The runtime serves a bundle its module's state (novox/hq ADR 0201)

mesh/state.get, put, delete, keys and watch on the stdio channel, from the
buckets the membership issues. A watch hands the current values without
deletions, then every change, and is answered once the current values are
delivered. Refused with the reason: state not issued, a reader's write, a
value with a credential-named field — the bus alone would answer a refused
write with a timeout.

node-tools/internal/meshtest/meshtest.go

@@ -182,3 +182,15 @@ func (m *Mesh) Pending(t *testing.T, node, module string) (ackPending, notDelive
 	}
 	return uint64(info.NumAckPending), info.NumPending
 }
+
+// Bucket makes a module's state afresh as the controller does from the catalogue (novox/hq ADR 0201),
+// and answers it for writing what is there before a bundle starts.
+func (m *Mesh) Bucket(t *testing.T, name string) nats.KeyValue {
+	t.Helper()
+	_ = m.js.DeleteKeyValue(name)
+	kv, err := m.js.CreateKeyValue(&nats.KeyValueConfig{Bucket: name, History: 1, MaxValueSize: 256 * 1024})
+	if err != nil {
+		t.Fatal(err)
+	}
+	return kv
+}