests their own, it is not
a case of one person or organisation being expected to test everything,
that would obviously be absurd.

But if there was a zone designed for testing (or a set of such zones)
then each developer could fairly easily (I would hope) test their
stack (or stacks if they are responsible for more than one) using that
zone (in addition to the others the test suites presumably already use.)

I would certainly augment the NetBSD time, timezone and date-parsing
tests to include such a zone if one were available.

  | As such, I think a test file might at best act as an early warning
  | of what will be a problem, not necessarily as a way to get those
  | problems solved.

Of course, that's the idea - they let you know what fails (if anything)
before the failures are present in a zone that is important (if some
stack fails on the test zone, that doesn't prevent it still being used
for more normal zones, while whatever it is is yet to appear there).

Tests like this are also helpful in making sure that code changes do
not break things - and for that, you want tests that really push the
corner cases.  A test zone with wildly improbable (but possible) data
in it would be extremely useful for such scenarios.   And no, I don't
care what it is called (just as long as someone tells me!)  It could
be Australia/New_York for all I care.

kre