From f7df0ebf97012e4ea440e934ccff14ab38e1a834 Mon Sep 17 00:00:00 2001
From: Benjamin Bouvier <benjamin@bouvier.cc>
Date: Tue, 1 Jul 2025 16:15:24 +0200
Subject: [PATCH] refactor(event cache): change order of parameters in
 `replace_gap`

"Replace *this* gap with *these* events" read more natural to me than
"replace with *these* events *this* gap".
---
 crates/matrix-sdk/src/event_cache/room/events.rs | 13 +++++++------
 crates/matrix-sdk/src/event_cache/room/mod.rs    |  2 +-
 2 files changed, 8 insertions(+), 7 deletions(-)

diff --git a/crates/matrix-sdk/src/event_cache/room/events.rs b/crates/matrix-sdk/src/event_cache/room/events.rs
index a0989e816..50f6a4ed1 100644
--- a/crates/matrix-sdk/src/event_cache/room/events.rs
+++ b/crates/matrix-sdk/src/event_cache/room/events.rs
@@ -136,10 +136,11 @@ impl EventLinkedChunk {
     /// `Chunk` that contains the `items`.
     pub fn replace_gap_at(
         &mut self,
-        events: Vec<Event>,
         gap_identifier: ChunkIdentifier,
+        events: Vec<Event>,
     ) -> Result<Option<Position>, Error> {
-        // As an optimization, we'll remove the empty chunk if it's a gap.
+        // As an optimization, we'll remove the chunk if it's a gap that would be
+        // replaced with no events.
         //
         // However, our linked chunk requires that it includes at least one chunk in the
         // in-memory representation. We could tweak this invariant, but in the
@@ -602,12 +603,12 @@ mod tests {
         linked_chunk.push_events([event_0]);
         linked_chunk.push_gap(Gap { prev_token: "hello".to_owned() });
 
-        let chunk_identifier_of_gap = linked_chunk
+        let gap_chunk_id = linked_chunk
             .chunks()
             .find_map(|chunk| chunk.is_gap().then_some(chunk.identifier()))
             .unwrap();
 
-        linked_chunk.replace_gap_at(vec![event_1, event_2], chunk_identifier_of_gap).unwrap();
+        linked_chunk.replace_gap_at(gap_chunk_id, vec![event_1, event_2]).unwrap();
 
         assert_events_eq!(
             linked_chunk.events(),
@@ -651,7 +652,7 @@ mod tests {
             .unwrap();
 
         // The next insert position is the next chunk's start.
-        let pos = linked_chunk.replace_gap_at(vec![], first_gap_id).unwrap();
+        let pos = linked_chunk.replace_gap_at(first_gap_id, vec![]).unwrap();
         assert_eq!(pos, Some(Position::new(ChunkIdentifier::new(2), 0)));
 
         // Remove the second gap.
@@ -661,7 +662,7 @@ mod tests {
             .unwrap();
 
         // No next insert position.
-        let pos = linked_chunk.replace_gap_at(vec![], second_gap_id).unwrap();
+        let pos = linked_chunk.replace_gap_at(second_gap_id, vec![]).unwrap();
         assert!(pos.is_none());
     }
 
diff --git a/crates/matrix-sdk/src/event_cache/room/mod.rs b/crates/matrix-sdk/src/event_cache/room/mod.rs
index 1e025ff9b..1f2b0f9c6 100644
--- a/crates/matrix-sdk/src/event_cache/room/mod.rs
+++ b/crates/matrix-sdk/src/event_cache/room/mod.rs
@@ -1654,7 +1654,7 @@ mod private {
                 // the underlying gap, if the conditions are favorable to
                 // us.
                 self.room_linked_chunk
-                    .replace_gap_at(reversed_events.clone(), gap_id)
+                    .replace_gap_at(gap_id, reversed_events.clone())
                     .expect("gap_identifier is a valid chunk id we read previously")
             } else if let Some(pos) = first_event_pos {
                 // No prior gap, but we had some events: assume we need to prepend events