test: add a couple of tests for system-update-generator

diff --git a/test/units/testsuite-81.system-update-generator.sh b/test/units/testsuite-81.system-update-generator.sh
new file mode 100755 (executable)
index 0000000..6dfee0d
--- /dev/null
+++ b/test/units/testsuite-81.system-update-generator.sh
@@ -0,0 +1,38 @@
+#!/usr/bin/env bash
+# SPDX-License-Identifier: LGPL-2.1-or-later
+# shellcheck disable=SC2235
+set -eux
+set -o pipefail
+
+# shellcheck source=test/units/generator-utils.sh
+. "$(dirname "$0")/generator-utils.sh"
+
+GENERATOR_BIN="/usr/lib/systemd/system-generators/systemd-system-update-generator"
+OUT_DIR="$(mktemp -d /tmp/system-update-generator-generator.XXX)"
+
+at_exit() {
+    rm -frv "${OUT_DIR:?}" /system-update
+}
+
+trap at_exit EXIT
+
+test -x "${GENERATOR_BIN:?}"
+
+rm -f /system-update
+
+: "system-update-generator: no /system-update flag"
+run_and_list "$GENERATOR_BIN" "$OUT_DIR"
+[[ "$(find "$OUT_DIR" ! -type d | wc -l)" -eq 0 ]]
+
+: "system-update-generator: with /system-update flag"
+touch /system-update
+run_and_list "$GENERATOR_BIN" "$OUT_DIR"
+link_endswith "$OUT_DIR/early/default.target" "/lib/systemd/system/system-update.target"
+
+: "system-update-generator: kernel cmdline warnings"
+# We should warn if the default target is overriden on the kernel cmdline
+# by a runlevel or systemd.unit=, but still generate the symlink
+SYSTEMD_PROC_CMDLINE="systemd.unit=foo.bar 3" run_and_list "$GENERATOR_BIN" "$OUT_DIR" |& tee /tmp/system-update-generator.log
+link_endswith "$OUT_DIR/early/default.target" "/lib/systemd/system/system-update.target"
+grep -qE "Offline system update overridden .* systemd.unit=" /tmp/system-update-generator.log
+grep -qE "Offline system update overridden .* runlevel" /tmp/system-update-generator.log