action_sheet test: Check "Subscribe" button absent when no content access

This tests the change in cf83c9e / zulip#1822.

Author: chrisbobbe

test/model/test_store.dart

@@ -319,6 +319,19 @@ extension PerAccountStoreTestExtension on PerAccountStore {
     await handleEvent(ChannelCreateEvent(id: 1, streams: streams));
   }
 
+  Future<void> updateChannel(
+    int channelId,
+    ChannelPropertyName property,
+    Object? value,
+  ) async {
+    await handleEvent(ChannelUpdateEvent(
+      id: 1,
+      streamId: channelId,
+      name: 'some channel name', // (not true, of course, but that's fine)
+      property: property,
+      value: value));
+  }
+
   Future<void> addSubscription(Subscription subscription) async {
     await addSubscriptions([subscription]);
   }

test/widgets/action_sheet_test.dart

@@ -341,14 +341,30 @@ void main() {
         await tester.pump(); // [MenuItemButton.onPressed] called in a post-frame callback: flutter/flutter@e4a39fa2e
       }
 
-      testWidgets('channel not subscribed', (tester) async {
+      testWidgets('channel not subscribed, with content access', (tester) async {
         await prepare();
         final narrow = ChannelNarrow(someChannel.streamId);
         await store.removeSubscription(narrow.streamId);
+        check(store.selfHasContentAccess(someChannel)).isTrue();
         await showFromMsglistAppBar(tester, narrow: narrow);
         checkButton('Subscribe');
       });
 
+      testWidgets('channel not subscribed, without content access', (tester) async {
+        final privateChannel = eg.stream(inviteOnly: true);
+        await prepare();
+        await store.addStream(privateChannel);
+        await store.updateChannel(privateChannel.streamId,
+          ChannelPropertyName.canSubscribeGroup, eg.groupSetting(members: []));
+        await store.updateChannel(privateChannel.streamId,
+          ChannelPropertyName.canAddSubscribersGroup, eg.groupSetting(members: []));
+        final narrow = ChannelNarrow(privateChannel.streamId);
+        check(store.selfHasContentAccess(privateChannel)).isFalse();
+        await showFromMsglistAppBar(tester,
+          channel: privateChannel, narrow: narrow);
+        checkNoButton('Subscribe');
+      });
+
       testWidgets('channel subscribed', (tester) async {
         await prepare();
         final narrow = ChannelNarrow(someChannel.streamId);