Ensure nested CLI components are fresh

scripts/test_dependency_invalidation.sh

@@ -21,6 +21,7 @@ mutation_file="/tmp/uce-dependency-mutation-$$"
 post_body="/tmp/uce-dependency-post-body-$$"
 post_headers="/tmp/uce-dependency-post-headers-$$"
 lock_ready_file="/tmp/uce-dependency-lock-ready-$$"
+nested_lock_ready_file="/tmp/uce-nested-lock-ready-$$"
 race_output="/tmp/uce-source-race-output-$$"
 race_error="/tmp/uce-source-race-error-$$"
 race_status="/tmp/uce-source-race-status-$$"
@@ -31,7 +32,7 @@ cleanup() {
 	if [[ -n "$cache_dir" ]]; then
 		rm -rf "$cache_dir"
 	fi
-	rm -f "$mutation_file" "$post_body" "$post_headers" "$lock_ready_file" "$race_output" "$race_error" "$race_status"
+	rm -f "$mutation_file" "$post_body" "$post_headers" "$lock_ready_file" "$nested_lock_ready_file" "$race_output" "$race_error" "$race_status"
 }
 trap cleanup EXIT
 mkdir -p "$source_dir"
@@ -175,6 +176,47 @@ if (( elapsed_ms < 2000 )); then
 fi
 wait "$rebuild_lock_pid"
 
+# CLI freshness applies to every nested component, not only the request entry
+# unit. Hold the changed child's compile lock as a proactive rebuild would: the
+# parent CLI request must wait and render the new child, never its stale wasm.
+printf '%s\n' 'COMPONENT(Request& context) { print("nested-component-marker-a"); }' >"$source_dir/nested-child.uce"
+printf '%s\n' \
+	'CLI(Request& context) { DValue props; print(component("nested-child", props, context)); }' >"$source_dir/nested-parent.uce"
+assert_marker nested-parent nested-component-marker-a
+nested_child_wasm="$cache_dir/nested-child.uce.wasm"
+(
+	exec 8>"$nested_child_wasm.lock"
+	flock 8
+	: >"$nested_lock_ready_file"
+	sleep 3
+) &
+nested_lock_pid=$!
+deadline=$((SECONDS + 5))
+while [[ ! -e "$nested_lock_ready_file" && $SECONDS -lt $deadline ]]; do
+	if ! kill -0 "$nested_lock_pid" 2>/dev/null; then
+		echo "nested component lock exited before acquisition" >&2
+		exit 1
+	fi
+	sleep 0.05
+done
+if [[ ! -e "$nested_lock_ready_file" ]]; then
+	echo "nested component lock was not acquired before deadline" >&2
+	exit 1
+fi
+sed -i 's/nested-component-marker-a/nested-component-marker-b/' "$source_dir/nested-child.uce"
+started_at=$(date +%s%N)
+nested_output=$(scripts/uce-cli "/$test_name/nested-parent.uce")
+elapsed_ms=$(( ($(date +%s%N) - started_at) / 1000000 ))
+wait "$nested_lock_pid"
+if [[ "$nested_output" != *"nested-component-marker-b"* ]]; then
+	echo "CLI nested component returned stale wasm: $nested_output" >&2
+	exit 1
+fi
+if (( elapsed_ms < 2000 )); then
+	echo "CLI nested component did not wait for the active rebuild (${elapsed_ms}ms)" >&2
+	exit 1
+fi
+
 # Warm every configured worker, then replace the artifact while retaining its
 # whole-second mtime. The worker cache must notice the nanosecond/ctime change.
 for _ in {1..16}; do assert_marker parent dependency-marker-d; done