consul/state: test for index modification during deletes

consul/state/state_store.go

@@ -40,6 +40,26 @@ func NewStateStore(logOutput io.Writer) (*StateStore, error) {
 	return s, nil
 }
 
+// maxIndex is a helper used to retrieve the highest known index
+// amongst a set of tables in the db.
+func (s *StateStore) maxIndex(tables ...string) uint64 {
+	tx := s.db.Txn(false)
+	defer tx.Abort()
+
+	var lindex uint64
+	for _, table := range tables {
+		ti, err := tx.First("index", "id", table)
+		if err != nil {
+			panic(fmt.Sprintf("unknown index: %s", table))
+		}
+		idx := ti.(*IndexEntry).Value
+		if idx > lindex {
+			lindex = idx
+		}
+	}
+	return lindex
+}
+
 // EnsureNode is used to upsert node registration or modification.
 func (s *StateStore) EnsureNode(idx uint64, node *structs.Node) error {
 	tx := s.db.Txn(true)

consul/state/state_store_test.go

@@ -143,10 +143,13 @@ func TestStateStore_DeleteNode(t *testing.T) {
 		t.Fatalf("err: %s", err)
 	}
 
-	// The node is now gone
+	// The node is now gone and the index was updated
 	if n, err := s.GetNode("node1"); err != nil || n != nil {
 		t.Fatalf("bad: %#v (err: %#v)", node, err)
 	}
+	if idx := s.maxIndex("nodes"); idx != 2 {
+		t.Fatalf("bad index: %d", idx)
+	}
 }
 
 func TestStateStore_EnsureService_NodeServices(t *testing.T) {
@@ -262,9 +265,12 @@ func TestStateStore_DeleteNodeService(t *testing.T) {
 		t.Fatalf("err: %s", err)
 	}
 
-	// The service doesn't exist.
+	// The service doesn't exist and the index was updated
 	ns, err = s.NodeServices("node1")
 	if err != nil || ns == nil || len(ns.Services) != 0 {
 		t.Fatalf("bad: %#v (err: %#v)", ns, err)
 	}
+	if idx := s.maxIndex("services"); idx != 3 {
+		t.Fatalf("bad index: %d", idx)
+	}
 }