action_sheet test [nfc]: Share store as a late variable

These tests are all already relying on the detail that the
setupToMessageActionSheet helper uses `eg.selfAccount` for the
account.  Better to encapsulate that detail, and have them rely
on it giving the test cases a reference to the store directly.

Author: gnprice

test/widgets/action_sheet_test.dart

@@ -44,6 +44,7 @@ GetMessagesResult _getMessagesResult(Message message) {
   );
 }
 
+late PerAccountStore store;
 late FakeApiConnection connection;
 
 /// Simulates loading a [MessageListPage] and long-pressing on [message].
@@ -54,7 +55,7 @@ Future<void> setupToMessageActionSheet(WidgetTester tester, {
   addTearDown(testBinding.reset);
 
   await testBinding.globalStore.add(eg.selfAccount, eg.initialSnapshot());
-  final store = await testBinding.globalStore.perAccount(eg.selfAccount.id);
+  store = await testBinding.globalStore.perAccount(eg.selfAccount.id);
   await store.addUser(eg.user(userId: message.senderId));
   if (message is StreamMessage) {
     final stream = eg.stream(streamId: message.streamId);
@@ -111,9 +112,7 @@ void main() {
     testWidgets('success', (tester) async {
       final message = eg.streamMessage();
       await setupToMessageActionSheet(tester, message: message, narrow: TopicNarrow.ofMessage(message));
-      final store = await testBinding.globalStore.perAccount(eg.selfAccount.id);
 
-      final connection = store.connection as FakeApiConnection;
       connection.prepare(json: {});
       await tapButton(tester);
       await tester.pump(Duration.zero);
@@ -131,9 +130,6 @@ void main() {
     testWidgets('request has an error', (tester) async {
       final message = eg.streamMessage();
       await setupToMessageActionSheet(tester, message: message, narrow: TopicNarrow.ofMessage(message));
-      final store = await testBinding.globalStore.perAccount(eg.selfAccount.id);
-
-      final connection = store.connection as FakeApiConnection;
 
       connection.prepare(httpStatus: 400, json: {
         'code': 'BAD_REQUEST',
@@ -165,9 +161,7 @@ void main() {
     testWidgets('star success', (tester) async {
       final message = eg.streamMessage(flags: []);
       await setupToMessageActionSheet(tester, message: message, narrow: TopicNarrow.ofMessage(message));
-      final store = await testBinding.globalStore.perAccount(eg.selfAccount.id);
 
-      final connection = store.connection as FakeApiConnection;
       connection.prepare(json: {});
       await tapButton(tester);
       await tester.pump(Duration.zero);
@@ -185,9 +179,7 @@ void main() {
     testWidgets('unstar success', (tester) async {
       final message = eg.streamMessage(flags: [MessageFlag.starred]);
       await setupToMessageActionSheet(tester, message: message, narrow: TopicNarrow.ofMessage(message));
-      final store = await testBinding.globalStore.perAccount(eg.selfAccount.id);
 
-      final connection = store.connection as FakeApiConnection;
       connection.prepare(json: {});
       await tapButton(tester, starred: true);
       await tester.pump(Duration.zero);
@@ -205,11 +197,8 @@ void main() {
     testWidgets('star request has an error', (tester) async {
       final message = eg.streamMessage(flags: []);
       await setupToMessageActionSheet(tester, message: message, narrow: TopicNarrow.ofMessage(message));
-      final store = await testBinding.globalStore.perAccount(eg.selfAccount.id);
       final zulipLocalizations = GlobalLocalizations.zulipLocalizations;
 
-      final connection = store.connection as FakeApiConnection;
-
       connection.prepare(httpStatus: 400, json: {
         'code': 'BAD_REQUEST',
         'msg': 'Invalid message(s)',
@@ -226,11 +215,8 @@ void main() {
     testWidgets('unstar request has an error', (tester) async {
       final message = eg.streamMessage(flags: [MessageFlag.starred]);
       await setupToMessageActionSheet(tester, message: message, narrow: TopicNarrow.ofMessage(message));
-      final store = await testBinding.globalStore.perAccount(eg.selfAccount.id);
       final zulipLocalizations = GlobalLocalizations.zulipLocalizations;
 
-      final connection = store.connection as FakeApiConnection;
-
       connection.prepare(httpStatus: 400, json: {
         'code': 'BAD_REQUEST',
         'msg': 'Invalid message(s)',
@@ -297,7 +283,6 @@ void main() {
     testWidgets('in channel narrow', (tester) async {
       final message = eg.streamMessage();
       await setupToMessageActionSheet(tester, message: message, narrow: ChannelNarrow(message.streamId));
-      final store = await testBinding.globalStore.perAccount(eg.selfAccount.id);
 
       final composeBoxController = findComposeBoxController(tester)!;
       final contentController = composeBoxController.contentController;
@@ -321,7 +306,6 @@ void main() {
     testWidgets('in topic narrow', (tester) async {
       final message = eg.streamMessage();
       await setupToMessageActionSheet(tester, message: message, narrow: TopicNarrow.ofMessage(message));
-      final store = await testBinding.globalStore.perAccount(eg.selfAccount.id);
 
       final composeBoxController = findComposeBoxController(tester)!;
       final contentController = composeBoxController.contentController;
@@ -340,7 +324,6 @@ void main() {
       final message = eg.dmMessage(from: eg.selfUser, to: [eg.otherUser]);
       await setupToMessageActionSheet(tester,
         message: message, narrow: DmNarrow.ofMessage(message, selfUserId: eg.selfUser.userId));
-      final store = await testBinding.globalStore.perAccount(eg.selfAccount.id);
 
       final composeBoxController = findComposeBoxController(tester)!;
       final contentController = composeBoxController.contentController;
@@ -358,7 +341,6 @@ void main() {
     testWidgets('request has an error', (tester) async {
       final message = eg.streamMessage();
       await setupToMessageActionSheet(tester, message: message, narrow: TopicNarrow.ofMessage(message));
-      final store = await testBinding.globalStore.perAccount(eg.selfAccount.id);
 
       final composeBoxController = findComposeBoxController(tester)!;
       final contentController = composeBoxController.contentController;
@@ -454,7 +436,6 @@ void main() {
         // Get the action sheet fully deployed while the old narrow applies.
         await tester.pumpAndSettle();
 
-        final store = await testBinding.globalStore.perAccount(eg.selfAccount.id);
         final newStream = eg.stream();
         const newTopic = 'other topic';
         // This result isn't quite realistic for this request: it should get
@@ -517,7 +498,6 @@ void main() {
     testWidgets('success', (tester) async {
       final message = eg.streamMessage();
       await setupToMessageActionSheet(tester, message: message, narrow: TopicNarrow.ofMessage(message));
-      final store = await testBinding.globalStore.perAccount(eg.selfAccount.id);
 
       prepareRawContentResponseSuccess(store, message: message, rawContent: 'Hello world');
       await tapCopyMessageTextButton(tester);
@@ -531,7 +511,6 @@ void main() {
 
       final message = eg.streamMessage();
       await setupToMessageActionSheet(tester, message: message, narrow: TopicNarrow.ofMessage(message));
-      final store = await testBinding.globalStore.perAccount(eg.selfAccount.id);
 
       // Make the request take a bit of time to complete…
       prepareRawContentResponseSuccess(store, message: message, rawContent: 'Hello world',
@@ -553,7 +532,6 @@ void main() {
     testWidgets('request has an error', (tester) async {
       final message = eg.streamMessage();
       await setupToMessageActionSheet(tester, message: message, narrow: TopicNarrow.ofMessage(message));
-      final store = await testBinding.globalStore.perAccount(eg.selfAccount.id);
 
       prepareRawContentResponseError(store);
       await tapCopyMessageTextButton(tester);
@@ -585,7 +563,6 @@ void main() {
       final message = eg.streamMessage();
       final narrow = TopicNarrow.ofMessage(message);
       await setupToMessageActionSheet(tester, message: message, narrow: narrow);
-      final store = await testBinding.globalStore.perAccount(eg.selfAccount.id);
 
       await tapCopyMessageLinkButton(tester);
       await tester.pump(Duration.zero);
@@ -615,7 +592,6 @@ void main() {
       final mockSharePlus = setupMockSharePlus();
       final message = eg.streamMessage();
       await setupToMessageActionSheet(tester, message: message, narrow: TopicNarrow.ofMessage(message));
-      final store = await testBinding.globalStore.perAccount(eg.selfAccount.id);
 
       prepareRawContentResponseSuccess(store, message: message, rawContent: 'Hello world');
       await tapShareButton(tester);
@@ -627,7 +603,6 @@ void main() {
       final mockSharePlus = setupMockSharePlus();
       final message = eg.streamMessage();
       await setupToMessageActionSheet(tester, message: message, narrow: TopicNarrow.ofMessage(message));
-      final store = await testBinding.globalStore.perAccount(eg.selfAccount.id);
 
       prepareRawContentResponseSuccess(store, message: message, rawContent: 'Hello world');
       mockSharePlus.resultString = 'dev.fluttercommunity.plus/share/unavailable';
@@ -643,7 +618,6 @@ void main() {
       final mockSharePlus = setupMockSharePlus();
       final message = eg.streamMessage();
       await setupToMessageActionSheet(tester, message: message, narrow: TopicNarrow.ofMessage(message));
-      final store = await testBinding.globalStore.perAccount(eg.selfAccount.id);
 
       prepareRawContentResponseError(store);
       await tapShareButton(tester);