wip better, two separate functions

Author: gnprice

lib/model/store.dart

@@ -949,19 +949,8 @@ class UpdateMachine {
           if (_disposed) return;
 
           store.isLoading = true;
-          switch (e) {
-            case NetworkException():
-            case Server5xxException():
-            case ZulipApiException(httpStatus: 429):
-            case ZulipApiException(code: 'RATE_LIMIT_HIT'):
-              // TODO(#946) handle rate-limit errors more generally, in ApiConnection
-              break;
-
-            default:
-              rethrow;
-          }
-
-          _reportPollError(e, transient: true);
+          final shouldRetry = _triagePollRequestError(e);
+          if (!shouldRetry) rethrow;
           await (backoffMachine ??= BackoffMachine()).wait();
           if (_disposed) return;
           assert(debugLog('… Backoff wait complete, retrying poll.'));
@@ -1009,7 +998,7 @@ class UpdateMachine {
       // or an unexpected exception representing a bug in our code or the server.
       // Either way, the show must go on.  So reload server data from scratch.
 
-      _reportPollError(e, transient: false);
+      _reportPollError(e);
 
       // This disposes the store, which disposes this update machine.
       await store._globalStore._reloadPerAccount(store.accountId);
@@ -1032,15 +1021,19 @@ class UpdateMachine {
     reportErrorToUserBriefly(null);
   }
 
-  /// Report an error in [poll] to the user if appropriate,
-  /// and to the developer console in debug builds.
-  void _reportPollError(Object error, {required bool transient}) {
+  /// Sort out an error from the network request in [poll].
+  ///
+  /// If the request should be retried, this method returns true,
+  /// after reporting the error if appropriate to the user and/or developer.
+  /// Otherwise, this method returns false with no side effects.
+  bool _triagePollRequestError(Object error) {
     switch (error) {
       case NetworkException(cause: SocketException()):
         assert(debugLog('Transient error polling event queue for $store: $error\n'
             'Backing off, then will retry…'));
         // A [SocketException] is common when the app returns from sleep.
         // Don't bother the user about it.
+        return true;
 
       case NetworkException():
       case Server5xxException():
@@ -1050,7 +1043,17 @@ class UpdateMachine {
         assert(debugLog('Transient error polling event queue for $store: $error\n'
             'Backing off, then will retry…'));
         _maybeReportToUserTransientError(error);
+        return true;
+
+      default:
+        return false;
+    }
+  }
 
+  /// Report an error in [poll] to the user if appropriate,
+  /// and to the developer console in debug builds.
+  void _reportPollError(Object error) {
+    switch (error) {
       case ZulipApiException(code: 'BAD_EVENT_QUEUE_ID'):
         assert(debugLog('Lost event queue for $store.  Replacing…'));
         // The old event queue is gone, so we need a new one.  This is normal.