refactor(widget): Use clearer types for processing read state response

Author: robintown

crates/matrix-sdk/src/widget/machine/mod.rs

@@ -660,29 +660,26 @@ impl WidgetMachine {
     /// [`NotifyStateUpdate`] action.
     fn process_read_initial_state_response(
         &mut self,
-        events: Result<Vec<Raw<AnyStateEvent>>, Error>,
-    ) -> Vec<Action> {
+        events: Vec<Raw<AnyStateEvent>>,
+    ) -> Option<Vec<Action>> {
         // Pull the updates struct out of the machine temporarily so that we can match
         // on it in one place, mutate it, and still be able to call
         // `send_to_widget_request` later in this block (which borrows the machine
         // mutably)
         match self.pending_state_updates.take() {
             None => {
                 error!("Initial state updates must only be set to `None` once all requests are complete; dropping state response");
-                Vec::new()
+                None
             }
 
             Some(mut updates) => {
-                updates.initial_state.push(events.unwrap_or_else(|e| {
-                    error!("Reading initial room state failed: {e}");
-                    Vec::new()
-                }));
+                updates.initial_state.push(events);
 
                 if updates.initial_state.len() != updates.request_count {
                     // Not all of the initial state requests have completed yet; put the updates
                     // struct back so we can continue accumulating the initial state.
                     self.pending_state_updates = Some(updates);
-                    return Vec::new();
+                    return None;
                 }
 
                 // The initial state is complete; combine the data and push it to the widget in
@@ -701,7 +698,7 @@ impl WidgetMachine {
                     .map(|state| self.send_state_update(state));
 
                 // The postponed updates should come after the initial update
-                initial.into_iter().chain(postponed.flatten()).collect()
+                Some(initial.into_iter().chain(postponed.flatten()).collect())
             }
         }
     }
@@ -771,7 +768,14 @@ impl WidgetMachine {
             })
             .map(|(request, action)| {
                 request.add_response_handler(move |result, machine| {
-                    machine.process_read_initial_state_response(result)
+                    machine
+                        .process_read_initial_state_response(result.unwrap_or_else(|e| {
+                            error!("Reading initial room state failed: {e}");
+                            // Pretend that we just got an empty response so the initial state
+                            // update won't be completely blocked on this one bit of missing data
+                            Vec::new()
+                        }))
+                        .unwrap_or_default()
                 });
                 action
             })