Reuse json tags while decoding map to struct

post/post.go

@@ -128,7 +128,14 @@ func Jf2ToPost(jf2 microformats.Jf2) (Post, error) {
 		return post, err
 	}
 	normalized["kind"] = getPostKind(normalized)
-	if err = mapstructure.Decode(normalized, &post); err != nil {
+	decoder, err := mapstructure.NewDecoder(&mapstructure.DecoderConfig{
+		TagName: "json",
+		Result:  &post,
+	})
+	if err != nil {
+		return post, err
+	}
+	if err = decoder.Decode(normalized); err != nil {
 		return post, fmt.Errorf("%w: %s", ErrorInvalidPost, err.Error())
 	}
 	validate := validator.New()