To test that we don't break the &&-chain, test-lib.sh does something
like:
(exit 117) && $test_commands
and checks that the result is exit code 117. We don't care what that
initial command is, as long as it exits with a unique code. Using "exit"
works and is simple, but is a bit expensive since it requires a subshell
(to avoid exiting the whole script!). This isn't usually very
noticeable, but it can add up for scripts which have a large number of
tests.
Using "return" naively won't work here, because we'd return from the
function eval-ing the snippet (and it wouldn't find &&-chain breakages).
But if we further push that into its own function, it does exactly what
we want, without extra subshell overhead.
According to hyperfine, this produces a measurable improvement when
running t3070 (which has 1800 tests, all of them quite short):
'HEAD' ran
1.09 ± 0.01 times faster than 'HEAD~1'
Signed-off-by: Jeff King <peff@xxxxxxxx>
---
t/test-lib.sh | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/t/test-lib.sh b/t/test-lib.sh
index 09789566374..cfcbd899c5a 100644
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -1086,6 +1086,10 @@ test_eval_ () {
return $test_eval_ret_
}
+fail_117 () {
+ return 117
+}
+
test_run_ () {
test_cleanup=:
expecting_failure=$2
@@ -1097,7 +1101,7 @@ test_run_ () {
trace=
# 117 is magic because it is unlikely to match the exit
# code of other programs
- if test "OK-117" != "$(test_eval_ "(exit 117) && $1${LF}${LF}echo OK-\$?" 3>&1)"
+ if test "OK-117" != "$(test_eval_ "fail_117 && $1${LF}${LF}echo OK-\$?" 3>&1)"
then
BUG "broken &&-chain or run-away HERE-DOC: $1"
fi
--
2.40.0.616.gf524ec75088
