From d8bfa04613ae87e6ecce254509452bc3f2ad3cb6 Mon Sep 17 00:00:00 2001
From: Nate Armstrong <nate.armstrong@eluv.io>
Date: Mon, 6 May 2024 13:59:38 -0700
Subject: [PATCH] Make copy generic over map types

---
 util/maputil/maputil.go      |  4 ++--
 util/maputil/maputil_test.go | 18 ++++++++++++++++++
 2 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/util/maputil/maputil.go b/util/maputil/maputil.go
index ec5ecad..4631d9b 100644
--- a/util/maputil/maputil.go
+++ b/util/maputil/maputil.go
@@ -75,8 +75,8 @@ func Add(m map[string]interface{}, nameValuePairs ...interface{}) map[string]int
 }
 
 // Copy creates a shallow copy of the given map.
-func Copy(m map[string]interface{}) map[string]interface{} {
-	cp := make(map[string]interface{}, len(m))
+func Copy[K comparable, T any](m map[K]T) map[K]T {
+	cp := make(map[K]T, len(m))
 	for k, v := range m {
 		cp[k] = v
 	}
diff --git a/util/maputil/maputil_test.go b/util/maputil/maputil_test.go
index 950fddd..3e90bfe 100644
--- a/util/maputil/maputil_test.go
+++ b/util/maputil/maputil_test.go
@@ -192,3 +192,21 @@ func TestCopyMSI(t *testing.T) {
 	require.Equal(t, ma2["one"], ma["one"])
 	require.Equal(t, ma2["two"], ma["two"])
 }
+
+func TestCopyGeneric(t *testing.T) {
+	msi := map[string]interface{}{
+		"un":   1,
+		"deux": "two",
+	}
+	m2 := Copy(msi)
+	require.Equal(t, msi, m2)
+
+	mis := map[int]string{
+		1: "one",
+		2: "two",
+	}
+	var m3 map[int]string
+	m3 = Copy(mis)
+	require.Equal(t, mis, m3)
+
+}