Add bson clone

struct.go

@@ -76,7 +76,7 @@ func MapMerge[T ~map[string]any](maps...T) T {
 }
 
 // StructMustTomap given any struct return the equivalent map[string]any or nil.
-// Will never throw.
+// Will never throw. Will also work for map[string]any.
 func StructMustToMap(data any) map[string]any {
 	b, err := json.Marshal(data)
 	if err != nil {
@@ -164,6 +164,54 @@ func StructToMapRecursive(obj any) any {
 	}
 }
 
+func BsonClone(m map[string]any) map[string]any {
+	if m == nil {
+		return nil
+	}
+
+	out := make(map[string]any, len(m))
+
+	for k, v := range m {
+		out[k] = deepCopy(v)
+	}
+
+	return out
+}
+
+func deepCopy(v any) any {
+	switch val := v.(type) {
+	case bson.M:
+		return BsonClone(map[string]any(val))
+	case bson.A:
+		arr := make([]any, len(val))
+		for i, item := range val {
+			arr[i] = deepCopy(item)
+		}
+		return arr
+	case bson.D:
+		d := make(bson.D, len(val))
+		for i, elem := range val {
+			d[i] = bson.E{
+				Key:   elem.Key,
+				Value: deepCopy(elem.Value),
+			}
+		}
+		return d
+	case map[string]any: // bson.M
+		return BsonClone(val)
+	case []any: // bson.A
+		arr := make([]any, len(val))
+		for i, item := range val {
+			arr[i] = deepCopy(item)
+		}
+		return arr
+
+	default:
+		// primitives (string, int, bool, etc.)
+		return val
+	}
+}
+
 func BsonDGetAny(d bson.D, key string) (any, bool) {
 	for _, e := range d {
 		if e.Key == key {

struct_test.go

@@ -1,6 +1,7 @@
 package commons
 
 import (
+  "fmt"
   "testing"
 )
 
@@ -308,3 +309,30 @@ func TestMapMerge(t *testing.T) {
     t.Fatalf("Merged map should have lenght 4 not %d", len(m))
   }
 }
+
+func TestBsonClone(t *testing.T) {
+  orig := map[string]any{
+    "name": "Kolias",
+    "age": int32(56),
+    "salary": int64(100000000),
+    "meta": map[string]any{
+      "num1": int32(110),
+    },
+  }
+
+  clone := BsonClone(orig)
+
+  if "int32" != fmt.Sprintf("%T", clone["age"]) {
+    t.Fatalf("int32 should map to int32")
+  }
+
+  if "int64" != fmt.Sprintf("%T", clone["salary"]) {
+    t.Fatalf("int64 should map to int64")
+  }
+
+  meta := clone["meta"].(map[string]any)
+
+  if "int32" != fmt.Sprintf("%T", meta["num1"]) {
+    t.Fatalf("netsted type should have been int32")
+  }
+}