From 55de9c34e8c16836e3a611bd42721e4a899db04f Mon Sep 17 00:00:00 2001
From: George Suntres <gsuntres@pm.me>
Date: Wed, 22 Apr 2026 10:00:02 -0400
Subject: [PATCH] Add MapMerge

---
 struct.go      | 15 +++++++++++++++
 struct_test.go | 21 +++++++++++++++++----
 2 files changed, 32 insertions(+), 4 deletions(-)

diff --git a/struct.go b/struct.go
index 8177797..557cd26 100644
--- a/struct.go
+++ b/struct.go
@@ -43,6 +43,21 @@ func StructHasProperty(value interface{}, name string) bool {
 	return has
 }
 
+// MapMerge merges maps into one.
+func MapMerge[T ~map[string]any](maps...T) T {
+	out := make(T)
+
+	for _, m := range maps {
+		if m != nil {
+			for k, v := range m {
+				out[k] = v
+			}	
+		}		
+	}
+
+	return out
+}
+
 // StructMustTomap given any struct return the equivalent map[string]any or nil.
 // Will never throw.
 func StructMustToMap(data any) map[string]any {
diff --git a/struct_test.go b/struct_test.go
index 152fbc0..1878553 100644
--- a/struct_test.go
+++ b/struct_test.go
@@ -94,8 +94,6 @@ func TestStructToMapRecursive(t *testing.T) {
     default:
       t.Fatal("is not map")
   }
-
-
 }
 
 func TestMapToStruct(t *testing.T) {
@@ -267,7 +265,6 @@ func TestStructHasBsonName_False(t *testing.T) {
 }
 
 func TestCopyMatching(t *testing.T) {
-
   type O struct {
     Name string
     Age int
@@ -293,5 +290,21 @@ func TestCopyMatching(t *testing.T) {
   if to.Name != "Nick" && to.Age != 15 && to.Active != true {
     t.Fatalf("Failed to copy matching fields to %v", to)
   }
-
 }
+
+func TestMapMerge(t *testing.T) {
+  m1 := map[string]any{
+    "a": "va",
+    "b": "vb",
+  }
+  m2 := map[string]any{
+    "c": "vc",
+    "d": "vd",
+  }
+
+  m := MapMerge(m1, m2)
+
+  if len(m) != 4 {
+    t.Fatalf("Merged map should have lenght 4 not %d", len(m))
+  }
+}
\ No newline at end of file