test: use jq // empty instead of grep -v null in Unit.List tests

Replace `grep -v null` with jq's `// empty` alternative operator when filtering unit IDs. With `set -o pipefail`, `grep` returns 1 when no lines match, which aborts the script before conditional guards can run. The `// empty` operator suppresses null output directly in jq without risking a pipeline failure.

diff --git a/test/units/TEST-74-AUX-UTILS.varlinkctl.sh b/test/units/TEST-74-AUX-UTILS.varlinkctl.sh
index ee5d762b5aa77d8f1e97372b47df2aa7c862f8b2..3e78cf34e9e486e2791997c7dcf02d707455f29c 100755 (executable)
--- a/test/units/TEST-74-AUX-UTILS.varlinkctl.sh
+++ b/test/units/TEST-74-AUX-UTILS.varlinkctl.sh
@@ -233,7 +233,7 @@ varlinkctl call /run/systemd/io.systemd.Manager io.systemd.Unit.List "{\"invocat
 # test for KillContext
 varlinkctl call /run/systemd/io.systemd.Manager io.systemd.Unit.List '{"pid": {"pid": 0}}' | jq -e '.context.Kill'
 # test for AutomountContext/Runtime
-automount_id=$(varlinkctl call --collect /run/systemd/io.systemd.Manager io.systemd.Unit.List '{}' | jq -r '.[] | select(.context.Type == "automount" and .runtime.LoadState == "loaded") .context.ID' | grep -v null | tail -n 1)
+automount_id=$(varlinkctl call --collect /run/systemd/io.systemd.Manager io.systemd.Unit.List '{}' | jq -r '.[] | select(.context.Type == "automount" and .runtime.LoadState == "loaded") .context.ID // empty' | tail -n 1)
 test -n "$automount_id"
 # Use jq to JSON-encode the unit name as it may contain backslash escapes (e.g. \x2d) that
 # are not valid JSON escape sequences and would be rejected by varlinkctl's JSON parser.
@@ -241,19 +241,19 @@ automount_params=$(jq -cn --arg name "$automount_id" '{name: $name}')
 varlinkctl call /run/systemd/io.systemd.Manager io.systemd.Unit.List "$automount_params" | jq -e '.context.Automount'
 varlinkctl call /run/systemd/io.systemd.Manager io.systemd.Unit.List "$automount_params" | jq -e '.runtime.Automount'
 # test for MountContext/Runtime
-mount_id=$(varlinkctl call --collect /run/systemd/io.systemd.Manager io.systemd.Unit.List '{}' | jq -r '.[] | select(.context.Type == "mount" and .runtime.LoadState == "loaded") .context.ID' | grep -v null | tail -n 1)
+mount_id=$(varlinkctl call --collect /run/systemd/io.systemd.Manager io.systemd.Unit.List '{}' | jq -r '.[] | select(.context.Type == "mount" and .runtime.LoadState == "loaded") .context.ID // empty' | tail -n 1)
 test -n "$mount_id"
 mount_params=$(jq -cn --arg name "$mount_id" '{name: $name}')
 varlinkctl call /run/systemd/io.systemd.Manager io.systemd.Unit.List "$mount_params" | jq -e '.context.Mount'
 varlinkctl call /run/systemd/io.systemd.Manager io.systemd.Unit.List "$mount_params" | jq -e '.runtime.Mount'
 # test for PathContext/Runtime
-path_id=$(varlinkctl call --collect /run/systemd/io.systemd.Manager io.systemd.Unit.List '{}' | jq -r '.[] | select(.context.Type == "path" and .runtime.LoadState == "loaded") .context.ID' | grep -v null | tail -n 1)
+path_id=$(varlinkctl call --collect /run/systemd/io.systemd.Manager io.systemd.Unit.List '{}' | jq -r '.[] | select(.context.Type == "path" and .runtime.LoadState == "loaded") .context.ID // empty' | tail -n 1)
 test -n "$path_id"
 path_params=$(jq -cn --arg name "$path_id" '{name: $name}')
 varlinkctl call /run/systemd/io.systemd.Manager io.systemd.Unit.List "$path_params" | jq -e '.context.Path'
 varlinkctl call /run/systemd/io.systemd.Manager io.systemd.Unit.List "$path_params" | jq -e '.runtime.Path'
 # test for ScopeContext/Runtime
-scope_id=$(varlinkctl call --collect /run/systemd/io.systemd.Manager io.systemd.Unit.List '{}' | jq -r '.[] | select(.context.Type == "scope" and .runtime.LoadState == "loaded") .context.ID' | grep -v null | tail -n 1)
+scope_id=$(varlinkctl call --collect /run/systemd/io.systemd.Manager io.systemd.Unit.List '{}' | jq -r '.[] | select(.context.Type == "scope" and .runtime.LoadState == "loaded") .context.ID // empty' | tail -n 1)
 test -n "$scope_id"
 scope_params=$(jq -cn --arg name "$scope_id" '{name: $name}')
 varlinkctl call /run/systemd/io.systemd.Manager io.systemd.Unit.List "$scope_params" | jq -e '.context.Scope'
@@ -266,7 +266,7 @@ if test -n "$swap_id"; then
     varlinkctl call /run/systemd/io.systemd.Manager io.systemd.Unit.List "$swap_params" | jq -e '.runtime.Swap'
 fi
 # test for TimerContext/Runtime
-timer_id=$(varlinkctl call --collect /run/systemd/io.systemd.Manager io.systemd.Unit.List '{}' | jq -r '.[] | select(.context.Type == "timer" and .runtime.LoadState == "loaded") .context.ID' | grep -v null | tail -n 1)
+timer_id=$(varlinkctl call --collect /run/systemd/io.systemd.Manager io.systemd.Unit.List '{}' | jq -r '.[] | select(.context.Type == "timer" and .runtime.LoadState == "loaded") .context.ID // empty' | tail -n 1)
 test -n "$timer_id"
 timer_params=$(jq -cn --arg name "$timer_id" '{name: $name}')
 varlinkctl call /run/systemd/io.systemd.Manager io.systemd.Unit.List "$timer_params" | jq -e '.context.Timer'