From 4e0dab959a3645fafbd36dc4db598095cc9d8067 Mon Sep 17 00:00:00 2001
From: Michael Goldenberg <m@mgoldenberg.net>
Date: Tue, 15 Jul 2025 12:26:36 -0400
Subject: [PATCH] feat(indexeddb): add IndexedDB-backed impl for
 EventCacheStore::save_event

Signed-off-by: Michael Goldenberg <m@mgoldenberg.net>
---
 .../event_cache_store/integration_tests.rs    |  7 ++++++
 .../src/event_cache_store/mod.rs              | 22 ++++++++++++++-----
 .../src/event_cache_store/types.rs            | 10 +++++++++
 3 files changed, 33 insertions(+), 6 deletions(-)

diff --git a/crates/matrix-sdk-indexeddb/src/event_cache_store/integration_tests.rs b/crates/matrix-sdk-indexeddb/src/event_cache_store/integration_tests.rs
index 68c54ba2b..873f3f41f 100644
--- a/crates/matrix-sdk-indexeddb/src/event_cache_store/integration_tests.rs
+++ b/crates/matrix-sdk-indexeddb/src/event_cache_store/integration_tests.rs
@@ -762,6 +762,13 @@ macro_rules! event_cache_store_integration_tests {
                     get_event_cache_store().await.unwrap().into_event_cache_store();
                 event_cache_store.test_find_event().await;
             }
+
+            #[async_test]
+            async fn test_save_event() {
+                let event_cache_store =
+                    get_event_cache_store().await.unwrap().into_event_cache_store();
+                event_cache_store.test_save_event().await;
+            }
         }
     };
 }
diff --git a/crates/matrix-sdk-indexeddb/src/event_cache_store/mod.rs b/crates/matrix-sdk-indexeddb/src/event_cache_store/mod.rs
index 66a9dcff5..445020b49 100644
--- a/crates/matrix-sdk-indexeddb/src/event_cache_store/mod.rs
+++ b/crates/matrix-sdk-indexeddb/src/event_cache_store/mod.rs
@@ -31,14 +31,14 @@ use matrix_sdk_base::{
     timer,
 };
 use ruma::{events::relation::RelationType, EventId, MxcUri, OwnedEventId, RoomId};
-use tracing::{instrument, trace};
+use tracing::{error, instrument, trace};
 use web_sys::IdbTransactionMode;
 
 use crate::event_cache_store::{
     migrations::current::keys,
     serializer::IndexeddbEventCacheStoreSerializer,
     transaction::{IndexeddbEventCacheStoreTransaction, IndexeddbEventCacheStoreTransactionError},
-    types::{ChunkType, InBandEvent},
+    types::{ChunkType, InBandEvent, OutOfBandEvent},
 };
 
 mod builder;
@@ -493,10 +493,20 @@ impl_event_cache_store! {
         event: Event,
     ) -> Result<(), IndexeddbEventCacheStoreError> {
         let _timer = timer!("method");
-        self.memory_store
-            .save_event(room_id, event)
-            .await
-            .map_err(IndexeddbEventCacheStoreError::MemoryStore)
+
+        let Some(event_id) = event.event_id() else {
+            error!(%room_id, "Trying to save an event with no ID");
+            return Ok(());
+        };
+        let transaction =
+            self.transaction(&[keys::EVENTS], IdbTransactionMode::Readwrite)?;
+        let event = match transaction.get_event_by_id(room_id, &event_id).await? {
+            Some(mut inner) => inner.with_content(event),
+            None => types::Event::OutOfBand(OutOfBandEvent { content: event, position: () }),
+        };
+        transaction.put_event(room_id, &event).await?;
+        transaction.commit().await?;
+        Ok(())
     }
 
     #[instrument(skip_all)]
diff --git a/crates/matrix-sdk-indexeddb/src/event_cache_store/types.rs b/crates/matrix-sdk-indexeddb/src/event_cache_store/types.rs
index d2f90f76c..3ef36eccc 100644
--- a/crates/matrix-sdk-indexeddb/src/event_cache_store/types.rs
+++ b/crates/matrix-sdk-indexeddb/src/event_cache_store/types.rs
@@ -94,6 +94,16 @@ impl Event {
             Event::OutOfBand(e) => e.relation(),
         }
     }
+
+    /// Sets the content of the underlying [`GenericEvent`] and returns
+    /// the mutated [`Event`]
+    pub fn with_content(mut self, content: TimelineEvent) -> Self {
+        match self {
+            Event::InBand(ref mut i) => i.content = content,
+            Event::OutOfBand(ref mut o) => o.content = content,
+        }
+        self
+    }
 }
 
 /// A generic representation of an