From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DE84CC43603 for ; Tue, 17 Dec 2019 05:53:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BB4932072D for ; Tue, 17 Dec 2019 05:53:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727176AbfLQFxk (ORCPT ); Tue, 17 Dec 2019 00:53:40 -0500 Received: from cloud.peff.net ([104.130.231.41]:48328 "HELO cloud.peff.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1726772AbfLQFxj (ORCPT ); Tue, 17 Dec 2019 00:53:39 -0500 Received: (qmail 29892 invoked by uid 109); 17 Dec 2019 05:53:40 -0000 Received: from Unknown (HELO peff.net) (10.0.1.2) by cloud.peff.net (qpsmtpd/0.94) with SMTP; Tue, 17 Dec 2019 05:53:40 +0000 Authentication-Results: cloud.peff.net; auth=none Received: (qmail 20009 invoked by uid 111); 17 Dec 2019 05:58:15 -0000 Received: from coredump.intra.peff.net (HELO sigill.intra.peff.net) (10.0.0.2) by peff.net (qpsmtpd/0.94) with (TLS_AES_256_GCM_SHA384 encrypted) ESMTPS; Tue, 17 Dec 2019 00:58:15 -0500 Authentication-Results: peff.net; auth=none Date: Tue, 17 Dec 2019 00:53:38 -0500 From: Jeff King To: SZEDER =?utf-8?B?R8OhYm9y?= Cc: Johannes Schindelin via GitGitGadget , git@vger.kernel.org, Johannes Schindelin , Junio C Hamano Subject: Re: [PATCH 2/7] t3701: avoid depending on the TTY prerequisite Message-ID: <20191217055338.GC2762303@coredump.intra.peff.net> References: <20191216121859.GP6527@szeder.dev> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20191216121859.GP6527@szeder.dev> Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org On Mon, Dec 16, 2019 at 01:18:59PM +0100, SZEDER Gábor wrote: > > And we found exactly such a trick earlier already: when we added a test > > case to verify that the main loop of `git add -i` is colored > > appropriately. Let's use that trick instead of the TTY prerequisite. > > It's much more interesting _what_ that trick is than when it was > found. Is it setting TERM=vt100, or is it setting both TERM=vt100 and > GIT_PAGER_IN_USE=true? I'm inclined to think the latter, but I'm not > sure I interpreted the comment below right. It's both. GIT_PAGER_IN_USE tells Git not to bother checking isatty(), and then TERM=vt100 is necessary to override test-lib's TERM=dumb specifically for the color code. > In any case, there are a couple of tests in other test scripts that > test color relying on the TTY prereq. So maybe it would be worth to > make this into a "global" helper function by adding it to > 'test-lib-functions.sh', so we can drop a few more prereqs. > > OTOH, some of those other tests have descriptions like: > > t3203-branch-output.sh:test_expect_success TTY '%(color) present with tty' > t7004-tag.sh:test_expect_success TTY '%(color) present with tty' > > i.e. their description is specific about checking the behaviour with a > tty, so I'm not entirely sure. Hmm. I have mixed feelings on this. I do like the simplicity of avoiding test_terminal (which is unportable and has also contributed to some confusing behavior in the past[1]). But it also takes us further away from a real-world setup. That might be OK for the tests you quoted above, if we're OK with assuming the equivalence of isatty() and GIT_PAGER_IN_USE for the color code (though we'd probably want to make sure that's tested _somewhere_). But it obviously would not work for test-terminal callers that are checking the pager behavior. And I suspect it may create other oddities; e.g., a script which calls a sub-command that looks at GIT_PAGER_IN_USE, even though the sub-command's output is going to a pipe. Though one could argue that's a bug[2] (that could be triggered by _actually_ sending the script's output to pager). If we're going to get rid of test-terminal.pl (and I would be happy enough to see it go), I'd rather we mock things up at the isatty() level, something like what I showed in: https://lore.kernel.org/git/20190524062724.GC25694@sigill.intra.peff.net/ That gives us a more realistic setup, and we could reliably use it everywhere that test-terminal is used. -Peff [1] I had issues a while back with test-terminal's stdin feature being racy: https://lore.kernel.org/git/20190520125016.GA13474@sigill.intra.peff.net/ [2] Long ago I had a patch to make PAGER_IN_USE more careful by making sure that our pipe is the same as the pager pipe. It did (and does) work, but it would need some portability adjustments. I never bothered to follow up because it really does seem to be a pretty unlikely setup in practice. But if you're curious: https://lore.kernel.org/git/20150810052353.GB15441@sigill.intra.peff.net/ -Peff