From 1abc832afa5bd575131b41a3b9ce5fa8f2db9a20 Mon Sep 17 00:00:00 2001
From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Fri, 14 Sep 2018 14:42:13 -0500
Subject: [PATCH] tests: introduce `test_atexit`

When running the p4 daemon or `git daemon`, we want to kill it at the
end of the test script.

So far, we do this "manually".

However, in the next few commits we want to teach the test suite to
optionally re-run scripts with different options, therefore we will have
to have a consistent way to stop daemons.

Let's introduce `test_atexit`, which is loosely modeled after
`test_when_finished` (but has a broader scope: rather than running the
commands after the current test case, run them when the test script
finishes, and also run them when the `--immediate` option is in effect).

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---
 t/t0000-basic.sh        | 18 ++++++++++++++++++
 t/test-lib-functions.sh | 29 +++++++++++++++++++++++++++++
 t/test-lib.sh           |  4 ++++
 3 files changed, 51 insertions(+)

diff --git a/t/t0000-basic.sh b/t/t0000-basic.sh
index 850f651e4e..3df22e3989 100755
--- a/t/t0000-basic.sh
+++ b/t/t0000-basic.sh
@@ -821,6 +821,24 @@ test_expect_success 'tests clean up even on failures' "
 	EOF
 "
 
+test_expect_success 'test_atexit is run' "
+	test_must_fail run_sub_test_lib_test \
+		atexit-cleanup 'Run atexit commands' -i <<-\\EOF &&
+	test_expect_success 'tests clean up even after a failure' '
+		> ../../clean-atexit &&
+		test_atexit rm ../../clean-atexit &&
+		> ../../also-clean-atexit &&
+		test_atexit rm ../../also-clean-atexit &&
+		> ../../dont-clean-atexit &&
+		(exit 1)
+	'
+	test_done
+	EOF
+	test_path_exists dont-clean-atexit &&
+	test_path_is_missing clean-atexit &&
+	test_path_is_missing also-clean-atexit
+"
+
 ################################################################
 # Basics of the basics
 
diff --git a/t/test-lib-functions.sh b/t/test-lib-functions.sh
index 4207af4077..98c981f4dc 100644
--- a/t/test-lib-functions.sh
+++ b/t/test-lib-functions.sh
@@ -889,6 +889,35 @@ test_when_finished () {
 		} && (exit \"\$eval_ret\"); eval_ret=\$?; $test_cleanup"
 }
 
+# This function can be used to schedule some commands to be run
+# unconditionally at the end of the test script, e.g. to stop a daemon:
+#
+#	test_expect_success 'test git daemon' '
+#		git daemon &
+#		daemon_pid=$! &&
+#		test_atexit "kill $daemon_pid" &&
+#		hello world
+#	'
+
+test_atexit () {
+	# We cannot detect when we are in a subshell in general, but by
+	# doing so on Bash is better than nothing (the test will
+	# silently pass on other shells).
+	test "${BASH_SUBSHELL-0}" = 0 ||
+	error "bug in test script: test_atexit does nothing in a subshell"
+	test_atexit_cleanup="{ $*
+		} && (exit \"\$eval_ret\"); eval_ret=\$?; $test_atexit_cleanup"
+}
+
+test_atexit_handler () {
+	test : != "$test_atexit_cleanup" || return 0
+
+	setup_malloc_check
+	test_eval_ "$test_atexit_cleanup"
+	test_atexit_cleanup=:
+	teardown_malloc_check
+}
+
 # Most tests can use the created repository, but some may need to create more.
 # Usage: test_create_repo <directory>
 test_create_repo () {
diff --git a/t/test-lib.sh b/t/test-lib.sh
index eaa752da4d..6b13fa45f9 100644
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -415,6 +415,7 @@ test_external_has_tap=0
 
 die () {
 	code=$?
+	test_atexit_handler || code=$?
 	if test -n "$GIT_EXIT_OK"
 	then
 		exit $code
@@ -828,9 +829,12 @@ write_junit_xml_testcase () {
 	junit_have_testcase=t
 }
 
+test_atexit_cleanup=:
 test_done () {
 	GIT_EXIT_OK=t
 
+	test -n "$immediate" || test_atexit_handler
+
 	if test -n "$write_junit_xml" && test -n "$junit_xml_path"
 	then
 		test -n "$junit_have_testcase" || {