tests: add a smoke test for --version option in binaries

This is very similar to (and directly based on) the test for --help. I think
it's nice to do this: the test is very quick, but it'll catch cases where we
forgot to hook up the option, or forgot to exit after printing --version, and
it'll also increase our test coverage a bit.

1 files changed, 36 insertions, 0 deletions

diff --git a/tools/check-version.sh b/tools/check-version.sh
new file mode 100755
index 0000000000..faefb46883
--- /dev/null
+++ b/tools/check-version.sh
@@ -0,0 +1,36 @@
+#!/usr/bin/env bash
+# SPDX-License-Identifier: LGPL-2.1-or-later
+set -eu
+set -o pipefail
+
+# Note: 'grep ... >/dev/null' instead of just 'grep -q' is used intentionally
+#       here, since 'grep -q' exits on the first match causing SIGPIPE being
+#       sent to the sender.
+
+BINARY="${1:?}"
+VERSION="${2:?}"
+export SYSTEMD_LOG_LEVEL=info
+
+if [[ ! -x "$BINARY" ]]; then
+    echo "$BINARY is not an executable"
+    exit 1
+fi
+
+# --version prints something. Also catches case where args are ignored.
+if ! "$BINARY" --version | grep . >/dev/null; then
+    echo "$(basename "$BINARY") --version output is empty"
+    exit 2
+fi
+
+# no --version output to stderr
+if "$BINARY" --version 2>&1 1>/dev/null | grep .; then
+    echo "$(basename "$BINARY") --version prints to stderr"
+    exit 3
+fi
+
+# project version appears in version output
+out="$("$BINARY" --version)"
+if ! grep -F "$VERSION" >/dev/null <<<"$out"; then
+    echo "$(basename "$BINARY") --version output does not match '$VERSION': $out"
+    exit 4
+fi