refactor: Fetch service inject asynchronously

Since we don't plan to shim any APIs that must be present immediately
when the service loads, we might as well switch to asynchronous IPC for
fetching the script to inject into the main world.

1 files changed, 4 insertions, 3 deletions

diff --git a/packages/main/src/index.ts b/packages/main/src/index.ts
index 4a51518..b134002 100644
--- a/packages/main/src/index.ts
+++ b/packages/main/src/index.ts
@@ -219,8 +219,8 @@ function createWindow(): Promise<unknown> {
     webContents.send(MainToRendererIpcMessage.SharedStorePatch, patch);
   });
 
-  ipcMain.on(ServiceToMainIpcMessage.ApiExposedInMainWorld, (event) => {
-    event.returnValue = event.sender.id == browserView.webContents.id
+  ipcMain.handle(ServiceToMainIpcMessage.ApiExposedInMainWorld, (event) => {
+    return event.sender.id == browserView.webContents.id
       ? serviceInject
       : null;
   });
@@ -229,7 +229,8 @@ function createWindow(): Promise<unknown> {
     try {
       switch (channel) {
         case ServiceToMainIpcMessage.ApiExposedInMainWorld:
-          // Synchronous message must be handled with `ipcMain.on`
+          // Asynchronous message with reply must be handled in `ipcMain.handle`,
+          // otherwise electron emits a no handler registered warning.
           break;
         case ServiceToMainIpcMessage.SetUnreadCount:
           console.log('Unread count:', unreadCount.parse(args[0]));