useLiveQuery losing items reference

[mpirescarvalho]

When using Dexie's immutable cache and useLiveQuery, unchanged items do not retain their references under certain conditions, specifically when using .reverse() or when updating a single item within a transaction.

• Using .reverse():

const db = new Dexie("database", {
  cache: "immutable",
});

// Always gives a new reference
const items = useLiveQuery(async () => {
  const items = await db.items2.reverse().toArray();
  return items;
});

// Keeps references for unchanged items
const items = useLiveQuery(async () => {
  const items = await db.items.toArray();
  return [].concat(items).reverse();
});

// Later...
await db.items2.update(item.id, { isActive: !item.isActive });

In the first example, using .reverse() directly on the query results in new references being created, even if the items themselves haven't changed. Conversely, reversing an array after retrieval preserves the references for unchanged items.

• Using Transactions:

// useLiveQuery will refresh references even without using .reverse()
await db.transaction("rw", item2 ? db.items2 : db.items, async () => {
  await db.items.update(item.id, { isActive: !item.isActive });
});
When updating a single item within a transaction, references are lost, resulting in new references for all items in the query, despite only one item being updated.

Expected Behavior:

Unchanged items should retain their references to avoid unecessary rerenders.

Reproducible Example: (open console)
CodeSandbox link