From 5f265344964a2a017b968872475b11d8613884fc Mon Sep 17 00:00:00 2001
From: David Baker <dave@matrix.org>
Date: Thu, 12 Jan 2023 15:17:46 +0000
Subject: [PATCH] Use IndexedDB storage in dev mode, just without the worker

As per comment, we can't use workers in Vite dev mode. We previously
fell back to the memory store but this ends up with it working significantly
differently in dev mode to production, eg. dev mode would always start
by doing an initial sync, so old to-device messages would arrive again.

There's no need to fall all the way back to the memory store though,
we can use the IndexedDB store without the worker.
---
 src/matrix-utils.ts | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/src/matrix-utils.ts b/src/matrix-utils.ts
index 3e01d16..dc55702 100644
--- a/src/matrix-utils.ts
+++ b/src/matrix-utils.ts
@@ -94,12 +94,17 @@ export async function initClient(
 
   const storeOpts = {} as ICreateClientOpts;
 
-  if (indexedDB && localStorage && !import.meta.env.DEV) {
+  if (indexedDB && localStorage) {
     storeOpts.store = new IndexedDBStore({
       indexedDB: window.indexedDB,
       localStorage,
       dbName: SYNC_STORE_NAME,
-      workerFactory: () => new IndexedDBWorker(),
+      // We can't use the worker in dev mode because Vite simply doesn't bundle workers
+      // in dev mode: it expects them to use native modules. Ours don't, and even then only
+      // Chrome supports it. (It bundles them fine in production mode.)
+      workerFactory: import.meta.env.DEV
+        ? undefined
+        : () => new IndexedDBWorker(),
     });
   } else if (localStorage) {
     storeOpts.store = new MemoryStore({ localStorage });