Test and fix edge cases in map args.

v2alpha/soap/envelope/envelope.go

@@ -60,6 +60,8 @@ func NewSendAction(serviceType, actionName string, args any) *Action {
 	}
 }
 
+var stringType = reflect.TypeOf("")
+
 var _ xml.Marshaler = &Action{}
 
 // MarshalXML implements `xml.Marshaller`.
@@ -94,8 +96,7 @@ func (a *Action) MarshalXML(e *xml.Encoder, start xml.StartElement) error {
 		iter := v.MapRange()
 		for iter.Next() {
 			k := iter.Key()
-			// TODO: does this support string newtypes? convert?
-			ks := k.Interface().(string)
+			ks := k.Convert(stringType).Interface().(string)
 			v := iter.Value()
 			ke := xml.StartElement{Name: xml.Name{Local: ks}}
 			if err := e.EncodeElement(v.Interface(), ke); err != nil {

v2alpha/soap/envelope/envelope_test.go

@@ -10,6 +10,7 @@ import (
 	"testing"
 
 	"github.com/google/go-cmp/cmp"
+	"github.com/huin/goupnp/v2alpha/soap/types"
 )
 
 type testStructArgs struct {
@@ -17,6 +18,8 @@ type testStructArgs struct {
 	Bar string
 }
 
+type newString string
+
 // TestWriteRead tests the round-trip of writing an envelope and reading it back.
 func TestWriteRead(t *testing.T) {
 	tests := []struct {
@@ -33,13 +36,29 @@ func TestWriteRead(t *testing.T) {
 			&testStructArgs{},
 		},
 		{
-			"map",
+			"mapString",
 			map[string]string{
 				"Foo": "foo-1",
 				"Bar": "bar-2",
 			},
 			map[string]string{},
 		},
+		{
+			"mapUI2",
+			map[string]types.UI2{
+				"Foo": 1,
+				"Bar": 2,
+			},
+			map[string]types.UI2{},
+		},
+		{
+			"mapNewStringKey",
+			map[newString]string{
+				"Foo": "foo-1",
+				"Bar": "bar-2",
+			},
+			map[newString]string{},
+		},
 	}
 
 	for _, test := range tests {
@@ -52,7 +71,6 @@ func TestWriteRead(t *testing.T) {
 			if err != nil {
 				t.Fatalf("Write want success, got err=%v", err)
 			}
-			t.Logf("Encoded envelope:\n%v", buf)
 
 			actionOut := NewRecvAction(test.argsOut)
 
@@ -67,6 +85,9 @@ func TestWriteRead(t *testing.T) {
 			if diff := cmp.Diff(test.argsIn, test.argsOut); diff != "" {
 				t.Errorf("\nwant argsOut=%+v\ngot  %+v\ndiff:\n%s", test.argsIn, test.argsOut, diff)
 			}
+			if t.Failed() {
+				t.Logf("Encoded envelope:\n%v", buf)
+			}
 		})
 	}
 }