t3701: add a test for interactive.diffFilter

This feature was added in 01143847db (add--interactive: allow custom diff highlighting programs, 2016-02-27) but never tested. Let's add a basic test. Note that we only apply the filter when color is enabled, so we have to use test_terminal. This is an open limitation explicitly mentioned in the original commit. So take this commit as testing the status quo, and not making a statement on whether we'd want to enhance that in the future. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Jeff King committed Mar 3, 2018 at 00:58 UTC af3570ed6ca97605d62ebe1836fc893014ae844b
1 file changed +12
t/t3701-add-interactive.sh
+12
@@ -392,6 +392,18 @@ test_expect_success TTY 'diffs can be colorized' '
392 grep "$(printf "\\033")" output
393 '
394
395 +test_expect_success TTY 'diffFilter filters diff' '
396 + git reset --hard &&
397 +
398 + echo content >test &&
399 + test_config interactive.diffFilter "sed s/^/foo:/" &&
400 + printf y | test_terminal git add -p >output 2>&1 &&
401 +
402 + # avoid depending on the exact coloring or content of the prompts,
403 + # and just make sure we saw our diff prefixed
404 + grep foo:.*content output
405 +'
406 +
407 test_expect_success 'patch-mode via -i prompts for files' '
408 git reset --hard &&
409