test: run_subtests_and_exit helper

Replace the "run_subtests; touch /testok" tail with a single wrapper
invocation. Report the test itself as skipped if every subtest is
skipped.

Signed-off-by: Paul Meyer <katexochen0@gmail.com>

test/units/TEST-04-JOURNAL.sh

@@ -6,6 +6,4 @@ set -o pipefail
 # shellcheck source=test/units/test-control.sh
 . "$(dirname "$0")"/test-control.sh
 
-run_subtests
-
-touch /testok
+run_subtests_and_exit

test/units/TEST-05-RLIMITS.sh

@@ -6,6 +6,4 @@ set -o pipefail
 # shellcheck source=test/units/test-control.sh
 . "$(dirname "$0")"/test-control.sh
 
-run_subtests
-
-touch /testok
+run_subtests_and_exit

test/units/TEST-13-NSPAWN.sh

@@ -18,6 +18,4 @@ fi
 # shellcheck source=test/units/test-control.sh
 . "$(dirname "$0")"/test-control.sh
 
-run_subtests
-
-touch /testok
+run_subtests_and_exit

test/units/TEST-17-UDEV.sh

@@ -8,6 +8,4 @@ set -o pipefail
 
 udevadm settle
 
-run_subtests
-
-touch /testok
+run_subtests_and_exit

test/units/TEST-19-CGROUP.sh

@@ -6,6 +6,4 @@ set -o pipefail
 # shellcheck source=test/units/test-control.sh
 . "$(dirname "$0")"/test-control.sh
 
-run_subtests
-
-touch /testok
+run_subtests_and_exit

test/units/TEST-22-TMPFILES.sh

@@ -14,6 +14,4 @@ if systemd-detect-virt --quiet --container; then
     ln -s /dev/null /run/tmpfiles.d/selinux-policy.conf
 fi
 
-run_subtests
-
-touch /testok
+run_subtests_and_exit

test/units/TEST-23-UNIT-FILE.sh

@@ -7,6 +7,4 @@ set -o pipefail
 . "$(dirname "$0")"/test-control.sh
 
 # Note: the signal shenanigans are necessary for the Upholds= tests
-run_subtests_with_signals SIGUSR1 SIGUSR2 SIGRTMIN+1
-
-touch /testok
+run_subtests_with_signals_and_exit SIGUSR1 SIGUSR2 SIGRTMIN+1

test/units/TEST-53-TIMER.sh

@@ -6,6 +6,4 @@ set -o pipefail
 # shellcheck source=test/units/test-control.sh
 . "$(dirname "$0")"/test-control.sh
 
-run_subtests
-
-touch /testok
+run_subtests_and_exit

test/units/TEST-70-TPM2.sh

@@ -6,6 +6,4 @@ set -o pipefail
 # shellcheck source=test/units/test-control.sh
 . "$(dirname "$0")"/test-control.sh
 
-run_subtests
-
-touch /testok
+run_subtests_and_exit

test/units/TEST-74-AUX-UTILS.sh

@@ -6,6 +6,4 @@ set -o pipefail
 # shellcheck source=test/units/test-control.sh
 . "$(dirname "$0")"/test-control.sh
 
-run_subtests
-
-touch /testok
+run_subtests_and_exit

test/units/TEST-81-GENERATORS.sh

@@ -6,6 +6,4 @@ set -o pipefail
 # shellcheck source=test/units/test-control.sh
 . "$(dirname "$0")"/test-control.sh
 
-run_subtests
-
-touch /testok
+run_subtests_and_exit

test/units/TEST-90-RESTRICT-FSACCESS.sh

@@ -6,6 +6,4 @@ set -o pipefail
 # shellcheck source=test/units/test-control.sh
 . "$(dirname "$0")"/test-control.sh
 
-run_subtests
-
-touch /testok
+run_subtests_and_exit

test/units/test-control.sh

@@ -172,6 +172,31 @@ run_subtests() {
     _show_summary
 }
 
+_finalize_subtests() {
+    if [[ ${#_PASSED_TESTS[@]} -eq 0 && ${#_SKIPPED_TESTS[@]} -gt 0 ]]; then
+        echo "All subtests skipped" | tee --append /skipped
+        exit "$_SUBTEST_SKIP_RC"
+    fi
+
+    touch /testok
+    exit 0
+}
+
+# Run all subtests and finalize the test in one shot: exit 77 (skipped) if every subtest skipped,
+# otherwise mark success (/testok) and exit. Use this ONLY for tests whose body is just subtests.
+# Do NOT use it if the parent script has meaningful test content of its own.
+run_subtests_and_exit() {
+    run_subtests
+    _finalize_subtests
+}
+
+# Like run_subtests_and_exit, but propagates the given signals to the subtests (see
+# run_subtests_with_signals).
+run_subtests_with_signals_and_exit() {
+    run_subtests_with_signals "$@"
+    _finalize_subtests
+}
+
 # Run all test cases (i.e. functions prefixed with testcase_ in the current namespace)
 run_testcases() {
     local testcase testcases