Can't do async data migrations in the sync upgrade function

It seems that all methods of retrieving items from a store return a promise, which can’t be awaited in the upgrade function.

Let’s say my blogPost type has changed. The ID used to be a number, but is now a string, Then it would be nice to be able to do something like this:

upgrade(db, oldVersion, newVersion, transaction) {
           const blogPosts = await db.getAll('blogPosts') // Oh, no! We can't await anything here
           db.deleteObjectStore('blogPosts')
           // Re-create the store with the new schema
           // Remap and save all the items
      }

It would be nice if the upgrade function was async so that this type of thing can be done.

Is there any workaround for this?

[lkarabeg]

That’s amazing, thanks for your help!

[jakearchibald]

No problem! The lifetime of IDB transitions is pretty weird, unfortunately I can’t really change that 😄