msglist test: Make new DmRecpientHeader group; move two tests into it

A counterpart to the StreamMessageRecipientHeader group.

Author: chrisbobbe

test/widgets/message_list_test.dart

@@ -368,35 +368,37 @@ void main() {
       });
     });
 
-    testWidgets('show names on DMs', (tester) async {
-      final zulipLocalizations = GlobalLocalizations.zulipLocalizations;
-      await setupMessageListPage(tester, messages: [
-        eg.dmMessage(from: eg.selfUser, to: []),
-        eg.dmMessage(from: eg.otherUser, to: [eg.selfUser]),
-        eg.dmMessage(from: eg.thirdUser, to: [eg.selfUser, eg.otherUser]),
-      ]);
-      store.addUser(eg.otherUser);
-      store.addUser(eg.thirdUser);
-      await tester.pump();
-      tester.widget(find.text(zulipLocalizations.messageListGroupYouWithYourself));
-      tester.widget(find.text(zulipLocalizations.messageListGroupYouAndOthers(
-        eg.otherUser.fullName)));
-      tester.widget(find.text(zulipLocalizations.messageListGroupYouAndOthers(
-        "${eg.otherUser.fullName}, ${eg.thirdUser.fullName}")));
-    });
+    group('DmRecipientHeader', () {
+      testWidgets('show names', (tester) async {
+        final zulipLocalizations = GlobalLocalizations.zulipLocalizations;
+        await setupMessageListPage(tester, messages: [
+          eg.dmMessage(from: eg.selfUser, to: []),
+          eg.dmMessage(from: eg.otherUser, to: [eg.selfUser]),
+          eg.dmMessage(from: eg.thirdUser, to: [eg.selfUser, eg.otherUser]),
+        ]);
+        store.addUser(eg.otherUser);
+        store.addUser(eg.thirdUser);
+        await tester.pump();
+        tester.widget(find.text(zulipLocalizations.messageListGroupYouWithYourself));
+        tester.widget(find.text(zulipLocalizations.messageListGroupYouAndOthers(
+          eg.otherUser.fullName)));
+        tester.widget(find.text(zulipLocalizations.messageListGroupYouAndOthers(
+          "${eg.otherUser.fullName}, ${eg.thirdUser.fullName}")));
+      });
 
-    testWidgets('show names on DMs: smoothly handle unknown users', (tester) async {
-      final zulipLocalizations = GlobalLocalizations.zulipLocalizations;
-      await setupMessageListPage(tester, messages: [
-        eg.dmMessage(from: eg.otherUser, to: [eg.selfUser]),
-        eg.dmMessage(from: eg.thirdUser, to: [eg.selfUser, eg.otherUser]),
-      ]);
-      store.addUser(eg.thirdUser);
-      await tester.pump();
-      tester.widget(find.text(zulipLocalizations.messageListGroupYouAndOthers(
-        zulipLocalizations.unknownUserName)));
-      tester.widget(find.text(zulipLocalizations.messageListGroupYouAndOthers(
-        "${zulipLocalizations.unknownUserName}, ${eg.thirdUser.fullName}")));
+      testWidgets('show names: smoothly handle unknown users', (tester) async {
+        final zulipLocalizations = GlobalLocalizations.zulipLocalizations;
+        await setupMessageListPage(tester, messages: [
+          eg.dmMessage(from: eg.otherUser, to: [eg.selfUser]),
+          eg.dmMessage(from: eg.thirdUser, to: [eg.selfUser, eg.otherUser]),
+        ]);
+        store.addUser(eg.thirdUser);
+        await tester.pump();
+        tester.widget(find.text(zulipLocalizations.messageListGroupYouAndOthers(
+          zulipLocalizations.unknownUserName)));
+        tester.widget(find.text(zulipLocalizations.messageListGroupYouAndOthers(
+          "${zulipLocalizations.unknownUserName}, ${eg.thirdUser.fullName}")));
+      });
     });
 
     testWidgets('show dates', (tester) async {