chore: add more tests (#3338)

core/search/tree_test.go

@@ -11,7 +11,7 @@ import (
 
 type mockedRoute struct {
 	route string
-	value int
+	value any
 }
 
 func TestSearch(t *testing.T) {
@@ -187,6 +187,12 @@ func TestSearchInvalidItem(t *testing.T) {
 	assert.Equal(t, errEmptyItem, err)
 }
 
+func TestSearchInvalidState(t *testing.T) {
+	nd := newNode("0")
+	nd.children[0]["1"] = nil
+	assert.Error(t, add(nd, "1/2", "2"))
+}
+
 func BenchmarkSearchTree(b *testing.B) {
 	const (
 		avgLen  = 1000