fixup lint errors

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

util/reflect/reflect.go

@@ -91,7 +91,7 @@ func Merge(dst interface{}, mp map[string]interface{}, opts ...Option) error {
 	}
 
 	if mapper, ok := dst.(map[string]interface{}); ok {
-		dst = mergeMap(mapper, mp, 0)
+		mergeMap(mapper, mp, 0)
 		return nil
 	}
 

util/reflect/reflect_test.go

@@ -1,9 +1,38 @@
 package reflect
 
 import (
+	"fmt"
 	"testing"
 )
 
+func TestMergeMapStringInterface(t *testing.T) {
+	var dst interface{} //nolint:gosimple
+	dst = map[string]interface{}{
+		"xx": 11,
+	}
+
+	src := map[string]interface{}{
+		"zz": "aa",
+	}
+
+	if err := Merge(dst, src); err != nil {
+		t.Fatal(err)
+	}
+
+	mp, ok := dst.(map[string]interface{})
+	if !ok || mp == nil {
+		t.Fatalf("xxx %#+v\n", dst)
+	}
+
+	if fmt.Sprintf("%v", mp["xx"]) != "11" {
+		t.Fatalf("xxx zzzz %#+v", mp)
+	}
+
+	if fmt.Sprintf("%v", mp["zz"]) != "aa" {
+		t.Fatalf("xxx zzzz %#+v", mp)
+	}
+}
+
 func TestMergeMap(t *testing.T) {
 	src := map[string]interface{}{
 		"skey1": "sval1",