feat(sdk) LinkedChunkError is a real error now.

Author: Hywan

crates/matrix-sdk/src/event_cache/linked_chunk.rs

@@ -15,6 +15,8 @@
 #![allow(dead_code)]
 
 use std::{
+    convert::Infallible,
+    error::Error,
     fmt,
     marker::PhantomData,
     ops::Not,
@@ -26,11 +28,18 @@ use std::{
 };
 
 /// Errors of [`LinkedChunk`].
-#[derive(Debug)]
+#[derive(thiserror::Error, Debug)]
 pub enum LinkedChunkError {
+    #[error("The chunk identifier is invalid: `{identifier:?}`")]
     InvalidChunkIdentifier { identifier: ChunkIdentifier },
+
+    #[error("The chunk is a gap: `{identifier:?}`")]
     ChunkIsAGap { identifier: ChunkIdentifier },
+
+    #[error("The chunk is an item: `{identifier:?}`")]
     ChunkIsItems { identifier: ChunkIdentifier },
+
+    #[error("The item index is invalid: `{index}`")]
     InvalidItemIndex { index: usize },
 }
 
@@ -1120,7 +1129,7 @@ impl<Item, Gap> LinkedChunkListener<Item, Gap> for () {
 
 #[cfg(test)]
 mod tests {
-    use std::fmt::Debug;
+    use std::{convert::Infallible, fmt::Debug};
 
     use assert_matches::assert_matches;
 
@@ -1256,7 +1265,7 @@ mod tests {
         Item: Clone + Debug + Send + Sync,
         Gap: Clone + Debug + Send + Sync,
     {
-        type Error = ();
+        type Error = Infallible;
 
         fn new_chunk_items(
             &self,
@@ -1808,7 +1817,7 @@ mod tests {
             let position_after_f =
                 Position(position_of_f.chunk_identifier(), position_of_f.index() + 1);
 
-            linked_chunk.insert_items_at(['p', 'q'], position_after_f).await?;
+            linked_chunk.insert_items_at(['p', 'q'], position_after_f)?;
             assert_items_eq!(
                 linked_chunk,
                 ['l', 'm', 'n'] ['o', 'a', 'b'] ['r', 's', 'c'] ['d', 'w', 'x'] ['y', 'z', 'e'] ['f', 'p', 'q']

crates/matrix-sdk/src/event_cache/mod.rs

@@ -215,6 +215,7 @@ impl EventCache {
                     // re-creating the `RoomEventCache` would create a new unrelated sender.
 
                     let rooms = inner.by_room.write().await;
+
                     for room in rooms.values() {
                         // Notify all the observers that we've lost track of state. (We ignore the
                         // error if there aren't any.)
@@ -761,19 +762,19 @@ impl RoomEventCacheInner {
             Some(first_event_pos) => {
                 if let Some(prev_token_gap) = prev_token {
                     room_events
-                            .insert_gap_at(prev_token_gap, first_event_pos)
-                            // SAFETY: The `first_event_pos` can only be an `Item` chunk, it's
-                            // an invariant of `LinkedChunk`. Also, it can only represent a valid
-                            // `ChunkIdentifier` as the data structure isn't modified yet.
-                            .expect("`first_event_pos` must point to a valid `Item` chunk when inserting a gap");
+                        .insert_gap_at(prev_token_gap, first_event_pos)
+                        // SAFETY: The `first_event_pos` can only be an `Item` chunk, it's
+                        // an invariant of `LinkedChunk`. Also, it can only represent a valid
+                        // `ChunkIdentifier` as the data structure isn't modified yet.
+                        .expect("`first_event_pos` must point to a valid `Item` chunk when inserting a gap");
                 }
 
                 room_events
-                        .insert_events_at(sync_events, first_event_pos)
-                        // SAFETY: The `first_event_pos` can only be an `Item` chunk, it's
-                        // an invariant of `LinkedChunk`. The chunk it points to has not been
-                        // removed.
-                        .expect("The `first_event_pos` must point to a valid `Item` chunk when inserting events");
+                    .insert_events_at(sync_events, first_event_pos)
+                    // SAFETY: The `first_event_pos` can only be an `Item` chunk, it's
+                    // an invariant of `LinkedChunk`. The chunk it points to has not been
+                    // removed.
+                    .expect("The `first_event_pos` must point to a valid `Item` chunk when inserting events");
             }
 
             // There is no first item. Let's simply push.