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@xxxxxxxxxxxxxxxxxxxxx/ 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@xxxxxxxxxxxxxxxxxxxxx/ [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@xxxxxxxxxxxxxxxxxxxxx/ -Peff
