feat: encoding/jsonutil/jsonraw: add ObjectModify()`

Author: grokify

encoding/jsonutil/jsonraw/object.go

@@ -0,0 +1,31 @@
+package jsonutil
+
+import (
+	"encoding/json"
+)
+
+// ObjectModify creates a new byte slice, from an existing byte slice, with only the supplied field names.
+func ObjectModify(b []byte, fieldNamesInclCopy []string, fieldNameInclUpsertValues map[string]any) ([]byte, error) {
+	msa := map[string]any{}
+	err := json.Unmarshal(b, &msa)
+	if err != nil {
+		return []byte{}, err
+	}
+	if len(msa) == 0 {
+		return b, nil
+	}
+	incl := map[string]int{}
+	for _, f := range fieldNamesInclCopy {
+		incl[f]++
+	}
+	out := map[string]any{}
+	for k, v := range msa {
+		if _, ok := incl[k]; ok {
+			out[k] = v
+		}
+	}
+	for k, v := range fieldNameInclUpsertValues {
+		out[k] = v
+	}
+	return json.Marshal(out)
+}