msglist test: Use default screen size

This size is in *physical* pixels, not logical -- so with the
tests' default device pixel ratio of 3, it corresponds to
200w267h in logical pixels, which is a very small screen.
(It's a bit over 2 inches (53mm) diagonal when converted at
160px/in, which is the nominal value for a logical pixel.)

Better to use the default size, which is somewhat more realistic.
In particular, we have a known issue (#282) that the recipient headers
suffer overflow if a stream name is long.  This tiny screen causes
that issue to appear even when a name is not very long at all;
and when we add dates to the recipient headers (#172), it would
start happening in the tests as they stand.

A handful of tests need adjustments to keep working with the new
size, mostly just to fill the message list with more messages.

Author: gnprice

lib/widgets/message_list.dart

@@ -427,7 +427,7 @@ class StreamTopicRecipientHeader extends StatelessWidget {
       child: ColoredBox(
         color: _kStreamMessageBorderColor,
         child: Row(mainAxisAlignment: MainAxisAlignment.start, children: [
-          // TODO: Long stream name will break layout; find a fix.
+          // TODO(#282): Long stream name will break layout; find a fix.
           GestureDetector(
             onTap: () => Navigator.push(context,
               MessageListPage.buildRoute(context: context,

test/widgets/message_list_test.dart

@@ -33,10 +33,6 @@ void main() {
     List<Message>? messages,
   }) async {
     addTearDown(testBinding.reset);
-    addTearDown(tester.view.resetPhysicalSize);
-
-    tester.view.physicalSize = const Size(600, 800);
-
     await testBinding.globalStore.add(eg.selfAccount, eg.initialSnapshot());
     store = await testBinding.globalStore.perAccount(eg.selfAccount.id);
     connection = store.connection as FakeApiConnection;
@@ -72,8 +68,8 @@ void main() {
 
     testWidgets('basic', (tester) async {
       await setupMessageListPage(tester, foundOldest: false,
-        messages: List.generate(30, (i) => eg.streamMessage(id: 950 + i, sender: eg.selfUser)));
-      check(itemCount(tester)).equals(30);
+        messages: List.generate(100, (i) => eg.streamMessage(id: 950 + i, sender: eg.selfUser)));
+      check(itemCount(tester)).equals(100);
 
       // Fling-scroll upward...
       await tester.fling(find.byType(MessageListPage), const Offset(0, 300), 8000);
@@ -86,13 +82,13 @@ void main() {
       await tester.pump(Duration.zero); // Allow a frame for the response to arrive.
 
       // Now we have more messages.
-      check(itemCount(tester)).equals(130);
+      check(itemCount(tester)).equals(200);
     });
 
     testWidgets('observe double-fetch glitch', (tester) async {
       await setupMessageListPage(tester, foundOldest: false,
-        messages: List.generate(30, (i) => eg.streamMessage(id: 950 + i, sender: eg.selfUser)));
-      check(itemCount(tester)).equals(30);
+        messages: List.generate(100, (i) => eg.streamMessage(id: 950 + i, sender: eg.selfUser)));
+      check(itemCount(tester)).equals(100);
 
       // Fling-scroll upward...
       await tester.fling(find.byType(MessageListPage), const Offset(0, 300), 8000);
@@ -101,17 +97,17 @@ void main() {
       // ... and we fetch more messages as we go.
       connection.prepare(json: olderResult(anchor: 950, foundOldest: false,
         messages: List.generate(100, (i) => eg.streamMessage(id: 850 + i, sender: eg.selfUser))).toJson());
-      await tester.pump(const Duration(seconds: 2));
+      await tester.pump(const Duration(milliseconds: 500));
       await tester.pump(Duration.zero);
-      check(itemCount(tester)).equals(130);
+      check(itemCount(tester)).equals(200);
 
       // But on the next frame, we promptly fetch *another* batch.
       // This is a glitch and it'd be nicer if we didn't.
       connection.prepare(json: olderResult(anchor: 850, foundOldest: false,
         messages: List.generate(100, (i) => eg.streamMessage(id: 750 + i, sender: eg.selfUser))).toJson());
       await tester.pump(const Duration(milliseconds: 1));
       await tester.pump(Duration.zero);
-      check(itemCount(tester)).equals(230);
+      check(itemCount(tester)).equals(300);
     });
   });
 
@@ -140,7 +136,7 @@ void main() {
     });
 
     testWidgets('dimension updates changes visibility', (WidgetTester tester) async {
-      await setupMessageListPage(tester, messageCount: 10);
+      await setupMessageListPage(tester, messageCount: 100);
 
       final scrollController = findMessageListScrollController(tester)!;
 
@@ -151,6 +147,7 @@ void main() {
       await tester.pump();
       check(isButtonVisible(tester)).equals(true);
 
+      addTearDown(tester.view.resetPhysicalSize);
       tester.view.physicalSize = const Size(2000, 40000);
       await tester.pump();
       // Dimension changes use NotificationListener<ScrollMetricsNotification